Humans to Asteroids: Watch Out!

A FEW weeks ago, an asteroid almost 30 feet across and zipping along at 38,000 miles per hour flew 28,000 miles above Singapore. Why, you might reasonably ask, should non-astronomy buffs care about a near miss from such a tiny rock? Well, I can give you one very good reason: asteroids don’t always miss. If even a relatively little object was to strike a city, millions of people could be wiped out.

Thanks to telescopes that can see ever smaller objects at ever greater distances, we can now predict dangerous asteroid impacts decades ahead of time. We can even use current space technology and fairly simple spacecraft to alter an asteroid’s orbit enough to avoid a collision. We simply need to get this detection-and-deflection program up and running.

President Obama has already announced a goal of landing astronauts on an asteroid by 2025 as a precursor to a human mission to Mars. Asteroids are deep-space bodies, orbiting the Sun, not the Earth, and traveling to one would mean sending humans into solar orbit for the very first time. Facing those challenges of radiation, navigation and life support on a months-long trip millions of miles from home would be a perfect learning journey before a Mars trip.

Near-Earth objects like asteroids and comets — mineral-rich bodies bathed in a continuous flood of sunlight — may also be the ultimate resource depots for the long-term exploration of space. It is fantastic to think that one day we may be able to access fuel, materials and even water in space instead of digging deeper and deeper into our planet for what we need and then dragging it all up into orbit, against Earth’s gravity.

Most important, our asteroid efforts may be the key to the survival of millions, if not our species. That’s why planetary defense has occupied my work with two nonprofits over the past decade.

To be fair, no one has ever seen the sort of impact that would destroy a city. The most instructive incident took place in 1908 in the remote Tunguska region of Siberia, when a 120-foot-diameter asteroid exploded early one morning. It probably killed nothing except reindeer but it flattened 800 square miles of forest. Statistically, that kind of event occurs every 200 to 300 years.

Luckily, larger asteroids are even fewer and farther between — but they are much, much more destructive. Just think of the asteroid seven to eight miles across that annihilated the dinosaurs (and 75 percent of all species) 65 million years ago.

With a readily achievable detection and deflection system we can avoid their same fate. Professional (and a few amateur) telescopes and radar already function as a nascent early warning system, working every night to discover and track those planet-killers. Happily, none of the 903 we’ve found so far seriously threaten an impact in the next 100 years.

Although catastrophic hits are rare, enough of these objects appear to be or are heading our way to require us to make deflection decisions every decade or so. Certainly, when it comes to the far more numerous Tunguska-sized objects, to date we think we’ve discovered less than a half of 1 percent of the million or so that cross Earth’s orbit every year. We need to pinpoint many more of these objects and predict whether they will hit us before it’s too late to do anything other than evacuate ground zero and try to save as many lives as we can.

So, how do we turn a hit into a miss? While there are technical details galore, the most sensible approach involves rear-ending the asteroid. A decade or so ahead of an expected impact, we would need to ram a hunk of copper or lead into an asteroid in order to slightly change its velocity. In July 2005, we crashed the Deep Impact spacecraft into comet Tempel 1 to learn more about comets’ chemical composition, and this proved to be a crude but effective method.

It may be necessary to make a further refinement to the object’s course. In that case, we could use a gravity tractor — an ordinary spacecraft that simply hovers in front of the asteroid and employs the ship’s weak gravitational attraction as a tow-rope. But we don’t want to wait to test this scheme when potentially millions of lives are at stake. Let’s rehearse, at least once, before performing at the Met!

The White House Office of Science and Technology Policy has just recommended to Congress that NASA begin preparing a deflection capacity. In parallel, my fellow astronaut Tom Jones and I led the Task Force on Planetary Defense of the NASA Advisory Council. We released our report a couple of weeks ago, strongly urging that the financing required for this public safety issue be added to NASA’s budget.

This is, surprisingly, not an expensive undertaking. Adding just $250 million to $300 million to NASA’s budget would, over the next 10 years, allow for a full inventory of the near-Earth asteroids that could do us harm, and the development and testing of a deflection capacity. Then all we’d need would be an annual maintenance budget of $50 million to $75 million.

By preventing dangerous asteroid strikes, we can save millions of people, or even our entire species. And, as human beings, we can take responsibility for preserving this amazing evolutionary experiment of which we and all life on Earth are a part.

Russell Schweickart, a former astronaut, was the co-chairman of the Task Force on Planetary Defense of the NASA Advisory Council.

__________

Full article and photo: http://www.nytimes.com/2010/10/26/opinion/26schweickart.html

Read Full Post »

Two Exoplanets May Support Life

The Twin Earths of Gliese 581

An artist’s conception of the four inner planets surrounding Gliese 581, a red dwarf star 20 light years away from Earth. The large earth-like planet in the foreground is the recently discovered “Gliese 581 g,” which has an orbit of 36.6 days in the middle of the star’s habitable zone.

Two planets similar to Earth have been discovered circling the dwarf star Gliese 581. Scientists believe the pair could be inhabitable and using new, super telescopes, astronomers are now searching for signs of life.

The alien sun, glowing blood-red in the sky, provides little light and heat. But it does shine day and night throughout the year, which lasts only about two Earth months on this distant planet.

The other side of the planet, however, is in constant darkness, never illuminated by the dwarf star. Extreme temperature differences trigger mega-storms that make terrestrial hurricanes look like gentle breezes, as powerful winds drive massive waves against the coastlines.

There is no doubt about it: this is not a cozy place. And yet it is quite possible that it supports life.

Looking for Earth’s Twin

This is the exciting conclusion that was reached by Harvard astronomer Lisa Kaltenegger and her research team. The scientists performed an extensive simulation of the planet Gliese 581 d, the results of which will be described in an upcoming issue of the Astrophysical Journal. “It’s a fascinating new world,” says Kaltenegger, who has been conducting her research at the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany since the end of September. “There is actually a possibility that it’s habitable.”

Water Could Flow

Gliese is considered the most exciting planetary system astronomers have discovered to date outside our own solar system. A total of six planets orbit the red sun in the Libra constellation. Only last week, US scientists announced that they had discovered another planet in the system that’s even more similar to Earth. The smaller, rocky planet Gliese 581 g also appears to orbit its sun in the “habitable zone.” Kaltenegger has already begun calculating the climate for this satellite.

The most important requirement to allow for the development of life as we know it is that a planet is heated by its sun to a sufficiently moderate degree that liquid water can form there. “If the ingredients are right,” says MPIA Director Thomas Henning, “it could happen almost automatically.”

Now the calculations of Kaltenegger’s team are fueling the suspicion that there might even be a few oases of life among the roughly 500 planets already discovered outside our solar system, that have remained unnoticed until now.

At first Gliese 581 d, which was discovered in 2007, was also believed to be an icy planet incapable of supporting life. Initial estimates indicated that its orbital path was in fact too far from its star, meaning it was but a flying ball of ice with temperatures constantly hovering around minus 40 degrees Celsius (minus 40 degrees Fahrenheit).

But there was one factor the astronomers hadn’t taken sufficiently into account: the greenhouse effect.

The Aliens Would Need More Muscles

Gliese 581 d is seven times as heavy as the Earth, which puts it in the class of the so-called super-Earth planets. There is every indication that because of the massive rocky planet, powerful volcanoes once spewed massive amounts of CO² into the atmosphere, far more CO², in fact, than exists in our atmosphere. This could have produced a dense envelope of air under high atmospheric pressure. The resulting greenhouse gas effect would have caused temperatures to rise significantly above freezing, leading to a thaw on the icy planet.

Based on her model calculations, Kaltenegger speculates that atmospheric pressure on the planet could even be as high as seven or eight bars, a level found on Earth at the bottom of lakes. “It would certainly be extremely difficult to move around there,” the astronomer explains, “sort of like constantly wading in deep water.”

Kaltenegger’s calculations also indicate that gravity is higher on the planet. Even a slender earthling would weigh about as much as an adult male gorilla on Gliese 581 d.

“For land dwellers, in particular, it would certainly be advantageous to have a few extra muscles,” Kaltenegger speculates. “Or else the aliens would have to crawl along the ground like snakes.”

Shrubs Could Have Leaves Black As Coal

A noticeably more earth-like gravitational environment is likely to prevail on the newly discovered neighboring planet, Gliese 581 g, with a mass only three to four times that of the Earth. However, it is not yet clear whether the planet’s climate can support life. According to initial rough estimates, temperatures on Gliese 581 g, which presumably lacks a significantly warming greenhouse effect, are more freezer-like.

The possibility of vegetation on the Gliese planets is also a source of speculation. If plant-like beings did exist there, they would probably look extremely exotic to our eyes. But because the star provides so little light, the alien plants would have to utilize all available light for their photosynthesis. The consequence, as US scientist Nancy Kiang has discovered, would be bizarre. According to Kiang, for grasses or shrubs to thrive under a red sun, their blades and leaves would have to be black as coal.

All of this, so far, is little more than conjecture, albeit with scientific underpinnings. But with the right telescopes and measuring instruments, it would, in fact, be possible, one day, to determine whether there are trees and other vegetation growing on the two earth-like Gliese planets.

To reach this determination, scientists would have to capture the light from the planet and use it to decode the chemical composition of their atmospheres. A high oxygen concentration alone would indicate that life exists there, because oxygen is a highly reactive gas that can only exist in small amounts in the atmosphere of an uninhabited planet. A high oxygen concentration would mean that there must be organisms like bacteria and plants on the planet to constantly produce more oxygen.

The Firefly And The Headlight

But analyzing the light coming from an extrasolar planet, or exoplanet, remains an enormous technical challenge. Normal stars shine millions of times more brightly than their dimly lit satellites. The task of detecting a planet the size of Earth near a distant sun is about equivalent to detecting a firefly flying next to a car headlight in Cairo — from Berlin.

Scientists have a long way to go before they can unlock the secrets of the atmospheres of rocky planets like Gliese 581 d or Gliese 581 g, which makes the breakthroughs astronomers have been able to announce in recent years all the more astonishing. They have already been able to study the atmospheres of larger exoplanets, at least indirectly. To do this, they take advantage of mini solar eclipses that occur when a distant planet passes in front of its sun. When this happens, the planet is uniformly illuminated, leaving its chemical fingerprint on the light emitted by the star.

For now, this trick only works with gas planets, which have enormous atmospheres. The atmospheres of exoplanets analyzed to date contain mostly hydrogen and helium, a composition very similar to that of Jupiter and Saturn. This confirms that our solar system is not an exception in the Milky Way.

Early this year, MPIA scientists even managed, for the first time, to directly capture and analyze the light coming from a distant planet. To do so, they used the world’s most advanced observatory, the European-run “Very Large Telescope” in Chile’s Atacama Desert. Its eight-meter mirrors are so photosensitive that they could detect a flashlight on the moon. But even this is only good enough for only a very few of the exoplanets. The impressive achievement was only possible because the planet the scientists were studying, the gas giant HR 8799 c, is unusually bright. HR 8799 c is still very young and as hot as a flamethrower.

New Telescopes on The Horizon

Astrophysicists are confident in their ability to make rapid headway in pushing the boundaries even farther, and they are eager to directly photograph smaller and colder planets. “We are moving forward much more quickly than expected,” says Max Planck scientist Henning. “In as little as five years, we could be far enough along to measure the atmospheres of super-Earth planets orbiting small, relatively dim suns for the first time.”

Scientists like Henning are pinning their hopes on the next generation of eyes in the sky. The James Webb Space Telescope, the successor of the legendary Hubble Space Telescope, could be sent into space by as early as 2014. The Europeans, for their part, plan to build another observatory, the “Extremely Large Telescope,” in the Atacama Desert. With its 42-meter mirror, it would be the biggest telescope ever built. There are even plans in the works to build a 100-meter telescope.

These super observatories should allow scientists to solve the mysteries of the Gliese planets. And what if their remote diagnosis reveals that there are, in fact, unknown life forms there? Could mankind launch an expedition to explore the alien worlds?

The Gliese system is only 20.5 light-years away from Earth, making the red dwarf star one of the 100 closest fixed stars — a cosmic neighbor, so to speak.

But even this relatively small interstellar chasm could not be crossed with conventional rockets. To reach the twin earthlike planets, terrestrial astronauts would have to travel for 400,000 years. Man has only existed for half as long.

__________

Full article and photos: http://www.spiegel.de/international/zeitgeist/0,1518,721840,00.html

Read Full Post »

In the Habitable Zone

A planet orbiting a star causes a slight disturbance in the star’s rotation, the effect of the gravitational tug between the star and the planet. Astronomers have been studying the wobbling of stars for a couple of decades, in hopes of finding an exoplanet — a planet beyond our solar system — that might offer the possibility of sustaining human life. Now, after 11 years of searching with specialized instruments in Chile and Hawaii, a team of American astronomers has announced in the Astrophysical Journal that it has found the first likely candidate.

The planet is called Gliese 581g after its sun, Gliese 581, a red dwarf vastly dimmer than our sun and about 20 light-years from Earth. Potentially habitable does not mean Earthlike. It means that Gliese 581g is the right distance from its sun to be in the habitable zone, able to sustain liquid water and with enough gravity to retain an atmosphere. Gliese 581g orbits its sun in a bit more than 36 days and is almost certainly tidally locked, meaning the same side of the planet always faces the sun. That probably means wide extremes in temperature and a permanent twilight zone between night and day where the climates are more moderate.

What makes this discovery so important is that it happened so early in the search for exoplanets and after examining only a tiny sample of small candidate stars as close to Earth as Gliese 581. In the paper reporting their discovery, the astronomers discuss the probable implications with carefully calibrated language that still doesn’t hide their excitement. “If the local stellar neighborhood,” they write, “is a representative sample of the galaxy as a whole, our Milky Way could be teeming with potentially habitable planets.” We are intrigued, too.

___________

Editorial, New York Times

__________

Full article: http://www.nytimes.com/2010/10/01/opinion/01fri4.html

Read Full Post »

Don’t talk to aliens, warns Stephen Hawking

Hawking has depicted what kinds of alien could be out there

THE aliens are out there and Earth had better watch out, at least according to Stephen Hawking. He has suggested that extraterrestrials are almost certain to exist — but that instead of seeking them out, humanity should be doing all it that can to avoid any contact.

The suggestions come in a new documentary series in which Hawking, one of the world’s leading scientists, will set out his latest thinking on some of the universe’s greatest mysteries.

Alien life, he will suggest, is almost certain to exist in many other parts of the universe: not just in planets, but perhaps in the centre of stars or even floating in interplanetary space.

Hawking’s logic on aliens is, for him, unusually simple. The universe, he points out, has 100 billion galaxies, each containing hundreds of millions of stars. In such a big place, Earth is unlikely to be the only planet where life has evolved.

“To my mathematical brain, the numbers alone make thinking about aliens perfectly rational,” he said. “The real challenge is to work out what aliens might actually be like.”

The answer, he suggests, is that most of it will be the equivalent of microbes or simple animals — the sort of life that has dominated Earth for most of its history.

One scene in his documentary for the Discovery Channel shows herds of two-legged herbivores browsing on an alien cliff-face where they are picked off by flying, yellow lizard-like predators. Another shows glowing fluorescent aquatic animals forming vast shoals in the oceans thought to underlie the thick ice coating Europa, one of the moons of Jupiter.

Such scenes are speculative, but Hawking uses them to lead on to a serious point: that a few life forms could be intelligent and pose a threat. Hawking believes that contact with such a species could be devastating for humanity.

He suggests that aliens might simply raid Earth for its resources and then move on: “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet. I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach.”

He concludes that trying to make contact with alien races is “a little too risky”. He said: “If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the Native Americans.”

The completion of the documentary marks a triumph for Hawking, now 68, who is paralysed by motor neurone disease and has very limited powers of communication. The project took him and his producers three years, during which he insisted on rewriting large chunks of the script and checking the filming.

John Smithson, executive producer for Discovery, said: “He wanted to make a programme that was entertaining for a general audience as well as scientific and that’s a tough job, given the complexity of the ideas involved.”

Hawking has suggested the possibility of alien life before but his views have been clarified by a series of scientific breakthroughs, such as the discovery, since 1995, of more than 450 planets orbiting distant stars, showing that planets are a common phenomenon.

