New Planet: Another “Earth” Discovered By Scientists

COURTESY: NATIONAL SCIENCE FOUNDATION
R. Paul Butler, Planet co-discoverer
Steve Vogt, Planet co-discoverer

Astronomers have announced they have discovered an earth like planet that could support the crucial conditions needed for life to exist. The new planet sits directly in the middle of what is referred to as the habitable or Goldilocks zone (Gliese 581 g), unlike any of the nearly 500 other planets astronomers have found outside Earth’s solar system. It also is in Earth’s galactic neighbourhood, suggesting that plenty of Earth-like planets circle other stars. Astronomers say the planet is neither too far from its star, not too close and could contain liquid water.

The Darkest World: Scientists Discover ‘Darth Vader’ Planet

The distant exoplanet TrES-2b, shown here in an artist's conception, is darker than the blackest coal. It refuses to give back light. Why? That's a mystery

The polarities of darkness and light have been central to human cultural imaginings since our origins.

In the 5th century B.C. there was Zoroastrian religion, based on the eternal battle between darkness (evil) and light (spiritual purity). In the modern world we have the mythic conflict between Luke Skywalker in his white tunic and his black-shrouded, fallen father, Darth Vader. Given our penchant for pulling the world apart into this kind of dichotomy, it is, perhaps, no wonder that the recent discovery of the darkest of dark planets has made news.

A few weeks ago, two astronomers announced the discovery of TrES-2b via the Kepler spacecraft. The planet is a so-called “Hot Jupiter” — a large gas giant orbiting extremely close to its sun-like star (the whole system is about 750 light years away from us).

What makes TrES-2b so remarkable is its refusal to give back light. The scientific word for reflectivity is albedo. The Earth reflects about 37 percent or 0.37 of the light it receives from the sun. That is why we present such a beautiful bright blue face to the universe.

TrES-2b is another story entirely. It bounces back less than 1 percent (0.01) of the light it receives from its star. That means the planet is blacker than coal. Seen from space, TrES-2b would barely be visible.

It is not clear yet why TrES-2b is so dark. It may be that the intense heat from the nearby star has formed strange, light-absorbing compounds in the planet’s atmosphere.

“It’s a mystery as to what’s causing it to be so dark,” co-discover David Kipping told Space.com. “There’s a good chance it’s a chemical we haven’t even thought of yet.”

A world darker than coal, darker than night and darker than the heart of wickedness. You can provide your own metaphor, analogy or back story if you want.

One of the great beauties of science is the way it lets us discover how much richer the world is than our imagination might have conceived. Then our imaginations find their own uses for these discoveries, making the world we find our own.

You can keep up with more of what Adam Frank is thinking on Facebook.

News in Brief: Atom & Cosmos

By Science News Staff
Web edition : 2:58 pm

Sun snot
Someone should teach the Sun some manners. When it sneezed on June 7, the sun blew an enormous glob of dark plasma into space — and NASA’s Solar Dynamics Observatory caught it on tape. The 20,000-degree Celsius eruption — actually rather chilly by solar standards — can be seen raining back onto the sun’s surface in blobs and streamers. Some of the material made a beeline for sunspots hundreds of thousands of kilometers from the eruption site. Scientists say an unstable magnetic filament triggered the eruption, which sent shock waves halfway around the star and blew around 4 trillion kilograms of charged particles away from the sun — one of the largest events of its type measured so far. Gesundheit. —Nadia Drake

Death of a comet
For the first time, astronomers have spotted the final death throes of a comet heading into the sun. Scientists have watched plenty of comets come close to the sun and then vanish, but witnessing the actual destruction is tough, John Brown of the University of Glasgow in Scotland and colleagues report online July 10 at arXiv.org. Their new calculations suggest that lightweight comets explode high above the sun; only comets with nuclei heavier than about 100 billion metric tons manage to reach the surface to die. The Solar Dynamics Observatory photographed such a cometary plunge in early July. —Alexandra Witze

Hottest known planet
Welcome to Hades, a.k.a. WASP-33b. Astronomers have identified this planet, which orbits a star in the constellation Andromeda, as the hottest known. Its surface is a scalding 3,350 degrees Celsius, thanks to the inherent heat of its parent star and the fact that the planet is so close to it, orbiting just once every 1.22 days. A team led by Alexis Smith of Keele University in England reported the finding online July 8 in the Monthly Notices of the Royal Astronomical Society. —Alexandra Witze

