Monday, December 20, 2010

Stay Connected with NASA for the Solstice Lunar Eclipse!


The first total lunar eclipse in two years will grace the sky the night of Monday, Dec. 20, and we want you to be there. Sure, it's a school night, but with winter solstice and a new year upon us, what better time to gather your family and friends to see the moon in a new light?

At NASA, we're pretty excited for this year's lunar eclipse, so we're offering a number of features and activities for astronomy buffs and moon-gazers alike. To learn about the science behind eclipses, visit NASA's Eclipse page, where Mr. Eclipse provides information about viewing the eclipse from all over the United States.

Want to know more about the lunar eclipse? Lunar experts from NASA's Marshall Space Flight Center will be hosting two live Web chats to discuss the eclipse. On Monday, Dec. 20 from 3-4 p.m. EST, Dr. Rob Suggs will answer your questions. Later on Dec. 20, make plans to stay "Up All Night" with astronomer Mitzi Adams at she answers your questions from midnight to 5:00 a.m. EST.

Starting now, you can subscribe to NASA JPL's "I'm There: Lunar Eclipse" text campaign to connect with others in your area by texting us your viewing location and comments on the night of the eclipse. To sign up, text IMTHERE to 67463 and we'll send you a reminder to go out and watch on Dec. 20 (message and data rates may apply).

Want to share or flip through photos of the eclipsed moon? Join NASA JPL's lunar eclipse Flickr group and connect with other professional and amateur photographers as they capture the moon's path through the Earth's shadow. We'll choose one lucky photographer to have his or her work featured as official JPL wallpaper at http://www.jpl.nasa.gov/wallpaper.

If you don't want to brave the December chill, or if your weather doesn't cooperate for lunar viewing, we have you covered! A live video feed of the lunar eclipse will be streamed online on Dec. 20. The camera is mounted at NASA's Marshall Space Flight Center in Huntsville, Ala.

On Dec. 20 and 21, join the conversation on Twitter by including #eclipse and @NASAJPL in your lunar eclipse tweets, and you may even see them show up among our live comment stream on NASA JPL's "I'm There: Lunar Eclipse" program.

Thursday, December 16, 2010

A New Trio of Expedition 26 Blasts Off Toward Station


A new trio of Expedition 26 flight engineers blasted off Wednesday from the Baikonur Cosmodrome in Kazakhstan at 2:09 p.m. EST (1:09 a.m. Thursday, Baikonur time). Dmitry Kondratyev, Catherine Coleman and Paolo Nespoli are onboard the Soyuz TMA-20 spacecraft and headed for a docking with the International Space Station.

West Antarctica is Seeing Dramatic Ice Loss


Scientists have previously shown that West Antarctica is losing ice, but how that ice is lost remained unclear. Now, using data from Earth observing satellites and airborne science missions, scientists are closing in on ice loss culprits above and below the ice.

The findings, presented Dec. 15 at the fall meeting of the American Geophysical Union (AGU) in San Francisco, Calif., are expected to improve predictions of sea level rise.

Time Not Healing Glacial Wounds

A new analysis by Ted Scambos, a glaciologist at the National Snow and Ice Data Center in Boulder Colo., and colleagues found that more than a decade after two major Antarctic ice shelves collapsed, glaciers once buttressed by the shelves continue to lose ice.

Changes are most evident in the West Antarctic Ice Sheet and along the Antarctic Peninsula. A spine of mountains forces passing winds to give up their moisture as snow, feeding glaciers that in turn feed the ice shelves that jut out into the Southern Ocean. More than a decade ago, dramatic changes started affecting a series of ice shelves, collectively called Larsen, along the Peninsula's northeast coast. In 1995, Larsen A was the first to collapse followed by a larger loss of Larsen B in 2002. Today, a small piece of the Larsen B and the entirety of the vast Larsen C hang on.

Investigating how the glaciers have responded to the loss of these ice shelf "dams," Scambos and colleagues tracked elevation information using data from satellites such as NASA's Ice, Cloud and land Elevation Satellite (ICESat) and previous airborne missions. They show that between 2001 and 2006, glaciers feeding Larsen A and Larsen B lost 12 gigatons of ice loss per year, or 30 percent of all ice lost throughout the Peninsula.

Moreover, the continued draw down of glaciers, such as Drygalski Glacier, fifteen years after the loss of Larsen A, have set precedent for what to expect elsewhere. Losses by glaciers that fed the Larsen B, such as Crane Glacier, are likely to continue.