So far, all the new planets found have been far larger than Earth, but only because the telescopes used to detect them are not sensitive enough to detect Earth-sized bodies at such distances.

Another breakthrough is the discovery that life on Earth has proven able to colonise its most extreme environments. If life can survive and evolve there, scientists reason, then perhaps nowhere is out of bounds.

Hawking’s belief in aliens places him in good scientific company. In his recent Wonders of the Solar System BBC series, Professor Brian Cox backed the idea, too, suggesting Mars, Europa and Titan, a moon of Saturn, as likely places to look.

Similarly, Lord Rees, the astronomer royal, warned in a lecture earlier this year that aliens might prove to be beyond human understanding.

“I suspect there could be life and intelligence out there in forms we can’t conceive,” he said. “Just as a chimpanzee can’t understand quantum theory, it could be there are aspects of reality that are beyond the capacity of our brains.”

__________

Full article and photo: http://www.timesonline.co.uk/tol/news/science/space/article7107207.ece

Read Full Post »

Reaching for the Stars When Space Was a Thrill

Using aviation industry ads, a new book revisits a time when outer space still thrilled, and cold war paranoia reigned.

The years from 1957 to 1962 were a golden age of science fiction, as well as paranoia and exhilaration on a cosmic scale. The future was still the future back then, some of us could dream of farms on the moon and heroically finned rockets blasting off from alien landscapes. Others worried about Russian moon bases.

Scientists debated whether robots or humans should explore space. Satellites and transistors were jazzy emblems of postwar technology, and we were about to unravel the secrets of the universe and tame the atom (if it did not kill us first).

Some of the most extravagant of these visions of the future came not from cheap paperbacks, but from corporations buffing their high-tech credentials and recruiting engineering talent in the heady days when zooming budgets for defense and NASA had created a gold rush in outer space.

In the pages of magazines like Aviation Week, Missiles and Rockets and even Fortune, companies, some famous and some now obscure, were engaged in a sort of leapfrog of dreams. And so, for example, Republic Aviation of Farmingdale, N.Y. — “Designers and Builders of the Incomparable Thundercraft” — could be found bragging in Aviation Week and Space Technology magazine in 1959 about the lunar gardening experiments it was doing for a future Air Force base on the moon.

Or the American Bosch Arma Corporation showing off, in Fortune, its “Cosmic Butterfly,” a solar-powered electrically propelled vehicle to ferry passengers and cargo across the solar system.

Most Americans never saw these concoctions, but now they have been collected and dissected by Megan Prelinger, an independent historian and space buff, in a new book, “Another Science Fiction: Advertising the Space Race 1957-1962.” It is being published on May 25 by Blast Books.

Ms. Prelinger and her husband, Rick, operate the Prelinger Library, a private research library in San Francisco with a heavy emphasis on media, technology and landscape history.

In an e-mail message, Ms. Prelinger said she had grown up “on a cultural diet of science fiction and space,” memories of the moon landings and “Star Trek” merging in her mind. “As a result,” she said, “I grew up believing that I was a junior member of an advanced technological society.”

The book, she said, was inspired by a shipment of old publications to the library, including Aviation Week & Space Technology and Missiles and Rockets. “I little expected that the advertising in their pages would seize my attention more than the articles themselves,” she writes in the introduction to her book.

The ads are chock-full of modernist energy and rich in iconography in ways Ms. Prelinger is happy to elaborate on.

The late ’50s were also the years of the Organization Man. The cover illustration, from an insurance ad, shows a man in a gray flannel suit who is a dead ringer for the existentially confused Don Draper of “Mad Men,” floating alarmed and bewildered among the planets and stars. Time and again, the mountains and valleys of the moon, for example, are portrayed as if they were the mountains, canyons and deserts of the American West, making the space program just another chapter in the ongoing narrative of Manifest Destiny.

In one illustration, the hands of God and Adam from Michelangelo’s Sistine Chapel ceiling have been transformed into a giant pair of space gloves reaching for each other. In another, the silhouette of a spaceship forms a cross.

“These images suggest that the furthest reach of what humankind hoped to find in space was in fact the very essence of infinity,” Ms. Prelinger writes.

Leafing through this book is a walk down my own memory lane. I grew up in Seattle, which was a one-company town dominated by Boeing. Almost everybody worked there sooner or later. My best friend’s father helped design the Saturn V rocket that lifted humans to the moon. After limping out of M.I.T. with a physics degree in the late ’60s, I, too, worked there for a year, playing a kind of space war — shooting high-speed aluminum balls at sheets of aluminum arrayed to simulate the structures of aircraft or spacecraft, to see what the damage would be under various conditions. At the end of the day, my desk was buried in piles of sharp dented and charred sheets of aluminum. I had to count all the holes.

It’s hard to know what to be more nostalgic about, all those childhood dreams of space opera or the optimism of an era in which imagination and technology were booming and every other ad ended with a pitch to come work for the thriving company of the future. “To advance yourself professionally, you should become a member of one these teams. Write to N. M. Pagan,” reads a typical notice from the Martin Company, now part of Lockheed Martin.

You don’t hear that much these days.

Back then, you, too, sitting at a drafting table or in a cubicle, designing antennas or self-locking nuts among acres of such boards and cubicles — “Reaching for the Moon, Mr. Designer?” reads a Kaylock ad — could be a space hero.

And of course it was almost exclusively men depicted in the ads. One exception was an ad from the National Cash Register Company for a new electronic machine for posting checks. “And what the POST-TRONIC does electronically the operator cannot do wrong — because she doesn’t do it at all!” says the ad showing a woman floating in space at the machine’s console.

Naturally, there was a hook to those recruitment ads, as Ms. Prelinger points out. The real business of most of those aerospace companies was not the space program but defense — building fighters, bombers, missiles and other implements of the cold war, not to mention commercial airliners. For many of these places, the space program was more of a hindrance than a boost to the bottom line, a sort of prestigious loss leader to attract cutting-edge talent.

Occasionally, as Ms. Prelinger reports, the darker side of this work bled through into the trade press and the ads, like when the Marquardt Corporation, which made small control rockets for satellites, showed a spy satellite aiming its lens down at Earth.

If the space fever began in 1957 with Sputnik, it cooled by 1962, when the basic plan for the Apollo moon missions was set and there was no more space for imaginations to run wild. Also, by then NASA’s budget was leveling off. Ms. Prelinger said that during this period about half a million engineers, scientists, draftsmen and other people followed the clarion call to blend their talents into the new age, swelling the ranks of aerospace workers to more than a million.

Some of them might have wound up like me. When the “impact mechanics” group was downsized, I was sent to the “weights and measures” group. Our job was to scrutinize rocket blueprints to determine the position and weight of every nut, bolt, washer and any other item on a small upper-stage booster that was to deliver an unknown payload to orbit. The information could be entered into a computer program that would calculate the center of gravity and other dynamical properties of the rocket package.

It was essential but brain-numbing work, and I learned a lot about shooting rubber bands from the wars that broke out every day after lunch.

But it was men and women like these, working in cubicles, who saved the astronauts of Apollo 13 in 1969, by figuring out how to bring them back from the moon alive in a crippled spacecraft.

In the wake of the moon landings and then the end of the cold war, many of those jobs, exciting or not, disappeared, as did many of the companies that advertised them. What has not disappeared in all these years and decades is the yearning and arguing about space.

We’re still fighting about what NASA should do as far as human exploration of the universe is concerned, collectively looking more and more like that bewildered advertising man floating in space on the cover of Ms. Prelinger’s fascinating book. The argument has been going on for my whole life. Since those advertisements appeared, the United States invaded Vietnam and left; the Soviet Union crumbled and China rose; the whole nation stopped smoking.

We never did find the essence of infinity — at least not yet.

Dennis Overbye, New York Times

__________

Full article and photos: http://www.nytimes.com/2010/03/09/science/space/09space.html

Read Full Post »

From the Clash of White Dwarfs, the Birth of a Supernova

STAR A Type 1a supernova is seen to the bottom left of a galaxy in the Virgo cluster.

How many ways can a star go “kaboom!”? It might depend on what kind of galaxy the star lives in, astronomers said last week.

For the last 20 years, astronomers seeking to measure the cosmos have used a special type of exploding star, known as Type 1a supernovas, as distance markers. They are thought to result when stars known as white dwarfs grow beyond a certain weight limit, setting off a thermonuclear cataclysm that is not only bright enough to be seen across the universe but is also remarkably uniform from one supernova to the next. Using them, two teams of astronomers a little more than a decade ago reached the startling and now widely held conclusion that some “dark energy” was speeding up the expansion of the universe.

But astronomers, to their embarrassment, have not been able to agree on how the white dwarf gains its fatal weight and explodes, whether by slowly grabbing material from a neighboring star or by crashing into another white dwarf.

In a telephone news conference on Wednesday and a paper published Thursday in the journal Nature, Marat Gilfanov and his colleague, Akos Bogdan, both of the Max Planck Institute for Astrophysics in Garching, Germany, said that for at least one class of galaxies in the universe, the roundish conglomerations of older, redder stars known as ellipticals, these supernovas are mostly produced by collisions.

“We have revealed the source of the most important explosions in cosmology,” Dr. Gilfanov said, adding that until now “we didn’t know exactly what they were.”

Reasoning that white dwarfs slowly gobbling gas from neighbors would emit X-rays as the captured gas fell and was heated, Dr. Gilfanov and Dr. Bogdan used NASA’s Chandra X-Ray Observatory to look at five elliptical galaxies and the central bulge of the nearby Andromeda galaxy — all of which are composed of older stars. The satellite recorded only about one-thirtieth to one-fiftieth of the X-rays that would be expected from such white dwarfs, leading the astronomers to conclude that no more than 5 percent of the supernovas in those types of stellar systems could be produced by accreting white dwarfs.

The observations leave open the possibility that accreting dwarfs might be responsible for more of the supernovas in spiral galaxies like our own, which tend to have younger, more massive stars.

That leaves open the possibility of two different kinds of Type 1a supernovas at loose in the universe and could add extra uncertainty into efforts to use exploding stars as standard candles to make precise measurements of the universe. Accreting white dwarfs go off at a precisely determined mass known as the Chandrasekhar limit, but a pair of colliding dwarfs could have a range of masses.

Mario Livio, a theorist at the Space Telescope Science Institute, said that while the new results and the idea of two classes of supernovas “muddies the water,” they would not affect the measurements of dark energy. Most of the supernovas in those studies, he said, came from spiral galaxies, and the astronomers, moreover, were very careful to calibrate their data.

“The main results so far will remain unchanged,” Dr. Livio said.

Adam Riess, of Johns Hopkins University and the Space Telescope Science Institute and a first-rate dark energy hunter, called the new paper “an interesting study.” He compared the two theories of supernovas to lighting a stick of dynamite with a fuse versus banging them together to see if they would go off. “If we find a connection to where nature does it one way versus the other, we could use that information to improve the use of these candles,” Dr. Riess wrote in an e-mail message. “I think we are getting close to that point now.”

Dennis Overbye, New York Times

__________

Full article and photo: http://www.nytimes.com/2010/02/23/science/space/23star.html

Read Full Post »

Closing the new frontier

“We have an agreement until 2012 that Russia will be responsible for this,” says Anatoly Perminov, head of the Russian space agency, about ferrying astronauts from other countries into low-Earth orbit. “But after that? Excuse me, but the prices should be absolutely different then!”

The Russians may be new at capitalism, but they know how it works. When you have a monopoly, you charge monopoly prices. Within months, Russia will have a monopoly on rides into space.

By the end of this year, there will be no shuttle, no U.S. manned space program, no way for us to get into space. We’re not talking about Mars or the moon here. We’re talking about low-Earth orbit, which the United States has dominated for nearly half a century and from which it is now retiring with nary a whimper.

Our absence from low-Earth orbit was meant to last a few years, the interval between the retirement of the fatally fragile space shuttle and its replacement with the Constellation program (Ares booster, Orion capsule, Altair lunar lander) to take astronauts more cheaply and safely back to space.

But the Obama 2011 budget kills Constellation. Instead, we shall have nothing. For the first time since John Glenn flew in 1962, the United States will have no access of its own for humans into space — and no prospect of getting there in the foreseeable future.

Of course, the administration presents the abdication as a great leap forward: Launching humans will be turned over to the private sector, while NASA’s efforts will be directed toward landing on Mars.

This is nonsense. It would be swell for private companies to take over launching astronauts. But they cannot do it. It’s too expensive. It’s too experimental. And the safety standards for getting people up and down reliably are just unreachably high.

Sure, decades from now there will be a robust private space-travel industry. But that is a long time. In the interim, space will be owned by Russia and then China. The president waxes seriously nationalist at the thought of China or India surpassing us in speculative “clean energy.” Yet he is quite prepared to gratuitously give up our spectacular lead in human space exploration.

As for Mars, more nonsense. Mars is just too far away. And how do you get there without the stepping stones of Ares and Orion? If we can’t afford an Ares rocket to get us into orbit and to the moon, how long will it take to develop a revolutionary new propulsion system that will take us not a quarter-million miles but 35 million miles?

To say nothing of the effects of long-term weightlessness, of long-term cosmic ray exposure, and of the intolerable risk to astronaut safety involved in any Mars trip — six months of contingencies vs. three days for a moon trip.

Of course, the whole Mars project as substitute for the moon is simply a ruse. It’s like the classic bait-and-switch for high-tech military spending: Kill the doable in the name of some distant sophisticated alternative, which either never gets developed or is simply killed later in the name of yet another, even more sophisticated alternative of the further future. A classic example is the B-1 bomber, which was canceled in the 1970s in favor of the over-the-horizon B-2 stealth bomber, which was then killed in the 1990s after a production run of only 21 (instead of 132) in the name of post-Cold War obsolescence.

Moreover, there is the question of seriousness. When John F. Kennedy pledged to go to the moon, he meant it. He had an intense personal commitment to the enterprise. He delivered speeches remembered to this day. He dedicated astronomical sums to make it happen.

At the peak of the Apollo program, NASA was consuming almost 4 percent of the federal budget, which in terms of the 2011 budget is about $150 billion. Today the manned space program will die for want of $3 billion a year — 1/300th of last year’s stimulus package with its endless make-work projects that will leave not a trace on the national consciousness.

As for President Obama’s commitment to beyond-lunar space: Has he given a single speech, devoted an iota of political capital to it?

Obama’s NASA budget perfectly captures the difference in spirit between Kennedy’s liberalism and Obama’s. Kennedy’s was an expansive, bold, outward-looking summons. Obama’s is a constricted, inward-looking call to retreat.

Fifty years ago, Kennedy opened the New Frontier. Obama has just shut it.

Charles Krauthammer, Washington Post

__________

Full article: http://www.washingtonpost.com/wp-dyn/content/article/2010/02/11/AR2010021103484.html

Read Full Post »

Space to thrive

NASA’s new mission

A plan to overhaul America’s space agency is long overdue

IN 2004 George Bush announced a plan for America’s space agency, NASA, to return to the moon by 2020, land there, explore the surface and set up a base. The moon would then serve as a staging post for a journey to Mars. It was, unfortunately, unclear how this modest proposal would be paid for and, as work began and costs spiralled, the “vision” seemed more science fiction than science.

On February 1st, reality caught up. The back-to-the-moon programme, Constellation, with its Ares rocket (pictured), fell victim to Barack Obama’s need to find cuts. The Office of Management and Budget described it as over budget, behind schedule and lacking in innovation due to a failure to invest. The office also said Constellation had sucked money from other, more scientific programmes, such as robotic space exploration and Earth observation.

Much has been made of the fact that NASA will, as a consequence of Constellation’s cancellation, have to rely on private firms to send its astronauts to the international space station once the space shuttle is withdrawn. In many ways, though, this is the least interesting aspect of what is happening, for what Mr Obama proposed is actually a radical overhaul of the agency.