Galactic menopause
Both the Milky Way and its neighbor, the Andromeda galaxy, could be in the midst of a midlife crisis. Astronomers have used computer models and galaxy surveys to assess how far the two galaxies have come in their life cycle, as measured by the color of their stars. Both appear to be roughly halfway between young blue stars and red older stars, a team from Swinburne University of Technology in Hawthorn, Australia report in the August 1 Astrophysical Journal. Scientists may thus be able to examine an important galactic life change as it happens. —Alexandra Witze

Antimatter Tevatron mystery gains ground

US particle physicists are inching closer to determining why the Universe exists in its current form, made overwhelmingly of matter.

Physics suggests equal amounts of matter and antimatter should have been made in the Big Bang.

In 2010, researchers at the Tevatron accelerator claimed preliminary results showing a small excess of matter over antimatter as particles decayed.

The team has submitted a paper showing those results are on a firmer footing.

Each of the fundamental particles known has an antimatter cousin, with identical properties but opposite electric charge.

When a particle encounters its antiparticle, they “annihilate” each other, disappearing in a high-energy flash of light.

The question remains: why did this not occur in the early Universe with the equal amounts of matter and antimatter, resulting in a Universe devoid of both?

New physics?
The Tevatron results come from a shower of particles produced at the facility when smashing protons into their antimatter counterparts, antiprotons.

The proton-antiproton collisions in turn create a number of different particles, and the team operating the Tevatron’s DZero detector first noticed a discrepancy in the decay of particles called B mesons.

These decayed into pairs of particles called muons alongside pairs of their antimatter versions, antimuons. But, as the team reported in May 2010 in a paper published in Physical Review Letters, there was a notable 1% excess of the matter particles.

However, unpicking important events in the soup of interactions created in particle physics experiments meant that those measurements were associated with a level of uncertainty – reflecting the probability that the effect they see is a random statistical occurrence, rather than new physics.

The researchers now have 50% more data to work with, and have tried to establish that their earlier result in fact came from the particle decays that they first proposed.

As they reported this Thursday, they have now reduced the uncertainty in their experiment to a level of “3.9 sigma”, or 3.9 standard deviations – equivalent to a 0.005% probability that the effect is a fluke.

But particle physics has a strict definition for what may be called a discovery – the “five sigma” level of certainty, or about a 0.00003% chance that the effect is not real – which the team must show before they can claim to have solved the long-standing matter/antimatter mystery.

Statistics of a ‘discovery’
Particle physics has an accepted definition for a “discovery”: a five-sigma level of certainty. The number of sigmas (or standard deviations) is a measure of how unlikely it is that an experimental result is simply down to chance rather than a real effect. Similarly, tossing a coin and getting a number of heads in a row may just be chance, rather than a sign of a “loaded” coin. The “three sigma” level represents about the same likelihood of tossing more than eight heads in a row. Five sigma, on the other hand, would correspond to tossing more than 20 in a row. A five-sigma result is highly unlikely to happen by chance, and thus an experimental result becomes an accepted discovery.

Google-backed Moon robot teams confirmed

18 February 2011 Last updated at 08:51 ET

The Lunar X-Prizes support Nasa's efforts to reduce the costs of space exploration

The final line-up of teams competing for the $30 million (£18.5m) robotic Moon-explorer prize has been confirmed.
The prize will go to the builders of the first robot to send back video as it travels over 500 metres of the Moon’s surface.

Competition organisers hope to spur the development of low-cost robotic space exploration.

The Google-sponsored Lunar X-Prize will be fought over by 29 teams from 17 different countries.

Organisers believe that the competition – first announced in 2007 – could have a winner by 2015.

“The official private race to the Moon is on,” said Peter Diamandis, chief executive of the X-Prize Foundation.

The teams come from a wildly divergent background, ranging from non-profit consortia and university groups to well-funded businesses.

Robotic explorers
Several of the teams have already bought rides on spacecraft to transport their robots.