Scambos and a team of colleagues have now placed instruments on glaciers just south of the area where the shelves disintegrated, anticipating that further warming will lead to further glacier speed-ups. The instruments and new aircraft overflights will provide further insight into shelf break-up and the onset of ice acceleration.

Wind Matters

Further south is West Antarctica's Pine Island Glacier, another site of major ice loss presently draining more than 19 cubic miles of ice per year from the West Antarctic Ice Sheet. It continues to deteriorate rapidly and scientists want to know why.

By combining satellite and airborne data, Bob Bindschadler, a glaciologist with the Goddard Earth Sciences and Technology Center at NASA's Goddard Space Flight Center in Greenbelt, Md., has successfully gained more insight into interactions between the atmosphere, ocean and ice even though the data can’t reveal these connections directly.

Bindschadler and colleagues looked at images from the Landsat satellite and spotted a series of large surface undulations on the ice shelf. Next they matched the undulations with the timing of warm water pulses in the waters adjacent to the ice shelf. When surface winds are strong, they stir the Southern Ocean and lift the warm water onto the continental shelf where the additional heat contributes to melt.

Airborne data showed the ice shelf was up to 150 meters (492 feet) thinner when the warmer water was present, allowing Bindschadler’s team to establish a direct link between the rate of ice shelf melting and atmospheric wind speed. When the team accounted for the heat coming in and the ice lost, they concluded that only 22 percent of the heat is used in melting. Whether the remaining heat might melt additional ice is unknown, but it is clear that the atmospheric circulation has a strong role on the future of the ice shelf and the fate of the ice sheet inland. Stronger winds would lead to an acceleration of ice loss; weaker winds would have a stabilizing effect.

"In short, ice shelves are affected by what winds are doing," Bindschadler said. "As Antarctic Circumpolar winds continue to increase, ice shelves are at increasing risk."

Sunday, December 12, 2010

Enjoy The Best Meteor Shower of The Year


Baby, it's cold outside -- but you can still enjoy the best meteor shower of the year. The 2010 Geminid meteor shower promises to be lively, with realistic viewing rates of 50-80 meteors per hour and potential peaks reaching 120 meteors per hour. Anytime between Dec. 12-16 is a valid window for Geminid-watching, but the night of Dec. 13-14 is the anticipated peak.

About the Chats

You have two opportunities to learn more about the Geminids from meteor experts based at NASA's Marshall Space Flight Center. On Monday, Dec. 13 from 3:00 to 4:00 p.m. EST, meteor experts Danielle Moser and Rhiannon Blaauw will answer your questions, then you can stay "up all night" to observe the Geminids with NASA astronomer Bill Cooke. Have the coffee ready, then join them online from 11:00 p.m. to 5:00 a.m. EST as the Geminids peak in the skies over Earth.

Joining the chats is easy. Simply return to this page a few minutes before each of the chat start times list above. The chat module will appear at the bottom of this page. After you log in, wait for the chat module to be activated, then ask your questions. Here's to a spectacular viewing!

Live Camera Viewing of the Geminids

December can be an uncertain month for weather, but clouds and meteor-watching don't mix. To assist in the weather-workaround, NASA and meteor-observing partners are working on a network of live Web cameras that will watch the skies from different locations. Links for the live feeds will be available on this page on the night of Dec. 13-14 -- just in case your local weather is uncooperative or you decide not to brave the chilly December evening.

More About the Geminids

Geminids are pieces of debris from an object called 3200 Phaethon. Long thought to be an asteroid, Phaethon is now classified as an extinct comet. Basically it is the rocky skeleton of a comet that lost its ice after too many close encounters with the sun. Earth runs into a stream of debris from 3200 Phaethon every year in mid-December, causing meteors to fly from the constellation Gemini. When the Geminids first appeared in the late 19th century, shortly before the U.S. Civil War, the shower was weak and attracted little attention. There was no hint that it would ever become a major display.

WASP-12b is The First Carbon-Rich Planet


Astronomers have discovered that a huge, searing-hot planet orbiting another star is loaded with an unusual amount of carbon. The planet, a gas giant named WASP-12b, is the first carbon-rich world ever observed. The discovery was made using NASA's Spitzer Space Telescope, along with previously published ground-based observations.