Success is an option

The rethink looks at four areas: new ways of getting into space; extending the life and use of the space station; the agency’s relationship with the private sector; and its scientific mission. The first part of the plan, known as the transformative technology initiative, will cost $7.8 billion over five years. It will develop orbiting fuel depots, rendezvous-and-docking technologies, advanced life-support systems that recycle all of their materials, and better motors for spacecraft. The agency will also develop new engines, propellants and materials as part of a $3.1 billion heavy-lift programme, to allow it to send craft well beyond Earth, while $4.9 billion is allowed for advances in areas such as sensors, communications and robotics.

The second part of the plan is to postpone the death of the space station from 2016 to 2020. More science will be done there (cynics might take issue with the word “more”) and there will, specifically, be research into biology, combustion and materials science. There will also be more emphasis on space medicine, and the station is to get a centrifuge. This will allow people to experience artificial gravity in space, which may be important for long-term missions to places such as Mars. Inflatable “space habitats” were mentioned, and these might be used to build extensions to the space station on the cheap. All this will please the station’s other participants—Canada, Europe and Japan—which have invested a lot in it for, as yet, little return. It will also help build a coalition of countries that want to travel farther into the solar system.

Now Constellation is cancelled, the plan’s third part is to encourage private firms to provide transport to and from the space station. Such journeys into low Earth orbit do not need the heavy-lifting oomph that more wide-ranging missions require, so the proposal is to contract out all of this local delivery work. In fact, such a scheme already exists, and 20 cargo missions by two firms, SpaceX and Orbital Sciences, are planned. The scheme will be extended to include at least two other companies, Boeing and Sierra Nevada Corporation.

Under the new regime, companies will get fixed-price contracts instead of being paid on a “cost plus” basis. The risks and burdens of developing transport to low Earth orbit will thus fall to the private sector. According to Mike Gold of Bigelow Aerospace, a firm that hopes to build inflatable space habitats, such fiscal rectitude has been met with criticism from a surprising quarter: Republican politicians. Bill Posey, who represents Florida in Congress, described it as a “slow death of our nation’s human space-flight programme”. “If you could fuel a rocket on hypocrisy,” Mr Gold suggests, “we’d be on Pluto by now.”

The last part of the plan is for more science. The Earth-observation programme will receive some $2 billion to improve the forecasting of climate change and monitor the planet’s carbon cycle and its ice sheets. As part of this, NASA will replace the Orbiting Carbon Observatory, a satellite that was lost a year ago, and which was supposed to identify the world’s sources, and sinks, of carbon dioxide.

There will also be a new emphasis on robotic missions, which are vastly cheaper than manned ones, and cause less angst if they blow up. The first robot destination will be the moon. There will also, according to Charlie Bolden, NASA’s administrator, be a mission to the sun, to study the solar wind, and one to improve the agency’s ability to detect and catalogue interesting (but potentially dangerous) asteroids that pass near Earth.

It all, then, adds up to a radical shift—but a sensible one after years of fantasy. As Lori Garver, Mr Bolden’s deputy, put it, “the old plans lost us the moon. This gives us back the solar system.”

__________

Full article and photo: http://www.economist.com/sciencetechnology/displayStory.cfm?story_id=15449787&source=features_box3

Read Full Post »

Looking for Clues in a Distant Planet’s Atmosphere

The Search for Extraterrestrial Life

For the first time, scientists have been able to analyze the atmosphere of a distant planet. The success could prove a milestone on the road toward finding life beyond our solar system.

The heart of European efforts to analyze distant planets is located in the middle of Chile’s Atacama Desert, far away from civilization. The “Very Large Telescope” was recently able to capture the weak light emitted from a planet known as HR 8799 c. By means of spectroscopy, scientists were able to analyze its atmosphere.

Its atmosphere is stiflingly hot, with temperatures generally hovering around 800 degrees Celsius (1,470 degrees Fahrenheit) — in the shade. The air is filled with billowing clouds of highly toxic gas.

Anyone setting foot on this faraway planet would die a speedy death. Nevertheless, the recently launched study of HR 8799 c is a breakthrough in the search for extraterrestrial life.

Astronomers unveiled a groundbreaking achievement in the field of metrology last week. By measuring the spectrum of light coming from HR 8799 c, they have managed to determine the chemical composition of its atmosphere. “For the first time, we have directly obtained the spectrum of a planet outside our solar system,” says study co-author Wolfgang Brandner of the Max Planck Institute for Astronomy in Heidelberg.

Nowadays, the discovery of planets outside our solar system has become practically routine. In recent years, scientists have discovered more than 400 of these so-called exoplanets. But in most cases, their existence could only be proven indirectly, for example, by virtue of the fact that they cause a slight weakening in the light emitted by a much brighter star.

Mechanical Ballet

Only with the help of the world’s most advanced observatory, and the European-run “Very Large Telescope” (VLT), did it become possible to directly capture the weak light coming from a planet and analyzing it using spectroscopy. The massive telescope is located on a 2,600-meter (8,528-foot) peak in Chile’s Atacama Desert.

After nightfall, the robotic eyes come to life on the mountain, known as Cerro Paranal. Four giant domes, as outlandish as the stone sculptures on the Easter Islands, are silhouetted against the evening sky. The steel giants begin moving almost inaudibly, as the domes, each a 400-ton maze of cables and supports, ladders and steps, perform a mechanical ballet.

Each of the VLT’s four main mirrors has a diameter of more than eight meters. They are the most sensitive devices designed to peer at the sky ever built by human hands, so powerful that they could pinpoint the light coming from a car headlight on the moon. One of their most important objectives is the search for a second Earth — and for extraterrestrial life in space.

“What we are currently experiencing is the emergence of a new conception of the world,” says Michael Sterzik, “comparable to the sea change that occurred when Copernicus described how the earth revolves around the sun.” The astrophysicist climbs down the steps of the VLT and locks the door from the outside. His presence would only disturb the images. He is the head of operations at the European Southern Observatory (ESO), which operates the VLT as part of a consortium of 14 European countries.

Life in the Universe

The Atacama Desert is one of the driest places on the planet, which makes it ideal for obtaining a clear view into outer space. To avoid disturbing the measurements at the observatory, drivers are required to shut off their headlights and crawl, with only their parking lights turned on, up the serpentine access road, which is lined with nothing but reflectors. In October, planet hunter Brandner spent four nights at the observatory to align the telescopes with HR 8799 c. “It is now possible to control many observations via the Internet,” he says, “but our project was so experimental that we had to be on-site all the time.”

The late summer heat is currently shimmering above the giant, artificial eye. The telescope mirrors have to be recoated every 18 months because of the abrasive effect of dust storms. There is no sound of birds singing, and the only sign of life comes from the parched-looking desert plants that claw their way through the gravel. The extremely dry air, with humidity levels that are sometimes lower than 4 percent, burns the eyes and causes the skin to crack open.

The reddish, rocky desert around the VLT seems strangely familiar, reminiscent of images taken on Mars, a sterile, desert-like planet. Ironically, it is in this inhospitable place that scientists are searching for life in the universe.

A tunnel leads down to the guesthouse, half of which is buried underground to protect against the brutal desert climate. Tanker trucks deliver 55,000 liters of drinking water every day. The building has the futuristic look of a space station.

Living on Cerro Paranal is everything but glamorous. The staff works at night and sleeps during the day. The nearest city is several hours away, and alcohol is banned at the facility.

Astonishing Results

The planet hunters working with Wolfgang Brandner were initially dogged by bad luck. First the sky was overcast, and then moist layers of air obscured the view. It was only during their last night at Cerro Paranal that the scientists were lucky. For five hours, the telescope mirror followed the faraway planet as it moved across the sky in the constellation Pegasus, invisible to the naked eye.

After a long night of observation, Brandner had accumulated enough data to produce a portrait of the planet. His team packed their bags, flew home and went to work analyzing the data. The results were astonishing.

HR 8799 c is a young, hot giant planet, a cosmic teenager less than 60 million years old and more than 3,000 times as heavy as the Earth. But on Brandner’s images, the fiery giant looks more like a tiny, forlorn little dot in space. The planet is 130 light-years away from the Earth, which means that the light being captured today has been traveling since 1880 and has been weakening ever since.

“Capturing an image of it was almost impossible, because the star around which the planet revolves is brighter by several orders of magnitude,” says Sterzik. “For every particle of light coming from the planet, there are thousands coming from its central star.” The astrophysicist likens the challenge to observing a candle burning next to a 300-watt spotlight two kilometers away.

The chemical analysis of a hot giant using the VLT has been technically possible for several years, but scientists had not found a suitable object worth observing — until about a year ago, when a competing team from Canada discovered the promising planetary system that includes HR 8799 c.

Evidence of Gas Storms

When the ESO researchers analyzed the chemical fingerprint of the young gas giant, they made a surprising discovery: The methane in the gas shield appears to be combined with unusually high levels of carbon monoxide. “Carbon monoxide is normally found only in lower atmospheric layers and is thus invisible to us,” Brandner explains. “The fact that we see it around HR 8799 c could mean that there are violent storms raging on the planet.”

The evidence of gas storms on the giant planet would be an important step in the search for extraterrestrial life forms. It would allow scientists to visualize the weather, climate and even seasons of an exoplanet. But the long-term goal is still to study a small planet with pleasant temperatures that resemble our Earth. Only when scientists are able to discover traces of ozone or water vapor in the atmosphere of a planet will they have found signs of the possible existence of life.

But the smaller and colder a planet is, the more difficult it is to capture its light. Even the VLT is still only capable of detecting hot, giant objects.

To address this need, scientists at ESO headquarters in Garching, near Munich, are already planning a successor to the VLT that would be five times as big and many times as powerful: the “Extremely Large Telescope” (ELT). Negotiations are currently underway with Chile and the ESO member countries.

A nearby mountaintop within view of Cerro Paranal is already being investigated as a possible site for the ELT — a lifeless, windswept mound of rock that could serve as the starting point for finding life in the vast expanse of the universe.

__________

Full article and photo: http://www.spiegel.de/international/world/0,1518,673242,00.html

Read Full Post »

Should Old Articles Be Forgot

OVER the past year, Americans have spent an average of 11.8 hours a day consuming information, sucking up, in aggregate, 3.6 zettabytes of data and 10,845 trillion words. That, said the University of California, San Diego, researcher who computed these figures, is triple the amount of “content” that we consumed in 1980.

Thanks to this gargantuan download from all forms of media, we now know vastly more than we did a year ago about bankers’ bonuses, Sarah Palin, “death panels,” Glenn Beck, where Barack Obama was born, Jon and Kate, and cocktail waitresses who have spent quality time with Tiger Woods.

Hidden among that avalanche of diverting gigabytes were some developments of more enduring significance. Here are just a few:

ROBOTIC WARFARE The use of drones became a central part of the American antiterrorism strategy this year, with President Obama sanctioning about 50 Predator strikes — more than George W. Bush approved in his entire second term. As Jane Mayer of The New Yorker reported earlier this year, most of the targets of these assassinations were in the tribal regions of Pakistan, with as many as 500 people killed. Those killed in the missile attacks include many high-ranking Qaeda and Taliban figures and dozens of women and children who lived with them or happened to be nearby.

The military is so enthusiastic about these remotely piloted planes that it is building new ones as fast as it can (including a more heavily armed version called the Reaper). It also announced that it will deploy drones to scour the Gulf of Mexico, the Pacific Ocean and the Caribbean for drug smugglers. What’s more, the government is now working on “nano” drones the size of a hummingbird, which would be able to pursue targets into homes and buildings.

CAR CRAZY IN CHINA This year, China surpassed the United States as the largest consumer of that iconic American machine — the automobile. China’s emerging middle class has fallen in love with cars, with sales up more than 40 percent over 2008; there are now long waiting lists for the coolest and hottest models, ranging from the Buick LaCrosse to BMWs. Automakers are expected to sell 12.8 million cars and light trucks in China this year — 2.5 million more than in America.

China’s auto boom, of course, has major implications for global efforts to reduce greenhouse-gas emissions. The nation of 1.3 billion is on pace to double its consumption of gasoline and diesel over the next decade.

REAL WORKING WIVES In more than a third of American households, women are now the chief breadwinners. This reversal of traditional roles was accelerated by a brutal two-year recession, in which 75 percent of all jobs lost were held by men.

Even in homes where both spouses work, one in four wives now earns more than her husband. That’s partly because of rising education levels among women, falling salaries in manufacturing and blue-collar jobs and the growing need for both spouses to bring home a paycheck. Wives’ earnings, said Kristin Smith, a professor of sociology at the University of New Hampshire, have become “critical to keeping families afloat.”

A NEW SOURCE OF STEM CELLS Scientists re-engineered regular skin cells from mice into stem cells that are just as versatile as embryonic stem cells. To demonstrate that these re-engineered adult cells could be used to create any kind of cell in the body, the Chinese research team inserted just a few of them into placental tissue and developed them into healthy mice. “We have gone from science fiction to reality,” said Robert Lanza, a cell biologist.

If further research on the new technique proves successful, it may create a viable means for scientists to use a patient’s own tissue to produce a replacement liver, kidney or other organ — without the ethical concerns attached to the harvesting of stem cells from human embryos. But reprogramming adult cells opens the door to a new ethical problem: a rogue scientist could use the method to create human beings from a few cells scraped from a person’s arm. “All the pieces are there for serious abuse,” Mr. Lanza said.

TEEMING WITH PLANETS Astronomers are closing in on identifying distant worlds that may have the right conditions to support life. Techniques for detecting “exoplanets” are becoming more sophisticated, and over 400 have been discovered so far — 30 in October alone. This year brought two particularly intriguing finds. One is Gliese 581d, orbiting a star at a distance that could indicate surface temperatures not so different from Earth’s. Astronomers also discovered a “waterworld” composed mostly of H2O, which would be a prime candidate for extraterrestrial life if it were just a little farther from its sun.

The discovery of Earth-like planets, with water and moderate temperatures, is now so likely that the Vatican held a conference of astrobiologists this year to discuss the theological repercussions of extraterrestrial life. “If biology is not unique to the Earth, or life elsewhere differs biochemically from our version, or we ever make contact with an intelligent species in the vastness of space, the implications for our self-image will be profound,” said Chris Impey, a professor of astronomy at the University of Arizona.

Discovering that we have company in the universe, in fact, might open our eyes to what’s important on Earth.

William Falk is the editor in chief of The Week magazine.

__________

Full article: http://www.nytimes.com/2009/12/29/opinion/29falk.html

Read Full Post »

Avatar moons may become a science fact

Habitable alien moons like the one depicted in the blockbuster movie Avatar may become science fact within the next few years, according to a leading astronomer.

  In the 3D film, a race of 10ft blue-skinned giants inhabits an Earth-like moon called Pandora.

Their world orbits a gas giant planet similar to Jupiter that cannot support life.

US astronomer and planet-hunter Lisa Kaltenegger, from the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts, believes there is every chance a real-life version of Pandora exists and will soon be found.

She has conducted research showing that a planned new space telescope will be able to identify nearby “exomoons” and discover if they are habitable.

The American space agency Nasa’s James Webb Space Telescope (JWST) is due to be launched in 2014.

Dr Kaltenegger said: “If Pandora existed, we potentially could detect it and study its atmosphere in the next decade.”

Astronomers have already spotted hundreds of Jupiter-sized gas giants orbiting stars, but none have conditions suitable for Earth-type life.

However a rocky moon orbiting a gas giant could harbour life if it was in the parent star’s “habitable zone” – the region where temperatures are just right for liquid water.

“All of the gas giant planets in our solar system have rocky and icy moons,” said Dr Kaltenegger. “That raises the possibility that alien Jupiters will also have moons. Some of those may be Earth-sized and able to hold onto an atmosphere.”

A Pandora-type moon could be identified when its planet “transits” across the face of the parent star. If the moon has an atmosphere, this will absorb a tiny amount of light from the star, leaving a spectrographic fingerprint of its composition.

Dr Kaltenegger calculated that Alpha Centauri A, the star featured in Avatar, would provide an excellent target for astronomers hunting habitable moons.

Alpha Centauri is the closest star system to the Sun, being only 4.37 light years away. It consists of three stars, the largest being Alpha Centauri A, which is slightly brighter than the Sun.