Astrobotic Technology, a spin off-off from Carnegie Mellon University has signed a deal with SpaceX – the private space company set up by PayPal founder Elon Musk – to use its Falcon 9 rocket.

Meanwhile, government-backed space agencies are also planning to send craft to the Moon.

Spacecraft from a joint Russian and Indian team and a separate one from China are pencilled to set off for the Moon in 2013.

But the X-Prize’s backers think the future of space exploration will be driven by privately-funded groups.

“The most successful and revolutionary discoveries often come from small, entrepreneurial teams,” said Tiffany Montague, of Google Space Initiatives.

NASA Unveils Arsenic Life Form

By Rachel Ehrenberg, Science News

When cooking up the stuff of life, you can’t just substitute margarine for butter. Or so scientists thought.

But now researchers have coaxed a microbe to build itself with arsenic in the place of phosphorus, an unprecedented substitution of one of the six essential ingredients of life. The bacterium appears to have incorporated a form of arsenic into its cellular machinery, and even its DNA, scientists report online Dec. 2 in Science.

Arsenic is toxic and is thought to be too chemically unstable to do the work of phosphorus, which includes tasks such as holding DNA in a tidy double helix, activating proteins and getting passed around to provide energy in cells. If the new results are validated, they have huge implications for basic biochemistry and the origin and evolution of life, both on Earth and elsewhere in the universe.

“This is an amazing result, a striking, very important and astonishing result — if true,” says molecular chemist Alan Schwartz of Radboud University Nijmegen in the Netherlands. “I’m even more skeptical than usual, because of the implications. But it is fascinating work. It is original, and it is possibly very important.”

The experiments began with sediment from eastern California’s Mono Lake, which teems with shrimp, flies and algae that can survive the lake’s strange chemistry. Mono Lake formed in a closed basin — any water that leaves does so by evaporation — making the lake almost three times as salty as the ocean. It is highly alkaline and rich in carbonates, phosphorus, arsenic and sulfur.

Led by Felisa Wolfe-Simon of NASA’s Astrobiology Institute and the U.S. Geological Survey in Menlo Park, California, the researchers cultured microbes from the Lake Mono sediment. The microbes got a typical diet of sugar, vitamins and some trace metals, but no phosphate, biology’s favorite form of phosphorus. Then the team started force-feeding the critters arsenate, an analogous form of arsenic, in greater and greater quantities.

One microbe in particular — now identified as strain GFAJ-1 of the salt-loving, mostly marine family Halomonadaceae — was plucked out and cultured in test tubes. Some were fed loads of arsenate; others got phosphate. While the microbes subsisting on arsenate didn’t grow as much as those getting phosphate, they still grew steadily, doubling their ranks every two days, says Wolfe-Simon. And while the research team couldn’t eliminate every trace of the phosphate from the original culture, detection and analytical techniques suggests that GFAJ-1 started using arsenate as a building block in phosphate’s place.

“These data show that we are getting substitution across the board,” Wolfe-Simon says. “This microbe, if we are correct, has solved the challenge of being alive in a different way.”

Arsenic sits right below phosphorus in the periodic table and so, chemically speaking, isn’t that different, Wolfe-Simon notes. And of the six essential elements of life — carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur (aka CHNOPS) — phosphorus has a relatively spotty distribution on the Earth’s surface. If a microbe in a test tube can be coerced to live on arsenic, perhaps life’s primordial home was also arsenic-rich and life that used phosphorus came later. A “shadow biosphere” of arsenic-based life may even exist unseen on Earth, or on some lonely rock in space.

“It isn’t about arsenic, and it isn’t about Mono Lake,” says Wolfe-Simon. “There’s something fundamental about understanding the flexibility of life. Any life, a microbe, a tree, you grind it up and it’s going to be CHNOPS. But we have a single sample of life. You can’t look for what you don’t know.”

Similarities between arsenic and phosphorus are also what make the element so poisonous. Life often can’t distinguish between the two, and arsenic can insinuate itself into cells. There, it competes with phosphorus, grabs onto sulfur groups, or otherwise gums up the works, causing cell death. Some microbes “breathe” by passing electrons to arsenic, but even in those cases the toxic element stays outside the cell.