"This planet reveals the astounding diversity of worlds out there," said Nikku Madhusudhan of the Massachusetts Institute of Technology, Cambridge, lead author of a report in the Dec. 9 issue of the journal Nature. "Carbon-rich planets would be exotic in every way -- formation, interiors and atmospheres."

It's possible that WASP-12b might harbor graphite, diamond, or even a more exotic form of carbon in its interior, beneath its gaseous layers. Astronomers don't currently have the technology to observe the cores of exoplanets, or planets orbiting stars beyond our sun, but their theories hint at these intriguing possibilities.

The research also supports theories that carbon-rich rocky planets much less massive than WASP-12b could exist around other stars. Our Earth has rocks like quartz and feldspar, which are made of silicon and oxygen plus other elements. A carbon-rich rocky planet could be a very different place.

"A carbon-dominated terrestrial world could have lots of pure carbon rocks, like diamond or graphite, as well as carbon compounds like tar," said Joseph Harrington of the University of Central Florida, in Orlando, who is the principal investigator of the research.

Carbon is a common component of planetary systems and a key ingredient of life on Earth. Astronomers often measure carbon-to-oxygen ratios to get an idea of a star's chemistry. Our sun has a carbon-to-oxygen ratio of about one to two, which means it has about half as much carbon as oxygen. None of the planets in our solar system is known to have more carbon than oxygen, or a ratio of one or greater. However, this ratio is unknown for Jupiter, Saturn, Uranus, and Neptune. Unlike WASP-12b, these planets harbor water -- the main oxygen carrier -- deep inside their atmospheres, making it hard to detect.

WASP-12b is the first planet ever to have its carbon-to-oxygen ratio measured at greater than one (the actual ratio is most likely between one and two). This means the planet has excess carbon, some of which is in the form of atmospheric methane.

"When the relative amount of carbon gets that high, it's as though you flip a switch, and everything changes," said Marc Kuchner, an astronomer at NASA Goddard Space Flight Center, Greenbelt, Md., who helped develop the theory of carbon-rich rocky planets but is not associated with the study. "If something like this had happened on Earth, your expensive engagement ring would be made of glass, which would be rare, and the mountains would all be made of diamonds."

Madhusudhan, Harrington and colleagues used Spitzer to observe WASP-12b as it slipped behind its star, in a technique known as secondary eclipse, which was pioneered for exoplanets by Spitzer. These data were combined with previously published observations taken from the ground with the Canada-France-Hawaii Telescope at Mauna Kea, Hawaii. Madhusudhan used the data to conduct a detailed atmospheric analysis, revealing chemicals such as methane and carbon monoxide in the planet's atmosphere.

WASP-12b derives its name from the consortium that found it, the Wide Angle Search for Planets. It is 1.4 times as massive as Jupiter and located roughly 1,200 light-years away from Earth. This blistering world whips around its star in a little over a day, with one side always facing the star. It is so close to its star that the star's gravity stretches the planet into an egg-like shape. What's more, the star's gravity is siphoning mass off the planet into a thin disk that orbits around with it.

The Spitzer data also reveal more information about WASP-12b's temperature. The world was already known to be one of the hottest exoplanets found so far; the new observations indicate that the side that faces the star is 2,600 Kelvin, or 4,200 degrees Fahrenheit. That's more than hot enough to melt steel.

Monday, December 06, 2010

Microorganisms able to thrive and reproduce using the toxic chemical


NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.

Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.

"The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. "As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it."

This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth. The research is published in this week's edition of Science Express.

Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur are the six basic building blocks of all known forms of life on Earth. Phosphorus is part of the chemical backbone of DNA and RNA, the structures that carry genetic instructions for life, and is considered an essential element for all living cells.

Phosphorus is a central component of the energy-carrying molecule in all cells (adenosine triphosphate) and also the phospholipids that form all cell membranes. Arsenic, which is chemically similar to phosphorus, is poisonous for most life on Earth. Arsenic disrupts metabolic pathways because chemically it behaves similarly to phosphate.

"We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new -- building parts of itself out of arsenic," said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team's lead scientist. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"

The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms' vital biochemical machinery, such as DNA, proteins and the cell membranes. A variety of sophisticated laboratory techniques was used to determine where the arsenic was incorporated.

The team chose to explore Mono Lake because of its unusual chemistry, especially its high salinity, high alkalinity, and high levels of arsenic. This chemistry is in part a result of Mono Lake's isolation from its sources of fresh water for 50 years.