“Alpha Centauri A is a bright, nearby star very similar to our Sun, so it gives us a strong signal,” said Dr Kaltenegger. “You would only need a handful of transits to find water, oxygen, carbon dioxide and methane on an Earth-like moon such as Pandora.

“If the Avatar movie is right in its vision, we could characterise that moon with JWST in the near future.”

She said small, dim red dwarf stars may provide the best evidence of habitable planets or moons. This is because the habitable zone for a red dwarf is closer to the star, which increases the likelihood of a transit as seen from the Earth. Red dwarfs are also the most common kind of star in our galaxy, the Milky Way.

A planet close enough to a red dwarf to be in its habitable zone may also be tidally “locked” by gravity so that the same face always points towards the star. This could be a problem for life, since one side of the planet would bake in constant sunlight, while the other would freeze in constant darkness.

An exomoon orbiting the planet, on the other hand, would have regular day-night cycles and moderate temperatures.

“Alien moons orbiting gas giant planets may be more likely to be habitable than tidally locked Earth-sized planets or super-Earths,” said Dr Kaltenegger. “We should certainly keep them in mind as we work toward the ultimate goal of finding alien life.”

Dr Kaltenegger’s research is published online in Astrophysical Journal Letters (http://www.iop.org/EJ/abstract/0004-637X/698/1/519)

__________

Full article: http://www.independent.co.uk/news/science/avatar-moons-may-become-a-science-fact-1846067.html

Read Full Post »

Solving a Tonal Mystery in Orbit Around Saturn

The Cassini spacecraft took this photo of Saturn’s moon Iapetus in September 2007.

Researchers have solved what may be the oldest mystery in planetary science: the two-tone surface of Saturn’s moon Iapetus.

The odd feature — the moon’s trailing side is about 10 times brighter than its leading side — has been a mystery since it was first observed by Giovanni Cassini in 1671. In two papers published online by Science, researchers have unraveled the mystery, using images and data from instruments aboard the spacecraft named for Cassini.

The studies confirm an earlier idea that dust, most likely from another of Saturn’s moons, falls on the leading side of Iapetus as it orbits the planet.

“It’s just like a motorcyclist, who only gets the flies on the leading side of the helmet rather than the trailing side,” said Tillmann Denk of the Free University of Berlin, an author with John R. Spencer of the Southwest Research Institute of one of the papers and lead author of the other.

But the pattern of the surface features — the dark area extends to the trailing side at the equator, for example — is not fully explained by the deposition dust. Rather, the researchers say, the reason has a lot to do with the moon’s rotation on its axis, which takes 80 earth days.

Such a slow rotation (“midday” lasts for a couple of weeks) allows the distant Sun to warm the dark dust-covered areas enough that water ice becomes vapor.

The vapor migrates elsewhere, freezing to ice again when it reaches colder areas. The areas where the ice was lost become darker, and those that gained ice become brighter.

Henry Fountain, New York Times

__________

Full article and photo: http://www.nytimes.com/2009/12/15/science/15obmoon.html

Read Full Post »

Water Found on Moon, Scientists Say

This artist’s rendering released by NASA shows the Lunar Crater Observation and Sensing Satellite as it crashed into the moon to test for the presence of water last month.

There is water on the Moon, scientists stated unequivocally on Friday.

“Indeed yes, we found water,” Anthony Colaprete, the principal investigator for NASA’s Lunar Crater Observation and Sensing Satellite, said in a news conference. “And we didn’t find just a little bit. We found a significant amount.”

The confirmation of scientists’ suspicions is welcome news to explorers who might set up home on the lunar surface and to scientists who hope that the water, in the form of ice accumulated over billions of years, holds a record of the solar system’s history.

The satellite, known as Lcross (pronounced L-cross), crashed into a crater near the Moon’s south pole a month ago. The 5,600-miles-per-hour impact carved out a hole 60 to 100 feet wide and kicked up at least 26 gallons of water.

“We got more than just a whiff,” Peter H. Schultz, a professor of geological sciences at Brown University and a co-investigator of the mission, said in a telephone interview. “We practically tasted it with the impact.”

For more than a decade, planetary scientists have seen tantalizing hints of water ice at the bottom of these cold craters where the sun never shines. The Lcross mission, intended to look for water, was made up of two pieces of an empty rocket stage to slam into the floor of Cabeus, a crater 60 miles wide and 2 miles deep, and a small spacecraft to measure what was kicked up.

For space enthusiasts who stayed up, or woke up early, to watch the impact on Oct. 9, the event was anticlimactic, even disappointing, as they failed to see the anticipated debris plume. Even some high-powered telescopes on Earth like the Palomar Observatory in California did not see anything.

The National Aeronautics and Space Administration later said that Lcross did indeed photograph a plume but that the live video stream was not properly attuned to pick out the details.

The water findings came through an analysis of the slight shifts in color after the impact, showing telltale signs of water molecules that had absorbed specific wavelengths of light. “We got good fits,” Dr. Colaprete said. “It was a unique fit.”

The scientists also saw colors of ultraviolet light associated with molecules of hydroxyl, consisting of one hydrogen and one oxygen, presumably water molecules that had been broken apart by the impact and then glowed like neon signs.

In addition, there were squiggles in the data that indicated other molecules, possibly carbon dioxide, sulfur dioxide, methane or more complex carbon-based molecules. “All of those are possibilities,” Dr. Colaprete said, “but we really need to do the work to see which ones work best.”

Remaining in perpetual darkness like other craters near the lunar poles, the bottom of Cabeus is a frigid minus 365 degrees Fahrenheit, cold enough that anything at the bottom of such craters never leaves. These craters are “really like the dusty attic of the solar system,” said Michael Wargo, the chief lunar scientist at NASA headquarters.

The Moon was once thought to be dry. Then came hints of ice in the polar craters. In September, scientists reported an unexpected finding that most of the surface, not just the polar regions, might be covered with a thin veneer of water.

The deposits in the lunar craters may be as informative about the Moon as ice cores from Earth’s polar regions are about the planet’s past climates. Scientists want to know the source and history of whatever water they find. It could have come from the impacts of comets, for instance, or from within the Moon.

“Now that we know that water is there, thanks to Lcross, we can begin in earnest to go to this next set of questions,” said Gregory T. Delory of the University of California, Berkeley.

Dr. Delory said the findings of Lcross and other spacecraft were “painting a really surprising new picture of the Moon; rather than a dead and unchanging world, it could be in fact a very dynamic and interesting one.”

Lunar ice, if bountiful, not only give future settlers something to drink, but could also be broken apart into oxygen and hydrogen. Both are valuable as rocket fuel, and the oxygen would also give astronauts air to breathe.

NASA’s current exploration plans call for a return of astronauts to the Moon by 2020, for the first visit since 1972. But a panel appointed in May recently concluded that trimmings of the agency’s budget made that goal impossible. One option presented to the Obama administration was to bypass Moon landings for now and focus on long-duration missions in deep space.

Even though the signs of water were clear and definitive, the Moon is far from wet. The Cabeus soil could still turn out to be drier than that in deserts on Earth. But Dr. Colaprete also said that he expected that the 26 gallons were a lower limit and that it was too early to estimate the concentration of water in the soil.

The scientists also do not know whether the information from Cabeus is representative of the state of other lunar craters.

Kenneth Chang, New York Times

__________

Full article and photo: http://www.nytimes.com/2009/11/14/science/14moon.html

Read Full Post »

Setting Sail Into Space, Propelled by Sunshine

DEEP-SPACE TRAVEL If the launching of LightSail-1 goes off according to plan next year, humans may soon be solar-sailing, as shown in this illustration.

Peter Pan would be so happy.

About a year from now, if all goes well, a box about the size of a loaf of bread will pop out of a rocket some 500 miles above the Earth. There in the vacuum it will unfurl four triangular sails as shiny as moonlight and only barely more substantial. Then it will slowly rise on a sunbeam and move across the stars.

LightSail-1, as it is dubbed, will not make it to Neverland. At best the device will sail a few hours and gain a few miles in altitude. But those hours will mark a milestone for a dream that is almost as old as the rocket age itself, and as romantic: to navigate the cosmos on winds of starlight the way sailors for thousands of years have navigated the ocean on the winds of the Earth.

“Sailing on light is the only technology that can someday take us to the stars,” said Louis Friedman, director of the Planetary Society, the worldwide organization of space enthusiasts.

Even as the National Aeronautics and Space Administration continues to flounder in a search for its future, Dr. Friedman announced Monday that the Planetary Society, with help from an anonymous donor, would be taking baby steps toward a future worthy of science fiction. Over the next three years, the society will build and fly a series of solar-sail spacecraft dubbed LightSails, first in orbit around the Earth and eventually into deeper space.

The voyages are an outgrowth of a long collaboration between the society and Cosmos Studios of Ithaca, N.Y., headed by Ann Druyan, a film producer and widow of the late astronomer and author Carl Sagan.

Sagan was a founder of the Planetary Society, in 1980, with Dr. Friedman and Bruce Murray, then director of the Jet Propulsion Laboratory. The announcement was made at the Hart Senate Office Building in Washington at a celebration of what would have been Sagan’s 75th birthday. He died in 1996.

Ms. Druyan, who has been chief fund-raiser for the society’s sailing projects, called the space sail “a Taj Mahal” for Sagan, who loved the notion and had embraced it as a symbol for the wise use of technology.

There is a long line of visionaries, stretching back to the Russian rocket pioneers Konstantin Tsiolkovsky and Fridrich Tsander and the author Arthur C. Clarke, who have supported this idea. “Sails are just a marvelous way of getting around the universe,” said Freeman Dyson, of the Institute for Advanced Study in Princeton, N.J., and a longtime student of the future, “but it takes a long time to imagine them becoming practical.”

The solar sail receives its driving force from the simple fact that light carries not just energy but also momentum — a story told by every comet tail, which consists of dust blown by sunlight from a comet’s core. The force on a solar sail is gentle, if not feeble, but unlike a rocket, which fires for a few minutes at most, it is constant. Over days and years a big enough sail, say a mile on a side, could reach speeds of hundreds of thousands of miles an hour, fast enough to traverse the solar system in 5 years. Riding the beam from a powerful laser, a sail could even make the journey to another star system in 100 years, that is to say, a human lifespan.

Whether humans could ever take these trips depends on just how starry-eyed one’s view of the future is.

Dr. Friedman said it would take too long and involve too much exposure to radiation to sail humans to a place like Mars. He said the only passengers on an interstellar voyage — even after 200 years of additional technological development — were likely to be robots or perhaps our genomes encoded on a chip, a consequence of the need to keep the craft light, like a giant cosmic kite.

In principle, a solar sail can do anything a regular sail can do, like tacking. Unlike other spacecraft, it can act as an antigravity machine, using solar pressure to balance the Sun’s gravity and thus hover anyplace in space.

And, of course, it does not have to carry tons of rocket fuel. As the writer and folk singer Jonathan Eberhart wrote in his song “A Solar Privateer”:

No cold LOX tanks or reactor banks, just Mylar by the mile.

No stormy blast to rattle the mast, a sober wind and true.

Just haul and tack and ball the jack like the waterlubbers do.

Those are visions for the long haul. “Think centuries or millennia, not decades,” said Dr. Dyson, who also said he approved of the Planetary Society project.

“We ought to be doing things that are romantic,” he said, adding that nobody knew yet how to build sails big and thin enough for serious travel. “You have to get equipment for unrolling them and stretching them — a big piece of engineering that’s not been done. But the joy of technology is that it’s unpredictable.”

At one time or another, many of NASA’s laboratories have studied solar sails. Scientists at the Jet Propulsion Laboratory even once investigated sending a solar sail to rendezvous and ride along with Halley’s Comet during its pass in 1986.

But efforts by the agency have dried up as it searches for dollars to keep the human spaceflight program going, said Donna Shirley, a retired J.P.L. engineer and former chairwoman of the NASA Institute for Advanced Concepts. Dr. Shirley said that the solar sail was feasible and that the only question was, “Do you want to spend some money?” Until the technology had been demonstrated, she said, no one would use it.

Japan continues to have a program, and test solar sails have been deployed from satellites or rockets, but no one has ever gotten as far as trying to sail them anywhere.

Dr. Friedman, who cut his teeth on the Halley’s Comet proposal, has long sought to weigh anchor in space. An effort by the Planetary Society and the Russian Academy of Sciences to launch a sail about 100 feet on a side, known as Cosmos-1, from a Russian missile submarine in June 2005 ended with what Ms. Druyan called “our beautiful spacecraft” at the bottom of the Barents Sea.

Ms. Druyan and Dr. Friedman were beating the bushes for money for a Cosmos-2, when NASA asked if the society wanted to take over a smaller project known as the Nanosail. These are only 18 feet on a side and designed to increase atmospheric drag and thus help satellites out of orbit.

And so LightSail was born. Its sail, adapted from the Nanosail project, is made of aluminized Mylar about one-quarter the thickness of a trash bag. The body of the spacecraft will consist of three miniature satellites known as CubeSats, four inches on a side, which were first developed by students at Stanford and now can be bought on the Web, among other places. One of the cubes will hold electronics and the other two will carry folded-up sails, Dr. Friedman said.

Assembled like blocks, the whole thing weighs less than five kilograms, or about 11 pounds. “The hardware is the smallest part,” Dr. Friedman said. “You can’t spend a lot on a five-kilogram system.”

The next break came when Dr. Friedman was talking about the LightSail to a group of potential donors. A man — “a very modest dear person,” in Ms. Druyan’s words — asked about the cost of the missions and then committed to paying for two of them, and perhaps a third, if all went well.

After the talk, the man, who does not wish his identity to be known, according to the society, came up and asked for the society’s bank routing number. Within days the money was in its bank account. The LightSail missions will be spread about a year apart, starting around the end of 2010, with the exact timing depending on what rockets are available. The idea, Dr. Friedman said, is to piggyback on the launching of a regular satellite. Various American and Russian rockets are all possibilities for a ride, he said.

Dr. Friedman said the first flight, LightSail-1, would be a success if the sail could be controlled for even a small part of an orbit and it showed any sign of being accelerated by sunlight. “For the first flight, anything measurable is great,” he said. In addition there will be an outrigger camera to capture what Ms. Druyan called “the Kitty Hawk moment.”

The next flight will feature a larger sail and will last several days, building up enough velocity to raise its orbit by tens or hundreds of miles, Dr. Friedman said.

For the third flight, Dr. Friedman and his colleagues intend to set sail out of Earth orbit with a package of scientific instruments to monitor the output of the Sun and provide early warning of magnetic storms that can disrupt power grids and even damage spacecraft. The plan is to set up camp at a point where the gravity of the Earth and Sun balance each other — called L1, about 900,000 miles from the Earth — a popular place for conventional scientific satellites. That, he acknowledges, will require a small rocket, like the attitude control jets on the shuttle, to move out of Earth orbit, perhaps frustrating to a purist.

But then again, most sailboats do have a motor for tooling around in the harbor, which is how Dr. Friedman describes being in Earth orbit. Because the direction of the Sun keeps changing, he said, you keep “tacking around in the harbor when what you want to do is get out on the ocean.”

The ocean, he said, awaits.

Dennis Overbye, New York Times

__________

Full article and photos: http://www.nytimes.com/2009/11/10/science/space/10solar.html?ref=science

Read Full Post »

Opening Up A Colorful Cosmic Jewel Box

The FORS1 instrument on the ESO Very Large Telescope (VLT) at ESO’s Paranal Observatory was used to take this exquisitely sharp close up view of the colorful Jewel Box cluster, NGC 4755. The telescope’s huge mirror allowed very short exposure times: just 2.6 seconds through a blue filter (B), 1.3 seconds through a yellow/green filter (V) and 1.3 seconds through a red filter (R). The field of view spans about seven arcminutes.

Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux.

The Kappa Crucis Cluster, also known as NGC 4755 or simply the “Jewel Box” is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking colour contrasts of its pale blue and orange stars seen through a telescope reminded Herschel of a piece of exotic jewellery.

Open clusters [1] such as NGC 4755 typically contain anything from a few to thousands of stars that are loosely bound together by gravity. Because the stars all formed together from the same cloud of gas and dust their ages and chemical makeup are similar, which makes them ideal laboratories for studying how stars evolve.