Researchers are having a hard time wrapping their minds around arsenate doing the job of phosphate in cells. The ‘P’ in ATP, the energy currency for all of life, stands for phosphate. And the backbone of the DNA double helix, the molecule containing the genetic instructions for life, is made of phosphate. Basic biochemistry says that these molecules would be so unstable that they would fall apart if they were built with arsenate instead of phosphate.

“Every organism that we know of uses ATP and phosphorylated DNA,” says biogeochemist Matthew Pasek of the University of South Florida in Tampa. He says the new research is both fascinating and fantastic. So fantastic, that a lot of work is needed to conclusively show exactly how the microbe is using arsenate.

Both phosphate and arsenate can clump up into groups, and with their slightly negative electric charge, slightly positive DNA would be attracted to such clumps, says Pasek. Perhaps the arsenic detected in the DNA fraction was actually a nearby clump that the DNA wrapped itself around, he speculates.

The microbe may be substituting for phosphate with discretion, says geochemist Everett Shock of Arizona State University in Tempe, using arsenic in some places but not others. But Shock says the real value of the work isn’t in the specifics. “This introduces the possibility that there can be a substitution for one of the major elements of life,” he says. Such research “stretches the perspective. Now we’ll have to see how far this can go.”

For an audio report go here or download the mp3.

NASA Deep Impact spacecraft flies by small comet

By ALICIA CHANG
Thu Nov 4, 9:00 pm ET

PASADENA, Calif. – A NASA spacecraft sped past a small comet Thursday, beaming pictures back to Earth that gave scientists a rare close-up view of its center. Mission controllers burst into applause upon seeing images from the flyby that revealed a peanut-shaped comet belching jets of poisonous gases.

“It’s hyperactive, small and feisty,” said mission scientist Don Yeomans of the NASA Jet Propulsion Laboratory.

The close encounter occurred 13 million miles from Earth when the Deep Impact craft, hurtling through space, flew within 435 miles of comet Hartley 2. It’s only the fifth time that a comet’s core has been viewed up close.

Scientists are interested in comets because they’re icy leftovers from the formation of the solar system about 4.5 billion years ago. Studying them could provide clues to how Earth and the planets formed and evolved.

“The scientific work is just beginning now,” principal investigator Michael A’Hearn, of the University of Maryland, said at a post-mission news conference. “The engineers did a fantastic job of getting us data. Now we have to make sense of it.”

Thursday’s flyby is actually an encore mission for Deep Impact. It set off cosmic fireworks on July 4, 2005, when it fired a copper probe that crashed into comet Tempel 1. The high-speed collision spewed a cloud of debris into space, giving scientists their first peek of the interior.

After the $333 million comet-buster, NASA recycled Deep Impact for a new mission to visit another comet. It was supposed to target comet Boethin in 2008, but it was nowhere to be found. Scientists theorized the comet may have broken up into small pieces.

Deep Impact was then redirected to Hartley 2. Roughly 1 1/2 miles long, Hartley 2 is the smallest comet to be photographed up close. On its way there, the craft spent several months scanning a cluster of nearby stars with known planets circling them.

While its latest task lacks the Hollywood drama of the Tempel 1 crash, researchers still consider it an important mission. Unlike in 2005, viewers could not see Thursday’s comet encounter in real time since the craft’s antenna was not pointed at Earth as it flew past Hartley 2.

“There are a lot of open questions about comets and their life cycle,” said project manager Tim Larson of JPL, which manages the $42 million encore mission. “We have so little data that every time we have an opportunity to go near a comet, it’s a chance to expand our knowledge.”

Since September, Deep Impact has been stalking Hartley 2 like a paparazzo, taking images every 5 minutes and gathering data. It’s the first craft to visit two comets.

Deep Impact will observe Hartley 2 until Thanksgiving and then wait for further instructions from NASA. The space agency has not decided whether to reuse Deep Impact again. The craft does not have enough fuel on board to do another flyby.

The latest images add to scientists’ cometary photo album, said astronomer David Jewitt of the University of California, Los Angeles, who had no role in the project.

“We’re visual animals and nothing seems wholly real to us until we have a nice picture of it,” Jewitt said.

