Fastest Rotating Star Found in Neighboring Galaxy

This artist's concept pictures the fastest rotating star found to date. The massive, bright young star, called VFTS 102, rotates at a million miles per hour, or 100 times faster than our sun does. Centrifugal forces from this dizzying spin rate have flattened the star into an oblate shape and spun off a disk of hot plasma, seen edge on in this view from a hypothetical planet. The star may have "spun up" by accreting material from a binary companion star. The rapidly evolving companion later exploded as a supernova. The whirling star lies 160,000 light-years away in the Large Magellanic Cloud, a satellite galaxy of the Milky Way.

Source : NASA
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NASA Discovers First Earth-size Planets beyond Our Solar System

NASA's Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet's surface, but they are the smallest exoplanets ever confirmed around a star like our sun.

The discovery marks the next important milestone in the ultimate search for planets like Earth. The new planets are thought to be rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth. Kepler-20f is a bit larger than Earth, measuring 1.03 times its radius. Both planets reside in a five-planet system called Kepler-20, approximately 1,000 light-years away in the constellation Lyra.

Kepler-20e orbits its parent star every 6.1 days and Kepler-20f every 19.6 days. These short orbital periods mean very hot, inhospitable worlds. Kepler-20f, at 800 degrees Fahrenheit, is similar to an average day on the planet Mercury. The surface temperature of Kepler-20e, at more than 1,400 degrees Fahrenheit, would melt glass.

“The primary goal of the Kepler mission is to find Earth-sized planets in the habitable zone," said Francois Fressin of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., lead author of a new study published in the journal Nature. "This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them.”

The Kepler-20 system includes three other planets that are larger than Earth but smaller than Neptune. Kepler-20b, the closest planet, Kepler-20c, the third planet, and Kepler-20d, the fifth planet, orbit their star every 3.7, 10.9 and 77.6 days. All five planets have orbits lying roughly within Mercury's orbit in our solar system. The host star belongs to the same G-type class as our sun, although it is slightly smaller and cooler.

The system has an unexpected arrangement. In our solar system, small, rocky worlds orbit close to the sun and large, gaseous worlds orbit farther out. In comparison, the planets of Kepler-20 are organized in alternating size: large, small, large, small and large.

"The Kepler data are showing us some planetary systems have arrangements of planets very different from that seen in our solar system," said Jack Lissauer, planetary scientist and Kepler science team member at NASA's Ames Research Center in Moffett Field, Calif. "The analysis of Kepler data continues to reveal new insights about the diversity of planets and planetary systems within our galaxy."

Scientists are not certain how the system evolved but they do not think the planets formed in their existing locations. They theorize the planets formed farther from their star and then migrated inward, likely through interactions with the disk of material from which they originated. This allowed the worlds to maintain their regular spacing despite alternating sizes.

The Kepler space telescope detects planets and planet candidates by measuring dips in the brightness of more than 150,000 stars to search for planets crossing in front, or transiting, their stars. The Kepler science team requires at least three transits to verify a signal as a planet.

The Kepler science team uses ground-based telescopes and the Spitzer Space Telescope to review observations on planet candidates the spacecraft finds. The star field Kepler observes in the constellations Cygnus and Lyra can be seen only from ground-based observatories in spring through early fall. The data from these other observations help determine which candidates can be validated as planets.

To validate Kepler-20e and Kepler-20f, astronomers used a computer program called Blender, which runs simulations to help rule out other astrophysical phenomena masquerading as a planet.

On Dec. 5 the team announced the discovery of Kepler-22b in the habitable zone of its parent star. It is likely to be too large to have a rocky surface. While Kepler-20e and Kepler-20f are Earth-size, they are too close to their parent star to have liquid water on the surface.

"In the cosmic game of hide and seek, finding planets with just the right size and just the right temperature seems only a matter of time," said Natalie Batalha, Kepler deputy science team lead and professor of astronomy and physics at San Jose State University. "We are on the edge of our seats knowing that Kepler's most anticipated discoveries are still to come."

NASA's Ames Research Center in Moffett Field, Calif., manages Kepler's ground system development, mission operations and science data analysis. JPL managed the Kepler mission's development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The Space Telescope Science Institute in Baltimore archives hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

Source : NASA

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New Expedition 30 Crew Members Launch to Station

Expedition 30 Flight Engineers Don Pettit, Oleg Kononenko and Andre Kuipers launched at 8:16 a.m. EST on Wednesday, Dec. 21 (7:16 p.m. local time) from the Baikonur Cosmodrome in Kazakhstan. The three new International Space Station crew members launched in their Soyuz TMA-03M spacecraft beginning a two-day trip to the orbiting outpost.