The results of this study will inform ongoing research in many areas, including the study of Earth's evolution, organic chemistry, biogeochemical cycles, disease mitigation and Earth system research. These findings also will open up new frontiers in microbiology and other areas of research.

"The idea of alternative biochemistries for life is common in science fiction," said Carl Pilcher, director of the NASA Astrobiology Institute at the agency's Ames Research Center in Moffett Field, Calif. "Until now a life form using arsenic as a building block was only theoretical, but now we know such life exists in Mono Lake."

The research team included scientists from the U.S. Geological Survey, Arizona State University in Tempe, Ariz., Lawrence Livermore National Laboratory in Livermore, Calif., Duquesne University in Pittsburgh, Penn., and the Stanford Synchroton Radiation Lightsource in Menlo Park, Calif.

NASA's Astrobiology Program in Washington contributed funding for the research through its Exobiology and Evolutionary Biology program and the NASA Astrobiology Institute. NASA's Astrobiology Program supports research into the origin, evolution, distribution, and future of life on Earth.

Thursday, December 02, 2010

A team of astronomers made the first characterizations of a super-Earth's atmosphere


A team of astronomers, including two NASA Sagan Fellows, has made the first characterizations of a super-Earth's atmosphere, by using a ground-based telescope. A super-Earth is a planet up to three times the size of Earth and weighing up to 10 times as much. The findings, reported in the Dec. 2 issue of the journal Nature, are a significant milestone toward eventually being able to probe the atmospheres of Earth-like planets for signs of life.

The team determined the planet, GJ 1214b, is either blanketed with a thin layer of water steam or surrounded by a thick layer of high clouds. If the former, the planet itself would have an icy composition. If the latter, the planet would be rocky or similar to the composition of Neptune, though much smaller.

"This is the first super-Earth known to have an atmosphere," said Jacob Bean, a NASA Sagan Fellow and astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "But even with these new measurements, we can't say yet what that atmosphere is made of. This world is being very shy and veiling its true nature from us."

GJ 1214b, first discovered in December 2009, is 2.7 times the size of Earth and 6.5 times as massive. Previous observations of the planet's size and mass demonstrated it has a low density for its size, leading astronomers to conclude the planet is some kind of solid body with an atmosphere.

The planet orbits close to its dim star, at a distance of 0.014 astronomical units. An astronomical unit is the distance between Earth and the sun, approximately 93 million miles. GJ 1214b circles too close to its star to be habitable by any life forms.

Bean and his team observed infrared light as the planet crossed in front of its star. During such transits, the star's light filters through the atmosphere. Gases absorb the starlight at particular wavelengths, leaving behind chemical fingerprints detectable from Earth. This same type of technique has been used to study the atmospheres of distant "hot Jupiters," or Jupiter-like planets orbiting close to their stars, and found gases like hydrogen, methane and sodium vapor.

In the case of the super-Earth, no chemical fingerprints were detected; however, this doesn't mean there are no chemicals present. Instead, this information ruled out some possibilities for GJ 1214b's atmosphere, and narrowed the scope to either an atmosphere of water steam or high clouds. Astronomers believe it's more likely the atmosphere is too thin around the planet to let enough light filter through and reveal chemical fingerprints.

"A steamy atmosphere would have to be very dense – about one-fifth water vapor by volume -- compared to our Earth, with an atmosphere that's four-fifths nitrogen and one-fifth oxygen with only a touch of water vapor," Bean said. "During the next year, we should have some solid answers about what this planet is truly like."

The team, which included Bean's co-authors -- Eliza Miller-Ricci Kempton, a NASA Sagan Fellow at the University of California in Santa Cruz, and Derek Homeier of the Institute for Astrophysics in Gottingen, Germany -- examined GJ 1214b using the ground-based Very Large Telescope at Paranal Observatory in Chile.

"This is an important step forward, narrowing our understanding of the atmosphere of this planet," said NASA Exoplanet Exploration Program Scientist Douglas Hudgins at NASA Headquarters in Washington. "Bizarre worlds like this make exoplanet science one of the most compelling areas in astrophysics today."

The Sagan Fellowship Program is administered by the NASA Exoplanet Science Institute at the California Institute of Technology in Pasadena. Its purpose is to advance the scientific and technical goals of NASA's Exoplanet Exploration Program. The program is managed for NASA by the Jet Propulsion Laboratory in Pasadena, Calif. Caltech manages JPL for NASA.