Hartley 2 passed within 11 million miles of Earth on Oct. 20 — the closest it has been to our planet since its discovery in 1986.

British-born astronomer Malcolm Hartley, who discovered the comet, said he never imagined a spacecraft would get so close to his namesake find.

“When I saw the comet, it was millions and millions of kilometers away,” he said. “I’m extremely excited and feel very privileged. After all, I only discovered it.”

Moon Crater Has More Water Than Parts of Earth

Pretty cool… Thought you might find this interesting…  

Mr. K   

Moon Crater Has More Water Than Parts of Earth
By Mike Wall
SPACE.com Senior Writer
posted: 21 October 2010
02:02 pm ET

A frigid crater at the moon’s south pole is jam-packed with water ice, with some spots wetter than Earth’s Sahara desert, boosting hopes for future lunar bases.

That’s the picture painted by six new studies that analyzed the intentional moon crash of a NASA spacecraft on Oct. 9, 2009. The agency’s LCROSS probe was looking for signs of water when it smashed into Cabeus crater at the moon’s south pole last year, and the spacecraft found plenty of it, as scientists announced last year.  

The new results expand on those original findings, revealing that Cabeus harbors many other compounds, too — stuff like carbon monoxide, ammonia, methane, mercury and silver.  

And the new studies — reported as six separate papers in the Oct. 22 issue of the journal Science — put a solid number on the amount of frozen water at the moon’s south pole. [10 Coolest New Moon Discoveries]  

Water ice makes up about 5.6 percent of the total mass on the floor of Cabeus — making the crater about twice as wet as Sahara Desert soil, according to LCROSS mission principal investigator Tony Colaprete.  

“That is a surprise,” said Colaprete, who works at NASA’s Ames Research Center in Moffett Field, Calif. “And it has a lot of ramifications in terms of our understanding of water and other volatiles on the moon.”  

Moon water surprises  

The high concentration of water ice came as a bit of a shock to mission scientists.  

“I still can’t really wrap my brain around it,” said Colaprete, who led one of the studies reported in the journal Science and is a co-author on several others. “There are places on the moon that are wetter than parts of Earth — that’s kind of neat.”  

This moon water ice is also relatively pure, the researchers found.  

The LCROSS spacecraft picked up ice signatures for four full minutes. If the ice crystals had been impregnated with lots of lunar dirt grains, that signal would have faded within 20 seconds or so, according to Colaprete, since grains heat up fast in sunlight.  

“For ice crystals to last more than a minute, they need to be 80 or 90 percent water ice,” Colaprete told SPACE.com. “Otherwise they will sublime, evaporate in the sunlight.”  

Another intriguing result was the variety and amount of other substances inside Cabeus.  

LCROSS and a sister probe, the Lunar Reconnaissance Orbiter (LRO), found evidence of all kinds of compounds, including elemental hydrogen, carbon monoxide, ammonia, methane, mercury, calcium, magnesium and silver. And these materials made up a surprisingly large chunk of the crater floor.  

“Where we impacted, up to 20 percent was something other than dirt,” Colaprete said. “It was ices, volatiles, light metals. That was a surprise, that you had so much of this material in there.”  

Smashing a probe into the moon  

The LCROSS spacecraft, short for Lunar Crater Observation and Sensing Satellite, was built to live fast and die young. It launched, along with LRO, in June 2009 aboard a Centaur rocket.  

On Oct. 9 of that year, the Centaur hurtled solo toward Cabeus, a 60-mile-wide (97-km-wide) crater near the moon’s south pole. When the rocket hit, it raised a huge debris plume up into the sunlight, where the two probes could scan it with their instruments, which included cameras and various spectrometers.  

LCROSS plummeted just four minutes behind the Centaur, getting an up-close look at the ejecta cloud before smashing into the lunar surface itself. The LRO spacecraft watched all this action from above, peering at the two impacts’ debris plumes. It remains in lunar orbit today, mapping the moon’s surface.  

Last November, scientists announced that those plumes contained “significant amounts” of water.  

Now, after analyzing more of the data gathered by both LCROSS and LRO, they have a much better idea of just what’s in Cabeus crater — and they’re gaining a better understanding of how it may have gotten there.  

Where did all of this stuff come from?  