The position of the cluster amongst the rich star fields and dust clouds of the southern Milky Way is shown in the very wide field view generated from the Digitized Sky Survey 2 data. This image also includes one of the stars of the Southern Cross as well as part of the huge dark cloud of the Coal Sack [2].

A new image taken with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile shows the cluster and its rich surroundings in all their multicoloured glory. The large field of view of the WFI shows a vast number of stars. Many are located behind the dusty clouds of the Milky Way and therefore appear red [3].

The FORS1 instrument on the ESO Very Large Telescope (VLT) allows a much closer look at the cluster itself. The telescope’s huge mirror and exquisite image quality have resulted in a brand-new, very sharp view despite a total exposure time of just 5 seconds. This new image is one of the best ever taken of this cluster from the ground.

The Jewel Box may be visually colourful in images taken on Earth, but observing from space allows the NASA/ESA Hubble Space Telescope to capture light of shorter wavelengths than can not be seen by telescopes on the ground. This new Hubble image of the core of the cluster represents the first comprehensive far ultraviolet to near-infrared image of an open galactic cluster. It was created from images taken through seven filters, allowing viewers to see details never seen before. It was taken near the end of the long life of the Wide Field Planetary Camera 2 ― Hubble’s workhorse camera up until the recent Servicing Mission, when it was removed and brought back to Earth. Several very bright, pale blue supergiant stars, a solitary ruby-red supergiant and a variety of other brilliantly coloured stars are visible in the Hubble image, as well as many much fainter ones. The intriguing colours of many of the stars result from their differing intensities at different ultraviolet wavelengths.

The huge variety in brightness of the stars in the cluster exists because the brighter stars are 15 to 20 times the mass of the Sun, while the dimmest stars in the Hubble image are less than half the mass of the Sun. More massive stars shine much more brilliantly. They also age faster and make the transition to giant stars much more quickly than their faint, less-massive siblings.

The Jewel Box cluster is about 6400 light-years away and is approximately 16 million years old.

 Notes:

[1] Open, or galactic, star clusters are not to be confused with globular clusters ― huge balls of tens of thousands of ancient stars in orbit around our galaxy and others. It seems that most stars, including our Sun, formed in open clusters.

[2] The Coal Sack is a dark nebula in the Southern Hemisphere, near the Southern Cross, that can be seen with the unaided eye. A dark nebula is not the complete absence of light, but an interstellar cloud of thick dust that obscures most background light in the visible.

[3] If the light from a distant star passes through dust clouds in space the blue light is scattered and absorbed more than the red. As a result the starlight looks redder when it arrives on Earth. The same effect creates the glorious red colours of terrestrial sunsets.

__________

Full article and photo: http://www.sciencedaily.com/releases/2009/10/091029102425.htm

Read Full Post »

Physicist Makes New High-resolution Panorama Of Milky Way

Full sky panorama of the Milky Way

Cobbling together 3000 individual photographs, a physicist has made a new high-resolution panoramic image of the full night sky, with the Milky Way galaxy as its centerpiece. Axel Mellinger, a professor at Central Michigan University, describes the process of making the panorama in the November issue of Publications of the Astronomical Society of the Pacific.

“This panorama image shows stars 1000 times fainter than the human eye can see, as well as hundreds of galaxies, star clusters and nebulae,” Mellinger said. Its high resolution makes the panorama useful for both educational and scientific purposes, he says.

Mellinger spent 22 months and traveled over 26,000 miles to take digital photographs at dark sky locations in South Africa, Texas and Michigan. After the photographs were taken, “the real work started,” Mellinger said.

Simply cutting and pasting the images together into one big picture would not work. Each photograph is a two-dimensional projection of the celestial sphere. As such, each one contains distortions, in much the same way that flat maps of the round Earth are distorted. In order for the images to fit together seamlessly, those distortions had to be accounted for. To do that, Mellinger used a mathematical model — and hundreds of hours in front of a computer.

Another problem Mellinger had to deal with was the differing background light in each photograph.

“Due to artificial light pollution, natural air glow, as well as sunlight scattered by dust in our solar system, it is virtually impossible to take a wide-field astronomical photograph that has a perfectly uniform background,” Mellinger said.

To fix this, Mellinger used data from the Pioneer 10 and 11 space probes. The data allowed him to distinguish star light from unwanted background light. He could then edit out the varying background light in each photograph. That way they would fit together without looking patchy.

The result is an image of our home galaxy that no star-gazer could ever see from a single spot on earth. Mellinger plans to make the giant 648 megapixel image available to planetariums around the world.

An interactive version of the picture can viewed on Mellinger’s website.

__________

Full article and photo: http://www.sciencedaily.com/releases/2009/10/091028112758.htm

Read Full Post »

Space hopper

Lunar landers

A prize for a moon lander will be won this month

Boing!

IF PEOPLE are to explore the moon again they will need ways of travelling across the lunar surface and also of digging holes in it. But because America’s space agency, NASA, spends most of its money on the space station and the shuttle, little is left over for the innovative research and development in areas such as these that many people think it should be carrying out in the first place.

The answer NASA has come up with is something it calls its Centennial Challenges. These are a series of prizes for technological achievement in areas such as beamed power, lunar landers and the extraction of oxygen from lunar regolith (the crushed rock that passes for soil on the moon). The point is to spur technological development using the twin lures of hard cash and the kudos of being officially recognised as cleverer than your peers.

On October 18th, therefore, 19 robots competed in the Regolith Excavation Challenge. The three teams behind the winning machines claimed a total of $750,000.

To win, a robot had to excavate 150kg (330lb) of simulated lunar soil and move it into a container in less than half an hour. Worthy and important, of course, but a sideshow to another of the events that is taking place this month. This is the Northrop Grumman Lunar Lander Challenge. And it looks as if, by the time festivities are over on October 31st, much of the $2m prize fund for this particular contest will have been won, too.

Companies that have competed in the lunar lander challenge so far include Armadillo Aerospace, TrueZer0, Masten Space Systems, Unreasonable Rocket and BonNova. Against a tight timeline, the teams must prepare their vehicles to make vertical take-offs, controlled flights and successful landings—and then hop back home again. The easier level of the challenge requires flights of 90 seconds and a landing on a small, flat circular pad. The more difficult second level requires a flight of 180 seconds followed by a landing on simulated lunar terrain, complete with rocks and craters.

Last year Armadillo Aerospace (based in Rockwall, Texas) won first place and $350,000 in the easy category. Earlier this month Masten Space Systems (of Mojave, California) replicated Armadillo’s efforts with a lander called Xombie, qualifying for the second prize ($150,000). Both companies, with the other entrants, are now hoping to win the level-two award. Armadillo has already made a qualifying flight and, if none of the other teams can match or beat that by the end of the month, it will walk away with the top prize of $1m.

The lunar lander challenge has been running since 2006 and has provided ample demonstration of the effect, long known in technology-prize circles, that the money and effort invested in winning far exceed the financial value of the prize itself. The promise of prestige loosens the purse strings of both wealthy individuals, such as John Carmack, the computer-game entrepreneur behind Armadillo, as competitors, and large companies, such as Northrop Grumman, as sponsors.

The lunar lander challenge is good news for NASA, because it can now count on groups of potential suppliers and experienced engineers to build any future moon lander. NASA will be hoping for more good news for its moon programme on October 27th, when its experimental Ares 1-X rocket, costing $455m, should make its first test flight from Cape Canaveral, in Florida. Against this backdrop, however, is a struggle for cash, and the new administration has already indicated that it has not got the money to pay for a return to the moon with prizes. So far, attempts to spur the private sector to travel to the moon have not been successful either, probably because not enough money is being offered.

Nonetheless, in the right context, and with the right design, prizes can work. Their other advantage is that—in contrast to the fat government contracts on which much of the aerospace industry thrives—the money is handed out only when the goals are achieved. That is a lesson in incentives that governments would do well to remember.

__________
Full article and photo: http://www.economist.com/sciencetechnology/displayStory.cfm?story_id=14698371&source=hptextfeature

Read Full Post »

Scientists announce planet bounty

_____

Artist’s impression: Astronomers are finding smaller and smaller planet
 

Astronomers have announced a haul of planets found beyond our Solar System.

The 32 “exoplanets” ranged in size from five times the mass of Earth to 5-10 times the mass of Jupiter, the researchers said.

They were found using a very sensitive instrument on a 3.6m telescope at the European Southern Observatory’s La Silla facility in Chile.

The discovery is exciting because it suggests that low-mass planets could be numerous in our galaxy.

“From [our] results, we know now that at least 40% of solar-type stars have low-mass planets. This is really important because it means that low-mass planets are everywhere, basically,” explained Stephane Udry from Geneva University, Switzerland.

“What’s very interesting is that models are predicting them, and we are finding them; and furthermore the models are predicting even more lower-mass planets like the Earth.”

Size selection

The discovery now takes the number of known exoplanets – planets outside our Solar System – to more than 400.

These have been identified using a range of astronomical techniques and telescopes, but this latest group was spotted as a result of observations made with the Harps spectrometer at La Silla.

The High Accuracy Radial Velocity Planet Searcher instrument employs what is sometimes called the “wobble technique”.

This is an indirect method of detection that infers the existence of orbiting planets from the way their gravity makes a parent star appear to twitch in its motion across the sky.

Astronomy is working right at the limits of the current technology capable of detecting exoplanets and most of those found so far are Jupiter-scale and bigger.

Harps, however, has focussed its efforts on small, relatively cool stars – so-called M-class stars – in the hope of finding low-mass planets, ones most likely to resemble the rocky planets in our own Solar System.

Of the 28 planets known with masses below 20 Earth-masses, Harps has now identified 24 of them – and six of those are in the newly announced group.

“We have two candidates at five Earth-masses and two at six Earth-masses,” Professor Udry told BBC News.

Combined approach

Harps has previously identified an object which is only twice as massive as the Earth (announced in April).

Scientists are confident this planet harbours no life, though, because it orbits so close to its parent star that surface temperatures would be scorching.

In revealing the new collection of planets on Monday, the Harps team-members said they expected to confirm the existence of another batch, similar in number, during the coming six months.

The ultimate goal is to find a rocky planet in a star’s “habitable zone”, an orbit where temperatures are in a range that would support the presence of liquid water.

Scientists believe the introduction of newer, more sensitive technologies will allow them to identify such an object within just a few years from now.

The US space agency (Nasa) recently launched its Kepler telescope.

This hopes to find Earth-size planets by looking for the tiny dip in light coming from a star as an object crosses its face as viewed from Earth.

To properly characterise a planet, different observing techniques are required. The Kepler “transit” method reveals the diameter of an object, but a Harps-like measurement is needed to resolve the mass.

__________

Full article and photo: http://news.bbc.co.uk/2/hi/science/nature/8314581.stm

Read Full Post »

Galactic Magnetic Fields May Control Boundaries Of Our Solar System

The first all-sky maps developed by NASA’s Interstellar Boundary Explorer (IBEX) spacecraft, the initial mission to examine the global interactions occurring at the edge of the solar system, suggest that the galactic magnetic fields had a far greater impact on Earth’s history than previously conceived, and the future of our planet and others may depend, in part, on how the galactic magnetic fields change with time.

“The IBEX results are truly remarkable, with emissions not resembling any of the current theories or models of this never-before-seen region,” says Dr. David J. McComas, IBEX principal investigator and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute. “We expected to see small, gradual spatial variations at the interstellar boundary, some 10 billion miles away. However, IBEX is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky.”

A “solar wind” of charged particles continuously travels at supersonic speeds away from the Sun in all directions. This solar wind inflates a giant bubble in interstellar space called the heliosphere — the region of space dominated by the Sun’s influence in which the Earth and other planets reside. As the solar wind travels outward, it sweeps up newly formed “pickup ions,” which arise from the ionization of neutral particles drifting in from interstellar space. IBEX measures energetic neutral atoms (ENAs) traveling at speeds of roughly half a million to two and a half million miles per hour. These ENAs are produced from the solar wind and pick-up ions in the boundary region between the heliosphere and the local interstellar medium.

The IBEX mission just completed the first global maps of these protective layers called the heliosphere through a new technique that uses neutral atoms like light to image the interactions between electrically charged and neutral atoms at the distant reaches of our Sun’s influence, far beyond the most distant planets. It is here that the solar wind, which continually emanates from the Sun at millions of miles per hour, slams into the magnetized medium of charged particles, atoms and dust that pervades the galaxy and is diverted around the system. The interaction between the solar wind and the medium of our galaxy creates a complex host of interactions, which has long fascinated scientists, and is thought to shield the majority of harmful galactic radiation that reaches Earth and fills the solar system.

“The magnetic fields of our galaxy may change the protective layers of our solar system that regulate the entry of galactic radiation, which affects Earth and poses hazards to astronauts,” says Nathan Schwadron of Boston University’s Center for Space Physics and the lead for the IBEX Science Operations Center at BU.

Each six months, the IBEX mission, which was launched on October 18, 2008, completes its global maps of the heliosphere. The first IBEX maps are strikingly different than any of the predictions, which are now forcing scientists to reconsider their basic assumptions of how the heliosphere is created.

“The most striking feature is the ribbon that appears to be controlled by the magnetic field of our galaxy,” says Schwadron.

Although scientists knew that their models would be tested by the IBEX measurements, the existence of the ribbon is “remarkable” says Geoffrey Crew, a Research Scientist at MIT and the Software Design Lead for IBEX. “It suggests that the galactic magnetic fields are much stronger and exert far greater stresses on the heliosphere than we previously believed.”

The discovery has scientists thinking carefully about how different the heliosphere could be than they expected.

“It was really surprising that the models did not generate features at all like the ribbon we observed,” says Christina Prested, a BU graduate student working on IBEX. “Understanding the ribbon in detail will require new insights into the inner workings of the interactions at the edge of our Sun’s influence in the galaxy.”

Adds Schwadron,”Any changes to our understanding of the heliosphere will also affect how we understand the astrospheres that surround other stars. The harmful radiation that leaks into the solar system from the heliosphere is present throughout the galaxy and the existence of astrospheres may be important for understanding the habitability of planets surrounding other stars.”

IBEX is the latest in NASA’s series of low-cost, rapidly developed Small Explorers space missions. Southwest Research Institute in San Antonio, Texas, leads and developed the mission with a team of national and international partners. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the Explorers Program for NASA’s Science Mission Directorate in Washington.

__________

Full article: http://www.sciencedaily.com/releases/2009/10/091016112630.htm

Read Full Post »

In Test of Water on Moon, Craft Hits Bull’s-Eye

This artist’s rendering released by NASA on Friday shows the Lunar Crater Observation and Sensing Satellite as it crashes into the moon to test for the presence of water.

Scientists who slammed a bus-size projectile into the Moon on Friday, hitting exactly the spot they were aiming for, say it will take weeks to figure out what they did, and did not, see.

More than 230,000 miles from Earth, the Lunar Crater Observation and Sensing Satellite hit a bull’s-eye — two, actually — on the Moon. But the initial images at least, both from the spacecraft and telescopes on Earth, failed to capture expected plumes of debris rising out of the impacts.

At 4:31 a.m. Pacific time (7:31 a.m. Eastern time), one piece of Lcross slammed into the bottom of a crater, excavating hundreds of tons of the Moon. Trailing four minutes behind, a second piece sent its observations back to Earth before it also slammed into the same crater.

The absence of a visible plume disappointed the hundreds of enthusiasts who braved a chilly evening outside at the NASA Ames Research Center here, which operated the spacecraft, to watch the live images transmitted from the spacecraft.

But Anthony Colaprete, the mission’s principal investigator, was ecstatic. “We got the data we need to address the questions,” he said at a news conference.

Of greatest interest is whether there is water ice hidden in the crater’s perpetual darkness and frigidness. The data could play into the debate over where NASA’s human spaceflight program should aim next, whether to return to the Moon or head elsewhere in the solar system neighborhood. The presence of large significant amounts of water could make it easier to set up future settlements with the ice providing water and oxygen.

Data from NASA’s Lunar Reconnaissance Orbiter has already confirmed the presence of hydrogen deep within permanently shadowed craters near the Moon’s poles, and hydrogen is most likely in the form of water.