The researchers are still trying to work out exactly how all of these compounds — the water and everything else — made their way to the bottom of Cabeus crater.  

The original source of much of the material is likely asteroid or comet impacts, scientists said. Once they arrived, the compounds could have moved all over the lunar surface — liberated from the dirt by micrometeorite strikes or solar heating — until they hit a cold trap like Cabeus.  

The permanently shadowed inside of Cabeus is among the coldest places in the solar system, with average temperatures around minus 387 degrees Fahrenheit (minus 233 Celsius). Many compounds would sink into these frigid depths and never surface again. So water, ammonia and everything else could keep accumulating in the crater for billions of years.  

“This place looks like it’s a treasure chest of elements, of compounds that have been released all over the moon,” said Peter Schultz of Brown University, lead author of one of the Science papers and co-author of another one. “And they’ve been put in this bucket in the permanent shadows.”  

But Colaprete thinks there’s more to the story at Cabeus.  

The new research details, in part, how the crater was chosen for the LCROSS kamikaze mission: LRO instruments picked up a strong hydrogen signal in the crater, indicating the likely presence of lots of water ice.  

But there are many freezing-cold craters at the moon’s south pole, and most of them didn’t show such a strong hydrogen signature. And some of the places with lots of hydrogen aren’t even in permanent shadow.  

Cabeus stands out, indicating that there’s likely more to accumulating large quantities of water — and other materials — than just frigid temperatures.  

“I think the best model right now, given the compounds we see, is that the Cabeus site is actually a comet impact site,” Colaprete said.  

That’s not to suggest that volatiles don’t migrate around the moon and get trapped in the bottom of permanently shadowed craters. That’s likely happening, too, Colaprete said. But that background process likely can’t fully explain Cabeus.  

“It seems to suggest that our old thinking about this kind of uniform emplacement of water over a billion years is only a part — and maybe a minor part — of the story when it comes to these pockets of high concentrations,” Colaprete said.  

Going to the moon?  

The high concentration of water ice at the bottom of Cabeus is good news for anyone pushing for bases at the moon’s poles.  

Future moon-dwellers could conceivably mine such large quantities of ice efficiently. They could it process it into its constituent hydrogen and oxygen, prime ingredients of rocket fuel. And they could melt the ice down and drink it — provided they remove some of the nasty stuff, like mercury.  

Some of the other compounds found in the crater — such as elemental hydrogen, methane and ammonia— could be useful, too, according to Colaprete.  

“These places are definitely resource-rich and suggest that they would be advantageous to use for producing resources, if it ever came to that,” Colaprete said.  

There’s no reason to think Cabeus is an anomaly, Colaprete said. There could be other super-enriched sites like it at both the north and south poles.  

And the poles more generally could harbor a lot of water ice, according to the new research. Modeling results support the possibility that there may be large regions of lunar “permafrost,” where relatively accessible ice could be trapped below the surface, even in warmer spots that see the sun occasionally.  

And that’s a good thing, because Cabeus itself may not be the ideal site for a lunar base.  

For one thing, the floor of the crater is in permanent shadow and incredibly cold. It’s tough to design equipment that can operate at temperatures of minus 387 degrees Fahrenheit (minus 233 Celsius)–and that equipment likely can’t be solar-powered.  

Also, the findings suggest that all those volatile compounds form a soft, frosty layer on the Cabeus floor that could bog down rovers or landers. When the Centaur hit, LCROSS measured a 0.3 second delay until a big heat flash resulted.  

That’s a very long lag, especially considering that the rocket was moving at 5,580 mph (9,000 kph). The result suggests that the soil is very porous, perhaps almost fluffy.  

“If we had hit rock, that flash would have happened almost instantaneously,” Colaprete said.  

Sacrificing itself for science   

The $79 million LCROSS mission wasn’t the first to find water on the moon — three other spacecraft had previously detected evidence of water ice on the lunar surface, a finding announced just a few weeks before LCROSS’ kamikaze plunge.  

But the LCROSS mission is yielding new insights that should change how researchers think about the moon, according to Colaprete. That means the spacecraft’s sacrifice was worth it.  

“We went out with a bang,” Colaprete said, “and the return has just been phenomenal.”