Lcross (pronounced L-cross) is a $79 million companion mission to the Lunar Reconnaissance Orbiter, sharing the same rocket into space in June. The mission designers took advantage of what would have otherwise been space junk — the rocket’s two-ton, second stage — and turned it into a projectile to hit the Moon, shepherded by a car-size spacecraft.

While the orbiter entered orbit around the Moon, Lcross swung into a wide polar orbit around the Earth that, by design, would intersect with the Moon’s path four months later at 5,600 miles per hour, or twice the speed of a bullet.

The target of Lcross was Cabeus crater, about 60 miles wide near the south pole.

Dr. Colaprete said the Lcross spacecraft captured a flash of light as the upper stage hit the bottom of Cabeus and then captured a thermal image of the resulting crater, about 60 to 65 feet wide, close to what had been predicted.

What was missing was the plume of debris that was knocked out by the impact. “We saw a crater. We saw a flash,” Dr. Colaprete said. “Something had to happen in between.”

Ground-based telescopes that had been pointed to that crater at the bottom of the Moon also failed to spot the theatrics, at least at first glance of their images.

“As far as I can tell from our quick processing, we did not see any plume,” said William C. Keel, a professor of astronomy at the University of Alabama who was operating a telescope at the Kitt Peak National Observatory in Arizona.

If the expended rocket stage hit a rocky area or a slope, the debris may not have been tossed high enough to reach sunlight and thus not have been seen.

But Lcross’s spectrometers — instruments that break down light into wavelengths and detect subtle changes, perhaps from vapor or fine particles not visible to the eye — did observe changes before and after the impact. Dr. Colaprete said the spectrometer data could identify the water and other molecules. “When I saw actually the spectra, I was like, “We got something,’ ” he said.

The analysis will take at least a few days and maybe weeks.

“We’re going to take our time,” Dr. Colaprete said, “and build up a case for water and the ejecta, if it’s there or the case against it if it’s not there.”

While Lcross itself had the best view of the first impact, a host of telescopes in space and on Earth, including the Hubble Space Telescope and the Keck telescope in Hawaii, were also gazing at the Moon. The other telescopes also tried to observe the second impact of the Lcross spacecraft.

Several hundred people spent a chilly night on a grassy lawn at the Ames Research Center. They listened to Charlie Duke, one of the Apollo 16 astronauts, and watched three space-themed films — “Fly Me to the Moon,” “The Dish” and “October Sky” — projected on a 40-foot screen.

Then they watched the same NASA coverage of the mission, streamed over the Internet, that they could have watched at home.

“It’s adventurous and nerdy at the same time,” said Karin Atkins of Sunnyvale, Calif., one of those pulling an outdoors all-nighter.

Kenneth Chang, New York Times

__________
Full article and photos: http://www.nytimes.com/2009/10/10/science/space/10moon.html

Read Full Post »

Canadian Astronomers Capture Spectacular Meteor Footage And Images

Composite all-sky camera image of the end of the fireball as seen from Hamilton (Camera #3, McMaster).

Astronomers from The University of Western Ontario have released footage of a meteor that was approximately 100 times brighter than a full moon. The meteor lit up the skies of southern Ontario two weeks ago and Western astronomers are now hoping to enlist the help of local residents in recovering one or more possible meteorites that may have crashed in the area of Grimsby, Ontario.

The Physics and Astronomy Department at Western has a network of all-sky cameras in southern Ontario that scan the atmosphere monitoring for meteors. Associate Professor Peter Brown, who specializes in the study of meteors and meteorites, says that on Friday, September 25 at 9:03 p.m. EST seven all-sky cameras of Western’s Southern Ontario Meteor Network (SOMN) recorded a brilliant fireball in the evening sky over the west end of Lake Ontario.

Brown along with Phil McCausland, a postdoctoral fellow at Western’s Centre for Planetary Science & Exploration, are now working to get the word out amongst interested people who may be willing to see if they can spot any fallen meteorites.

“This particular meteorite fall, if any are found, is very important because its arrival was so well recorded. We have good camera records as well as radar and infrasound detections of the event, so that it will be possible to determine its orbit prior to collision with the Earth and to determine the energy of the fireball event,” says McCausland. “We can also figure out where it came from and how it got here, which is rare. In all of history, only about a dozen meteorite falls have that kind of record.”

The fireball was first detected by Western’s camera systems at an altitude of 100 km over Guelph moving southeastwards at 20.8 km/s. The meteoroid was initially the size of a child’s tricycle.

Analysis of the all-sky camera records as well as data from Western’s meteor radar and infrasound equipment indicates that this bright fireball was large enough to have dropped meteorites in a region south of Grimsby on the Niagara Peninsula, providing masses that may total as much as several kilograms.

Researchers at Western are interested in hearing from anyone within 10 km of Grimsby who may have witnessed or recorded this event, seen or heard unusual events at the time, or who may have found possible fragments of the freshly fallen meteorite.

According to McCausland, meteorites are of great scientific value. He also points out that in Canada meteorites belong to the owner of the land upon which they are discovered. If individuals intend to search they should, in all cases, obtain the permission of the land owner before searching on private land.

Meteorites may best be recognized by their dark and scalloped exterior, and are usually denser than normal rock and will often attract a fridge magnet due to their metal content. In this fall, meteorites may be found in a small hole produced by their dropping into soil. Meteorites are not dangerous, but any recovered meteorites should be placed in a clean plastic bag or container and be handled as little as possible to preserve their scientific information.

For video footage, still images and site maps, please visit http://aquarid.physics.uwo.ca/research/fireball/events/25sept2009

__________

Full article and photo: http://www.sciencedaily.com/releases/2009/10/091007124411.htm

Read Full Post »

Seti: The hunt for ET

Scientists have been searching for aliens for 50 years, scanning the skies with an ever-more sophisticated array of radio telescopes and computers. Known as Seti, the search marks its half-century this month. Jennifer Armstrong and Andrew Johnson examine its close – and not so close – encounters.

Scientists have been searching for aliens for 50 years.

1. Seti stands for the Search for ExtraTerrestrial Intelligence.

 2. If intelligent aliens are out there, Dr Seth Shostak, the Seti Institute’s senior astronomer, believes they will be “thinking machines”. He believes a highly advanced species will be several centuries ahead of us in technological development.

3. Professor Duncan Forgan, an astronomer from Edinburgh University, estimates that between 360 and 38,000 life forms capable of interstellar communications have evolved at some point in the history of our galaxy.

4. In April 2006, Dr Shostak predicted we would find evidence of extraterrestrial life between 2020 and 2025. He believes the best way of bringing them up to speed with the human race is to send them the contents of the internet.

5. So far, no alien signals have been heard, however.

6. It was a September 1959 article in the journal Nature that persuaded the scientific community that, despite the unlikely aliens found in the era’s Cold War-inspired UFO films, alien intelligence was more likely than not, so kick-starting the Seti project.

7. The search proper began in 1960, however, with “Project Ozma” at the Green Bank radio telescope in West Virginia, America, directed by a Harvard graduate, Frank Drake.

8. Project Ozma was named after the queen of L Frank Baum’s fictional land of Oz, a place which is “very far away, difficult to reach, and populated by strange and exotic beings”.

9. The Microsoft founder Paul Allen is funding 42 radio antennae – the Allen Telescope Array in California – at a cost of £16m for the Seti project. It powered up this month.

10. When complete, the Allen Telescope Array will have 350 antenna dishes, each six metres in diameter.

11. At the moment, scientists scavenge time on the world’s biggest telescopes to hunt for signals. One of the most significant is the Arecibo Observatory radio telescope in Puerto Rico, made famous by Pierce Brosnan in the final sequence of the James Bond film Golden Eye. It’s the world’s biggest with a 305m diameter.

12. The most promising radio signal found to date, SHGb02+14a, was detected in 2003 at Arecibo. It was found on three occasions but emanates from between the constellations of Pisces and Aries where there are no stars. It is also a very weak signal. Scientists think it may have been due to an astrological phenomenon or a computer glitch.

13. A set of quickly pulsing signals known as LGM1 (Little Green Men) caused great excitement in 1967. It turned out that they were from a previously unknown class of super-dense rotating neutron stars now known as pulsars. The discovery won Tony Hewish, emeritus professor of radio astronomy at Cambridge University, a Nobel prize.

14. While radio telescopes on Earth are tuned into frequencies that scientists believe are the most likely to be used by intelligent life, there have been many attempts to contact aliens by sending signals and objects from Earth to likely-looking stars.

15. In 1974, astronomers sent crude pictures of humans, our DNA and our solar system to the star cluster M13, which is 21,000 light years away and contains a third of a million stars.

16. In 2001 a “reply” to the 1974 message was found in Hampshire in the form of a crop circle, featuring crude pictures of an alien, modified DNA and an improbable solar system. It is believed to be a hoax.

17. Nasa’s attempt to communicate with aliens by playing a Beatles track in February 2008 caused consternation. Some scientists pointed out that making a highly advanced race, which might have exhausted all the resources on their planet, aware of our existence might not be the most sensible thing to do.

18. Now an international agreement is in place preventing any reply to an extraterrestrial signal unless there is agreement that it’s a good idea.

19. However, if Einstein’s theory is correct that it is impossible to travel faster than the speed of light, there is no need to worry. It would take extraterrestrial life-forms millennia to reach us, unless they had the technology to cut corners in space by travelling through highly theoretical tunnels called wormholes. “You’re not going to see them in person, I think,” Dr Shostak said. “To go from here to the nearest star is a project requiring a 100,000-year trip. And that’s longer than you’re going to want to sit there eating airline food.”

20. But maybe they do have wormhole technology. See No 2.

21. The nearest stars likely to have planets are three parsecs away (one parsec equals 3.26 light years, or 19 million million miles) so even if a common language were found, it would take a century to communicate.

22. Seti hit the headlines in 1977 when a volunteer found a strong signal and wrote “Wow!” in the margin of a printout. The “Wow! Signal”, as it came to be known, was never found again despite repeated attempts.

23. Frank Drake’s Ozma project was originally kept secret as the observatory was government-funded and nobody wanted to let Congress know they were looking for aliens.

24. Nevertheless, Congress pulled the plug in 1993. The project is now funded by private donations.

25. Five million people have joined a scheme organised by the University of California in 1999 in which home computers help sift the millions of Seti readings during their “downtime” after a special screensaver is downloaded. SETI@home is the world’s largest supercomputer.

26. SETI@home can do tens to hundreds of billions of operations per second.

27. There are now lots of group-computing projects using the same software as SETI@home, from decoding enigma messages sent in the Second World War to predicting future climates or helping to find a cure for Aids.

28. Searches for other-worldly intelligence also involve looking for signals aliens may have sent us using light waves or infrared as well as radio waves.

29. The Drake equation (N = N* fp ne fl fi fc fL) was created by Frank Drake in 1961 to work out how many intelligent civilisations there may be in our galaxy. The values stand for things such as the number of stars and estimated number of planets. The answer varies from 2.31 to 1,000, as many of the values rely on guesswork.

30. Gene Roddenberry used the equation to justify the number of inhabited planets discovered by the crew of the Starship Enterprise in Star Trek.

31. Scientists admit, however, that aliens may already have tried to contact us with a form of communication completely unknown to us – a bit like trying to make contact with a lost tribe in Borneo using TV signals.

32. In 1950, Italian Nobel laureate and nuclear scientist Enrico Fermi stated the Fermi paradox: there’s a high probability of alien life but we haven’t detected any yet.

33. In the mid-1990s, Seti scientists thought they were on to something when they picked up a signal every evening at 7pm. It turned out to be from a microwave oven used by technicians in the cellar at the Parkes Observatory in Australia. There is now a note on the microwave asking people not to use it while Seti is active.

34. Other false calls have included signals from electronic garage doors, jet airliners, radios, televisions and even the Pioneer space craft. “We found intelligent life,” said Richard Davis, a radio astronomer at Jodrell Bank in Cheshire, “but it was us.”

35. The privately funded Seti Institute in California has an annual budget of $7m. It employs 130 staff and was founded 25 years ago in November.

36. The MoD recorded 394 UFO sightings in the UK in the first eight months of this year.

37. In 1996 only six exoplanets – those outside our solar system – had been found. Now nearly 400 have been discovered. Although none are Earth-like, scientists believe it is just a matter of time before one shows up.

38. Which is why Nasa launched the Kepler telescope in March. It will survey 100,000 Sun-like stars over the next four years, looking for Earth-like planets in the “Goldilocks Zone” – a distance from the Sun that is not too hot and not too cold.

39. Some think early flying saucer stories originated from spottings of experimental Nazi aircraft.

40. In June this year, Seti upgraded its Serendip (Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations) programme at Arecibo. The first programme listened to 100 channels simultaneously, the new programme can track more than two billion.

41. ET and Close Encounters director Steven Spielberg has been obsessed with the search for life outside our planet since childhood and donates money to Seti.

42. llie Arroway, Jodie Foster’s character in the film Contact, finds aliens using the same methods as a Seti radio-wave analysing programme Project Phoenix based in Australia.

43. Those hopeful of so-called “exo-biology” have been encouraged by recent discoveries of the building blocks of life floating around in space. Radio telescopes have picked up the chemical signatures of 150 molecules in interstellar space, including sugar, alcohol and amino acids.

44. The twin Voyager space probes, launched in 1977, carried gold discs containing information about Earth, including recordings of greetings in 54 different human languages, humpback whale song, 117 pictures of Earth and a collection of sounds including music from Mozart to Louis Armstrong. The discs were put together by the Seti advocate Carl Sagan at the request of Nasa. It will be 40,000 years before the discs get anywhere near another planetary system.

45. If aliens do find them, they will need to locate an old vinyl record player. Fortunately, there are instructions and a stylus on the spaceship.

46. In the 1820s the German mathematician Carl Friedrich Gauss, below, tried to contact aliens by reflecting sunlight towards planets. He also wanted to cut a giant triangle into the Siberian forest and plant wheat inside to show a geometric object visible from the Moon.

47. Around the same time, the Austrian mathematician Joseph Johann von Littrow proposed digging a circular canal in the Sahara 20 miles in diameter, filling it with paraffin and setting it on fire, thus alerting alien species to our existence.

48. Charles Cros, a French poet and inventor, thought spots of light on Mars and Venus were indicators of civilisations. He tried to convince the French government to build a giant mirror to communicate with the aliens. The lights he saw were probably noctilucent clouds (clouds so high they reflect sunlight at night); the mirror was almost certainly impossible to build.

49. Japan has prepared guidelines on how to handle aliens if they land and a strategy to defend the country from alien attack.

50. Early alien hunters at the 1960 conference at Green Bank, West Virginia, which established Seti as a scientific discipline, called themselves the Order of the Dolphin in honour of John Lilly, who had recently concluded that dolphins were intelligent and pioneered attempts to communicate with them.

__________

Full article and photo: http://www.independent.co.uk/news/science/seti-the-hunt-for-et-1793984.html

Read Full Post »

Naming the sky

The true story of one man’s quest to give George Plimpton a permanent presence in orbit

There’s something special about naming a celestial body, putting your thumbprint in the heavens up there with Jupiter and Mars and the Horsehead Nebula. The idea speaks to our desire for immortality–attaching a name to something that, if not quite eternal, will last far longer than anyone will be around to remember.

The world of commerce has figured this out, of course. Various services have arisen that claim to put your name on a star for a fee. Unfortunately, as nice as it sounds, these names don’t count: You pay your money and get a certificate, but it isn’t recognized by the only organization that actually matters, the International Astronomical Union.

So what if you really do want to name a piece of the sky? Is there a way to name a newly discovered star, or planet, or comet–maybe not after yourself, but maybe after someone you admire?

The answer, as it turns out, is yes, although it requires navigating some celestial red tape, and a fair amount of luck. I discovered this for myself when I set out to honor a distinguished American author–specifically, George Plimpton–by attaching his name to an asteroid. The journey took me to some interesting places: distant realms where science and humanities intersect, where the present hangs its hat on eternity, and where there’s a rock named Qwerty orbiting the sun.

In 2006, the big news in astronomy was that Pluto got demoted from planet to ”dwarf planet.” While everyone else was fretting about what this meant for the solar system, my attention was elsewhere: on the object that got Pluto downgraded. Tentatively it was called Xena, officially it became Eris, and I wanted to know how this object, or anything else celestial, was named. If I could figure that out, maybe I could name something in space as well.

It didn’t take me long before I encountered my first hard truth: naming a star was out of the question. No one names stars anymore. A new star, when it’s discovered, just gets tagged with a dull collection of letters and numbers. There are hundreds of millions of stars, and astronomers need a systematic way to find them, so they long ago stopped giving them individual names.

If you discover a comet, however, things are different. It’s automatically named after you. For example, comets Hyakutake, McNaught, and Hale-Bopp were discovered by (respectively) Messrs. Hyakutake, McNaught, Hale, and Bopp. But I wasn’t likely to discover a comet.

When it came to other extraterrestrial objects–moons, asteroids, or even craters–the rules started to get a lot more exciting. The extent of literary knowledge required to fully appreciate the names in our solar system is staggering. So-called trans-Neptunian objects, the ones beyond the eighth planet, must be named for gods of the underworld or gods related to creation (hello, Pluto). The moons of Uranus must be named after characters from Shakespeare or Alexander Pope. Out among the moons of Jupiter, Celtic gods bump up against characters from Dante’s Inferno. Features on the surface of Phobos, one of Mars’s moons, are named after people and places from ”Gulliver’s Travels.” The features of Phoebe, a moon of Saturn, are graced with names from the Argonautica, the tale of Jason and the Argonauts.

It’s a terrific blend of classics out there, a realm where King Arthur meets Hercules, where astronomers have let their off-kilter imaginations run free. As the writer Clive Thompson astutely noted on his blog, if these astronomers weren’t doing science, ”they’d be out in California painting unicorns on the sides of vans.”

Nowhere is this more evident than in the names of asteroids, or minor planets. These small rocky objects orbiting the sun are generally found in the asteroid belt between Mars and Jupiter. Some of them are governed by strict naming rules–those that orbit in concert with Jupiter, for example, must be named after warriors from the Trojan War. But assuming you discover an asteroid that has nothing particularly special about it, you can name it whatever you like.

And suddenly, any restraint on astronomers’ whims truly vanishes. There is a whole group of asteroids named after rock stars. Each member of Rush has a minor planet. Fantasia, Hammurabi, and Jerrylewis are all out there. While Goldfinger is not named after the Bond film (it’s named after an astronomer), Vespa is named after the motor scooter. Here is where we find the asteroid named Qwerty, and even an asteroid named ASCII.

If I was going to get to name something, it seemed, it was going to be an asteroid. Unfortunately, I couldn’t claim discoverer’s rights. But after a bit of reading, I found a little-known loophole: If an asteroid has not been named for 10 years since its discovery, it’s up for grabs. The name still has to conform to a few rules (it can’t be of a commercial nature, for example) and be cleared by the 15-member Committee on Small-Body Nomenclature that is part of the IAU. But suddenly, the potential for placing a name into the heavens seemed a possibility, however slight.

It turns out that there are actually many such unnamed asteroids that have lain fallow. Since asteroids can be discovered automatically using computational techniques, there are far more asteroids discovered than have been given names. For example, Spacewatch is a project designed to spot asteroids that might collide with Earth, and has discovered many new minor planets as part of its process.

So, after some looking, I found an asteroid that had been unnamed since being discovered in the early 1990s. But what should I name it? Well, the answer was clear.

I hadn’t always been aware of George Plimpton. In fact, my introduction to George didn’t come until a few months after his death, in the form of a Wall Street Journal crossword puzzle. The clues were an unbelievable litany: ”Magazine edited by 117-Across from its inception”; ”Maestro under whose baton 117-Across once played triangle”; ”Football team for which 117-Across briefly played quarterback”; ”TV series in which 117-Across once appeared as a professor.”

Who was this 117-Across? I was captivated that one person could do so much. George Plimpton, longtime editor of the Paris Review, was the consummate amateur. He would throw himself in the ring with the pros (once literally into the ring, with a light heavyweight boxing champ), handle himself with unmatched poise and enthusiasm even while being occasionally humiliated, and then write about it.

So naming an asteroid after him seemed perfect: As George Plimpton had done everything else under the sun, it was fitting that he would finally get to do the one thing he never tried his hand at–orbit. And if it worked, my whole amateur asteroid-naming attempt, trying to squeeze in briefly alongside the professionals, would be quintessentially Plimptonian.

So this was my moment. Following the rules outlined by the Minor Planet Center, I submitted a carefully formatted citation for why the minor planet I had found should be named Plimpton.

And then I didn’t hear anything back.

What would George do? He would strap on his helmet and charge right in. I contacted the head of the Minor Planet Center to see what had happened. He informed me that they generally receive so many names from the discoverers themselves that they rarely find time to consider names for previously discovered asteroids. He then asked me if there was a reason I wanted to name that particular asteroid after Plimpton.

Not that particular one, I replied, but then I suggested another unnamed asteroid that had been discovered on George Plimpton’s birthday. And then I got a wonderful e-mail: The head of the center suggested a better asteroid–one with a designation that included Plimpton’s initials! I now had him on my side. Of course, the name still had to go before the Committee on Small-Body Nomenclature. He told me I would find out in a couple of months whether I had successfully named the asteroid.

Around the two-month mark, when new asteroid names are officially released, I went to the Minor Planet Center’s website, hands slightly shaking, and found it: an asteroid named Plimpton. My citation had been published:

(7932) Plimpton = 1989 GP George Plimpton (1927-2003) was an American author, editor, actor, and all-round Renaissance man. As the founding editor of the Paris Review, he fostered the careers of many now-famous writers. A giant in the world of participatory journalism, he chronicled his exploits as an amateur in many fields, especially professional sports. Outer space is big, old, and overwhelmingly difficult to comprehend with our little brains. It becomes almost a human imperative for us to try to confine the universe in one of the few ways we can. Signing our names on objects in space is our minor way of attempting to grasp it, like sending a writer out with the Detroit Lions and hoping he can help us understand what football is really like. I’m well aware that this naming hasn’t changed the universe in any appreciable way. Comets whiz by, stars orbit the galactic center, and craters slowly erode, independent of their titles. The star group officially designated M11 couldn’t care less if it’s known as the Wild Duck Cluster. When Pluto was demoted, while schoolchildren wept, Pluto traced its elliptical path about the sun, unmoved by their tears.

Nonetheless, amid all this indifference, we have to find meaning in any way we can. And I’m happy to think that this little ball of rock is now whirling through space with Plimpton’s name on it, even if it’s blissfully unaware that it, too, is now a clue to 117-Across.

Samuel Arbesman is a postdoctoral fellow in the Department of Health Care Policy at Harvard Medical School. He is a regular contributor to Ideas.

__________

Full article: http://www.boston.com/bostonglobe/ideas/articles/2009/09/27/naming_the_sky/

Read Full Post »

A Damp Moon Overhead

We’re sure that somewhere a marketer is already designing the campaign for Moon Water — available, of course, in attractive, biodegradable containers. Scientists analyzing data collected by three spacecraft have discovered that there may be a fair amount of water — or hydroxyl, which is one hydrogen atom short of being water — on the Moon, albeit spread out in millimeter-thin layers on or near the surface.

This will take some re-imagining, especially after those pictures from the Apollo missions that showed a spectacularly dry, dusty and oasis-free place. It is also a place where temperature swings are extreme, which means it should be inhospitable to a volatile compound like water. These new findings suggest that there is water lurking not only in permanently shadowed craters near the lunar poles but also elsewhere on the lunar surface.

If a decision is made to build a new space base on the Moon — and space enthusiasts differ on the value of doing so — it may be able to extract some water and oxygen from the soil. As for where the water comes from, scientists suggest it may be created when protons in the solar wind collide with the Moon’s surface and trigger reactions that produce water. Forty years ago, there was evidence of water in the lunar soil samples brought back by astronauts. At the time, scientists dismissed the possibility. The Moon was too dry, and they assumed that the samples had been corrupted by Houston’s moist air.

That’s what comes of living on a truly wet planet.

Editorial, New York Times

__________

Full article: http://www.nytimes.com/2009/09/25/opinion/25fri4.html

__________

See also:

In Surprise, Moon Shows Signs of Water

Images of the Moon captured in 1999 by the Cassini spacecraft show regions of trace surface water (blue) and hydroxyl (orange and green).

There appears to be, to the surprise of planetary scientists, water, water everywhere on the Moon, although how many drops future astronauts might be able to drink is not clear.

Data from three spacecraft indicate the widespread presence of water or hydroxyl, a molecule consisting of one hydrogen atom and one oxygen atom as opposed to the two hydrogen and one oxygen atoms that make up a water molecule. The discoveries are being published Thursday on the Web site of the journal Science.

“It’s so startling because it’s so pervasive,” said Lawrence A. Taylor of the University of Tennessee, Knoxville, a co-author of one of the papers that analyzed data from a National Aeronautics and Space Administration instrument aboard India’s Chandrayaan-1 satellite. “It’s like somebody painted the globe.”

For decades, the Moon has been regarded as a completely dry place. The dark side is more than ice cold, but when it passes into sunlight, any ice should have long ago been baked away. The possible exceptions are permanently shadowed craters near the Moon’s poles, and data announced this month by NASA verified the presence of hydrogen in those areas, which would most likely be in the form of water.

If water is somehow more widespread, that could make future settlement of the Moon easier, especially if significant water could be extracted just by heating the soil. Oxygen would also be a key component for breathable air for astronauts, and hydrogen and oxygen can also be used for rocket fuel or power generation.

Samples of lunar soil brought back from NASA’s Apollo missions about four decades ago actually did show signs of water, but most scientists working with the samples, including Dr. Taylor, dismissed the readings as contamination from humid Houston air that seeped in before the rocks were analyzed at NASA’s Johnson Space Center.

“I was one of the ones back in the Apollo days that was firmly against lunar water,” Dr. Taylor said.

Now he is convinced he was wrong. “I’ve eaten my shorts,” he said.

The Chandrayaan-1 data looked at sunlight reflected off the Moon’s surface and found a dip at a wavelength where water and hydroxyl absorb infrared light. Dr. Taylor estimated the concentration at about one quart of water per cubic yard of lunar soil and rock.

Meanwhile, Roger N. Clark of the United States Geological Survey analyzed decade-old data from NASA’s Cassini spacecraft when it passed the Moon en route to Saturn. He, too, found signs of water or hydroxyl, mostly at the poles, but also at lower latitudes.

Scientists working with the Deep Impact spacecraft, which later studied the Comet Tempel 1, also found infrared absorption at the water and hydroxyl wavelengths. More interesting, the amount of absorption — and thus the quantity of water — varied with temperature.

That suggests the water is being created when protons from the solar wind slam into the lunar surface. The collisions may free oxygen atoms in the minerals and allow them to recombine with protons and electrons to form water.

Lori M. Feaga, a research scientist at the University of Maryland who is a member of the team that analyzed the Deep Impact data, said this process would work only to about one millimeter into the lunar surface. If correct, that would not give future astronauts much to drink.

“You would have to scrape the area of a baseball field or a football field to get one quart of water,” she said.

__________

Full article and photo: http://www.nytimes.com/2009/09/24/science/space/24moon.html

Read Full Post »

Lunar Craters May Be Chilliest Spots in Solar System

A photograph from the Lunar Reconnaissance Orbiter showing the rim of Shackleton crater, near the Moon’s south pole.

The shadowy craters near the south pole of the Moon may be the coldest places in the solar system, colder than even Pluto, NASA scientists reported Thursday as they unveiled some of the first findings from the Lunar Reconnaissance Orbiter spacecraft.

“We’re looking at the Moon with new eyes,” said Richard Vondrak, the mission’s project scientist.

The orbiter, launched in June, officially began its one-year mission to map the Moon’s surface this week. But during three months of turning on, testing and calibration of its seven instruments, it had already begun returning data. Notably, its camera captured pictures of the Apollo landing sites, including some of the tracks that the astronauts left on the surface.

In the newly released data, thermal measurements showed that daytime temperatures over much of the surface reached 220 degrees Fahrenheit — hotter than boiling water — before plummeting to frigidness at night.

But the bottoms of the craters, which lie in permanent darkness, never warm above minus 400. Those ultracold temperatures have trapped and held deposits of ice for several billion years. The ice could prove a valuable resource to future explorers, not only as drinking water but also, when the water molecules are broken apart, hydrogen and oxygen.

If it exists, the ice could also hold a detailed historical record of past comet impacts on the Moon, which would provide new hints of the early conditions in the solar system.

A second instrument detected slow-moving neutrons, which indicate the presence of hydrogen in the polar regions. The hydrogen is most likely in the form of water, and that data support the findings of the Lunar Prospector spacecraft a decade ago.

In a twist, the reconnaissance orbiter found hydrogen not only in some craters but also in some areas outside of the craters. Also, some of the craters did not appear to have hydrogen.

That means the water — or some other hydrogen-containing molecule like methane — lies beneath the surface. “It would be very durable there,” Dr. Vondrak said. “What we don’t know is the abundance and how deep it is buried.”

Getting to the material at the bottom of the craters could be difficult. An instrument that maps the topography by bouncing a laser beam off the surface has found the sides of the craters to be steep and rough terrain.

The primary mission of the Lunar Reconnaissance Orbiter, gathering data on the Moon from an altitude of 31 miles to prepare for the return on astronauts, will continue for a year. After that, it will continue to operate to gather information for scientists.

__________

Full article and photo: http://www.nytimes.com/2009/09/18/science/space/18moon.html

Read Full Post »

Ear to the Universe starts listening

US radio array starts its search for extraterrestrial life.

A large array of radio telescopes has begun its first sustained search for extraterrestrial intelligence (SETI) and at rates faster than ever before. Even so, the project has scrambled to find money to stay open and reach its planned size. “We've had a chequered time here,” says Don Backer, director of the Allen Telescope Array (ATA) in Hat Creek, California. “We’re skating on thin ice.”

The ATA has 42 six-metre dishes swivelling in the high desert, far fewer than the 350 dishes planned. In May, the array began combing the centre of our Milky Way Galaxy for alien signals across a broad slice of the radio spectrum. The effort comes 50 years after the concept of SETI was invented.

Previous searches relied on weeks-long observing runs at facilities such as the Arecibo radio telescope in Puerto Rico. The last major search, Project Phoenix — run by the SETI Institute of Mountain View, California — ended in 2004 and required a decade to check 800 stars across a narrow frequency range. The ATA scans the sky much more quickly, allowing a million stars to be checked in just a few decades, says astronomer Seth Shostak of the SETI Institute, which operates the ATA jointly with the University of California at Berkeley. Shostak says sampling a million stars would offer a good chance of striking on one of the 10,000 intelligent civilizations that might be broadcasting in the Milky Way, according to an estimate by Frank Drake, who in 1960 developed a formula to estimate this number.

Private donors, often technologists, began to support SETI in 1993, after the US Congress rescinded NASA funding for it. The family foundation of Microsoft co-founder Paul Allen provided US$25 million, beginning in 2000, to start the ATA. But in 2006, that stream of money was cut off (see Nature 444, 9; 2006), as the SETI Institute and Berkeley struggled to find matching donations to complete the array, which to date has cost $50 million.

Last year, the National Science Foundation (NSF) turned down a proposal to support operations at the array. SETI astronomer Jill Tarter says the NSF’s decision was “like a Catch-22″. The array was big enough at 42 dishes to begin work — and needed money for that — but was not yet big enough to achieve the sensitivity capable of transformational science. Backer hopes that once completed, the ATA, covering vast swaths of sky rapidly, will usher in an era of transient radio astronomy — the study of things, such as supernovae, that go bump in the night rather than shine constantly like stars. Science targets could include the star-fuelling hydrogen that surrounds galaxies, and the radio afterglow of the γ-ray bursts that follow supernovae.

Without the NSF money, the $1.5-million-a-year operation cost is being paid by the US Air Force, which uses the array to track satellites and orbital debris. “It’s keeping our doors open right now,” says Backer. The Allen Foundation has given an additional $5 million since 2006.

Time at the array is split roughly equally: a third to the Air Force, a third to radio astronomy and third to SETI. Increasingly, however, SETI can piggyback on the radio astronomy work.

The ATA is also a testbed for technologies that will be important for the rest of radio astronomy. The array has a wide view of the sky, and within that picture, multiple stars can be analysed simultaneously. This technology, known as beam forming, as well as the immense computing challenge of making a picture from many individual dishes, will be needed in future projects, such as the Square Kilometre Array, which envisions thousands of dishes. “This is where radio astronomy has to go,” says Mark McKinnon, project manager for a $94-million expansion of the 27-dish Very Large Array in New Mexico. The ATA, he says, “are the only people who are actively doing this”.

Backer has a proposal before the NSF to double the number of dishes to 84. The request would match $6 million in NSF money with $5 million committed by five donors, including the Allen Foundation and Taiwan's Institute of Astronomy and Astrophysics. Backer says a decision is due before the end of the year.

__________

Full article: http://www.scientificamerican.com/article.cfm?id=ear-to-the-universe-starts-lis&sc=CAT_PHY_20090918

Read Full Post »

Planck telescope’s first glimpse

Planck maps tiny temperature fluctuations (mottled colours in the strip). These fluctuations correspond to the early distribution of matter in the cosmos. It will take Planck six months to complete a full sky map.

The European telescope sent far from Earth to study the oldest light in the Universe has returned its first images.

The Planck observatory, launched in April, is surveying radiation that first swept out across space just 380,000 years after the Big Bang.

The light holds details about the age, contents and evolution of the cosmos.

The new images show off Planck’s capabilities now that it has been set up, although major science results are not expected for a couple of years.

“The images show first of all that we are working and that we are able to map the sky,” said Planck project scientist Dr Jan Tauber.

“They show that in areas where we expect to see certain things, we do indeed see them, that we are able to image very faint emission, and finally that the two instruments are working in tandem well,” he told BBC News.

Background information

Planck is a European Space Agency (Esa) endeavour.

It was launched on an Ariane rocket and thrown out to an observing position some 1.5 million km from Earth.

PLANCK SPACE TELESCOPE Planck rotates about once per second As it rotates, it gathers precise temperature information from a narrow “strip” of the sky The strips are then fitted together to form a thermal picture of the farthest regions of our Universe It will take about six months to cover the whole sky

It is trying to make the finest-ever measurements of what has become known as the Cosmic Microwave Background (CMB).

This is light that was finally allowed to move out across space once a post-Big-Bang Universe had cooled sufficiently to permit the formation of hydrogen atoms.

Before that time, scientists say, the Universe would have been so hot that matter and radiation would have been “coupled” – the cosmos would have been opaque.

Researchers can detect temperature variations in this ancient heat energy that give them insights into the early structure of the Universe.

With Planck, they also hope to find firm evidence of “inflation”, the faster-than-light expansion that cosmologists believe the Universe experienced in its first, fleeting moments.

Theory predicts this event ought to be “imprinted” in the CMB and the detail should be retrievable with sufficiently sensitive instruments. Planck is designed to have that capability.

Its detectors, or bolometers, are the most sensitive ever flown in space, and operate at a staggering minus 273.05C – just a tenth of a degree above what scientists term “absolute zero”.

“In terms of the instrumental performance, we are getting what we expected from ground testing,” explained Dr Tauber.

Stripped-down

The work to fully commission and optimise Planck for science was completed in mid-August. It was then immediately followed by the “first light” survey that produced the new images.

The pictures are essentially maps of a strip of the sky, one for each the nine frequencies Planck uses. Each map is a ring, about 15 degrees wide, stretching across the full sky.

The telescope is kept phenomenally cold to carry out its work

The telescope has now begun routine operations. It will take the observatory roughly six months to assemble a complete map of the sky. The mission objectives call for at least two of these maps to be made.

It will be at least a couple of years before the Planck research teams are able to present some of their major scientific findings.

“The mission has gone much better than I expected so far,” said Dr Tauber.

“It’s been an unexpectedly smooth ride. We’ve had the usual minor hitches here and there, but I think overall it is doing fantastically well. Everything is chugging away and we are collecting data.”

Planck’s co-passenger on April’s Ariane launch was the Herschel Space Observatory.

It views the cosmos at shorter wavelengths, in the far-infrared, allowing it to peer through clouds of dust and gas to see stars at the moment they are born.

It is currently still in its demonstration phase, collecting images designed to show off its capabilities.

Two of its instruments are working well. A third, however, is currently down after experiencing a fault.

Engineers can switch to a back up system to reactivate the Heterodyne Instrument for the Far Infrared (HiFi) but they do not intend to do that until they can understand the cause the anomaly.

HiFi is a spectrometer that will identify elements and molecules in the clouds of gas and dust which give rise to stars.

__________

Full article and photos: http://news.bbc.co.uk/2/hi/science/nature/8260711.stm

Read Full Post »

Hubble gives glimpse of ‘pillar of creation’

This undated handout image provided by NASA, released Wednesday, Sept. 9, 2009, taken by the refurbished Hubble Space Telescope, shows a celestial object that looks like a delicate butterfly.

The refurbished deep space telescope releases first images since its billion dollar repair

It is a dazzling view of stellar dust and gases billowing in the interstellar void, already described by NASA in biblical language as a “pillar of creation” picture.

The colossal plume rising in the Carina Nebula was among the images unveiled Wednesday for the first time since astronauts upgraded the Hubble Space Telescope for a final time this spring.

Researchers greeted the images giddily, saying that Hubble’s final years will bring a rich harvest of new scientific insight.

“The data here is just spectacular. These are very exciting images,” said Harvey Richer, a University of British Columbia astronomer.

The images of the Carina Nebula show in spectacular fashion the cosmic clouds within which infant stars emerge.

Less obvious but equally stunning was the scale of those images. The cloud pillar in the Carina Nebula is three light-years long – nearly 30 trillion kilometres. Next to it, Dr. Richer said, our solar system would be just a small pinpoint in the picture.

The new images show galaxies sheared and distorted by gravitational pull, light rays bent by dark matter, and an unknown object – either a comet or an asteroid – crashing into Jupiter.

To Dr. Richer, the most exciting new image is a colourful shot of a myriad of red, yellow and blue shimmering stars in Omega Centauri.

Hubble captured in that shot a stellar formation born 12 billion years ago, just within two billion years of the Big Bang that created the universe.

The red stars in the image, Dr. Richer said, are colder giants that have burned up their core hydrogen and swollen to a hundred times their original size, our sun’s fate in five billion years.

For Dr. Richer, that picture gave a taste of his coming research: Hubble will devote 121 orbits next year to looking at a cluster of one million stars in the southern hemisphere, known as 47 Tucanae.

Dr. Richer is hoping Hubble will enable him to find evidence of planets among those ancient stars. The findings could help in uncovering whether life arose early in the universe.

“If planets formed very early in the history of the universe, when these star clusters formed … that would mean there’s been a very long time for life to evolve,” Dr. Richer said.

The images released yesterday were the first since May, when the crew of shuttle mission STS-125 overhauled Hubble for the final time, replacing gyroscopes and batteries, and installing new sensors and cameras. The repair will enable Hubble to keep operating until 2014, when its successor, the James Webb Space Telescope, is to be launched.

“We have a fully functioning, beautifully operating telescope today,” said Hubble senior scientist Dave Leckrone of the Goddard Space Flight Center.

__________

Full article and photos: http://www.theglobeandmail.com/news/world/hubble-gives-glimpse-of-pillar-of-creation/article1280853/

Read Full Post »

Planet-hunter will find alien moons

Planet-hunter will find alien moons

A planet-seeking spacecraft launched in March is so powerful that it will even detect habitable moons around alien worlds, UK scientists said today.

NASA’s $595 million Kepler mission is flying through space checking out 100,000 stars looking for other planets resembling Earth.

Its instruments scan the light of stars in one small region of the Milky Way, watching for little blips revealing that a planet is passing in front of one of them.

Now a team led by Dr David Kipping of University College London says they may even find habitable moons too. They will be able to support alien life if they live in the “Goldilocks zone” around a star where conditions are not too hot or cold but just right.

Dr Kipping, who believed that many thousands or even millions of these moons exist in the galaxy, has devised a way to discover them by looking for a wobble in the planet that each is orbiting, due to its gravitational pull. The new research shows that Kepler’s telescope will be powerful enough to spot the changes in the planet’s position and velocity.

An alien solar system’s moon – dubbed an exomoon – will be easiest to detect if it is orbiting a fluffy planet like Saturn, say the scientists, rather than a more dense or solid world. This is because Saturn’s lightness would make it wobble much more than a heavy planet.

If the Saturn-like planet is at the right distance from its star, then the temperature will allow liquid water to be stable on any sufficiently large moons in orbit around it and these could then be habitable.

The team found that moons as small as a fifth the weight of the Earth should be easily detectable with the Kepler spaceprobe around 25,000 stars up to 500 light-years away from Earth.

Star Wars fans are already wondering if Kepler might find planetary satellites like the fabled Forested Moon of Endor, the planet that was home to the Ewoks.

Dr Kipping said: “For the first time, we have demonstrated that potentially habitable moons up to hundreds of light years away may be detected with current instrumentation.

“As we ran the simulations, even we were surprised that moons as small as one-fifth of the Earth’s mass could be spotted. It seems probable that many thousands, possibly millions, of habitable exomoons exist in the Galaxy and now we can start to look for them.”

The team’s findings will be published by the Royal Astronomical Society. Last month, Skymania News told how Kepler had detected the phases of an extrasolar planet.
___________

Full article and photo: http://www.scientificamerican.com/article.cfm?id=planet-hunter-will-find-alien-moons-2009-09&sc=CAT_SPC_20090909

Read Full Post »

A One-Way Ticket to Mars

NOW that the hype surrounding the 40th anniversary of the Moon landings has come and gone, we are faced with the grim reality that if we want to send humans back to the Moon the investment is likely to run in excess of $150 billion. The cost to get to Mars could easily be two to four times that, if it is possible at all.

This is the issue being wrestled with by a NASA panel, convened this year and led by Norman Augustine, a former chief executive of Lockheed Martin, that will in the coming weeks present President Obama with options for the near-term future of human spaceflight. It is quickly becoming clear that going to the Moon or Mars in the next decade or two will be impossible without a much bigger budget than has so far been allocated. Is it worth it?

The most challenging impediment to human travel to Mars does not seem to involve the complicated launching, propulsion, guidance or landing technologies but something far more mundane: the radiation emanating from the Sun’s cosmic rays. The shielding necessary to ensure the astronauts do not get a lethal dose of solar radiation on a round trip to Mars may very well make the spacecraft so heavy that the amount of fuel needed becomes prohibitive.

There is, however, a way to surmount this problem while reducing the cost and technical requirements, but it demands that we ask this vexing question: Why are we so interested in bringing the Mars astronauts home again?

While the idea of sending astronauts aloft never to return is jarring upon first hearing, the rationale for one-way trips into space has both historical and practical roots. Colonists and pilgrims seldom set off for the New World with the expectation of a return trip, usually because the places they were leaving were pretty intolerable anyway. Give us a century or two and we may turn the whole planet into a place from which many people might be happy to depart.

Moreover, one of the reasons that is sometimes given for sending humans into space is that we need to move beyond Earth if we are to improve our species’ chances of survival should something terrible happen back home. This requires people to leave, and stay away.

There are more immediate and pragmatic reasons to consider one-way human space exploration missions.

First, money. Much of the cost of a voyage to Mars will be spent on coming home again. If the fuel for the return is carried on the ship, this greatly increases the mass of the ship, which in turn requires even more fuel.

The president of the Mars Society, Robert Zubrin, has offered one possible solution: two ships, sent separately. The first would be sent unmanned and, once there, combine onboard hydrogen with carbon dioxide from the Martian atmosphere to generate the fuel for the return trip; the second would take the astronauts there, and then be left behind. But once arrival is decoupled from return, one should ask whether the return trip is really necessary.

Surely if the point of sending astronauts is to be able to carry out scientific experiments that robots cannot do (something I am highly skeptical of and one of the reasons I don’t believe we should use science to attempt to justify human space exploration), then the longer they spend on the planet the more experiments they can do.

Moreover, if the radiation problems cannot be adequately resolved then the longevity of astronauts signing up for a Mars round trip would be severely compromised in any case. As cruel as it may sound, the astronauts would probably best use their remaining time living and working on Mars rather than dying at home.

If it sounds unrealistic to suggest that astronauts would be willing to leave home never to return alive, then consider the results of several informal surveys I and several colleagues have conducted recently. One of my peers in Arizona recently accompanied a group of scientists and engineers from the Jet Propulsion Laboratory on a geological field trip. During the day, he asked how many would be willing to go on a one-way mission into space. Every member of the group raised his hand. The lure of space travel remains intoxicating for a generation brought up on “Star Trek” and “Star Wars.”

We might want to restrict the voyage to older astronauts, whose longevity is limited in any case. Here again, I have found a significant fraction of scientists older than 65 who would be willing to live out their remaining years on the red planet or elsewhere. With older scientists, there would be additional health complications, to be sure, but the necessary medical personnel and equipment would still probably be cheaper than designing a return mission.

Delivering food and supplies to these new pioneers — along with the tools to grow and build whatever they need, for however long they live on the red planet — is likewise more reasonable and may be less expensive than designing a ticket home. Certainly, as in the Zubrin proposal, unmanned spacecraft could provide the crucial supply lines.

The largest stumbling block to a consideration of one-way missions is probably political. NASA and Congress are unlikely to do something that could be perceived as signing the death warrants of astronauts.

Nevertheless, human space travel is so expensive and so dangerous that we are going to need novel, even extreme solutions if we really want to expand the range of human civilization beyond our own planet. To boldly go where no one has gone before does not require coming home again.

Lawrence M. Krauss, the director of the Origins Initiative at Arizona State University, is the author of “The Physics of ‘Star Trek.’”

__________

Full article and photo: http://www.nytimes.com/2009/09/01/opinion/01krauss.html

__________

See also:

How to Get Humans on Mars: Make It a One-Way Trip

Landing humans on Mars is a completely achievable feat with current technology—if you are okay with the idea of a one-way ticket, points out physicist and Scientific American columnist Lawrence Krauss in an op-ed in yesterday’s New York Times .

The problem today isn’t the launch capabilities or the guidance systems or the navigation. It is the energetic particles from the sun, which can rip apart DNA. Space travelers returning home from a Mars mission would soon die from this radiation poisoning, if they managed to survive the experience at all. A protective shield would simply be too massive to be practical; assuming no technological breakthroughs, the shield would weigh around 400 tons—much too massive for today’s heavy-lift vehicles.

Krauss notes that a one-way trip would be more sensible. (But like most scientists, Krauss thinks that robots can accomplish as much as humans can in terms of doing actual science in space.) We could send senior-citizen volunteers to the Red Planet, where they could spend their final months conducting experiments, laying the groundwork for future permanent settlements, and digging their own graves.

The idea of a one-way trip has been kicked around for years. I first became aware of it some 10 years ago, when SciAm editor George Musser (currently installing solar panels on his home) brought it up at one of our story meetings. As our resident Mars-ophile, George said he would go once and for all, without hesitation—and he was the only one on staff at the time who would. An informal poll of 12 others on staff this morning revealed two other yays, albeit with the general qualification of not having much to live for on Earth.

As news editor, I would certainly appreciate having a Mars bureau, even if for just a couple of months. Imagine the tweets during a voyage of possibly 200-plus days in an enclosed environment with the same small group. Day 65: Main toilet is broken—again! Day 110: I should have smuggled more beer on board. Day 175: I can’t believe I’m going to be buried with these people.

A round-trip Mars mission might be achievable, though—not with faster rockets, but with biomedical advances. Drugs that safely combat the effects of radiation poisoning seem to be the only way to make a voyage back home feasible, as Eugene N. Parker points out in an article in the March 2006 issue and in a Science Talk podcast interview.

___________

Full article and photo: http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=how-to-get-humans-on-mars-make-it-a-2009-09-02&sc=DD_20090903

Read Full Post »