They are set to dock to the station's Rassvet mini-research module about 10:22 a.m. on Friday, Dec. 23. Expedition 30 Commander Dan Burbank and Flight Engineers Anton Shkaplerov and Anatoly Ivanishin will welcome their new crewmates aboard the station a little while later when they open the hatches about 1 p.m.

Pettit, Kononenko and Kuipers are scheduled to live and work aboard the orbiting laboratory until May. They will become members of the Expedition 31 crew under the command of Kononenko when Burbank, Shkaplerov and Ivanishin undock in their Soyuz TMA-22 spacecraft in March.

Source : NASA

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NASA Telescopes Help Find Rare Galaxy at Dawn of Time

Astronomers using NASA's Spitzer and Hubble space telescopes have discovered that one of the most distant galaxies known is churning out stars at a shockingly high rate. The blob-shaped galaxy, called GN-108036, is the brightest galaxy found to date at such great distances.

The galaxy, which was discovered and confirmed using ground-based telescopes, is 12.9 billion light-years away. Data from Spitzer and Hubble were used to measure the galaxy's high star production rate, equivalent to about 100 suns per year. For reference, our Milky Way galaxy is about five times larger and 100 times more massive than GN-108036, but makes roughly 30 times fewer stars per year.

"The discovery is surprising because previous surveys had not found galaxies this bright so early in the history of the universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "Perhaps those surveys were just too small to find galaxies like GN-108036. It may be a special, rare object that we just happened to catch during an extreme burst of star formation."

The international team of astronomers, led by Masami Ouchi of the University of Tokyo, Japan, first identified the remote galaxy after scanning a large patch of sky with the Subaru Telescope atop Mauna Kea in Hawaii. Its great distance was then carefully confirmed with the W.M. Keck Observatory, also on Mauna Kea.

"We checked our results on three different occasions over two years, and each time confirmed the previous measurement," said Yoshiaki Ono of the University of Tokyo, lead author of a new paper reporting the findings in the Astrophysical Journal.

GN-108036 lies near the very beginning of time itself, a mere 750 million years after our universe was created 13.7 billion years ago in an explosive "Big Bang." Its light has taken 12.9 billion years to reach us, so we are seeing it as it existed in the very distant past.

Astronomers refer to the object's distance by a number called its "redshift," which relates to how much its light has stretched to longer, redder wavelengths due to the expansion of the universe. Objects with larger redshifts are farther away and are seen further back in time. GN-108036 has a redshift of 7.2. Only a handful of galaxies have confirmed redshifts greater than 7, and only two of these have been reported to be more distant than GN-108036.

Infrared observations from Spitzer and Hubble were crucial for measuring the galaxy's star-formation activity. Astronomers were surprised to see such a large burst of star formation because the galaxy is so small and from such an early cosmic era. Back when galaxies were first forming, in the first few hundreds of millions of years after the Big Bang, they were much smaller than they are today, having yet to bulk up in mass.

During this epoch, as the universe expanded and cooled after its explosive start, hydrogen atoms permeating the cosmos formed a thick fog that was opaque to ultraviolet light. This period, before the first stars and galaxies had formed and illuminated the universe, is referred to as the "dark ages." The era came to an end when light from the earliest galaxies burned through, or "ionized," the opaque gas, causing it to become transparent. Galaxies similar to GN-108036 may have played an important role in this event.

"The high rate of star formation found for GN-108036 implies that it was rapidly building up its mass some 750 million years after the Big Bang, when the universe was only about five percent of its present age," said Bahram Mobasher, a team member from the University of California, Riverside. "This was therefore a likely ancestor of massive and evolved galaxies seen today."

 Source : NASA

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NASA 'Smart SPHERES' Tested Successfully on International Space Station

In November, a free-flying robot on the International Space Station successfully gathered and delivered motion data to its astronaut handler for the first time via a new smartphone controller.

The Human Exploration Telerobotics project, one of NASA's new, high-value Technology Demonstration Missions, equipped the compact, free-flying satellites -- known as Synchronized Position Hold, Engage, Reorient Experimental Satellites, or SPHERES -- with a Samsung Nexus S™ handset that features Google’s open-source Android™ platform.

Each volleyball-sized SPHERES has its own onboard power, propulsion, computing and navigational software. Adding the smartphone transforms the satellite into a free-flying robot, or "Smart SPHERES" -- complete with a compact, low-power, low-cost embedded computer and built-in cameras and sensors to enhance and expand robotic operations.

Minor modifications were made to the smartphones, including removing the GSM cellular communications chip to avoid interference with station electronics, and replacing the standard lithium-ion battery with AA alkaline batteries. Otherwise, the smartphone is identical to the off-the-shelf consumer device. 

The ongoing experiment demonstrates how the Smart SPHERES can serve as remotely operated assistants for astronauts in space. In coming months, these compact assistants will conduct interior station surveys and inspections, capturing mobile camera images and video. NASA also plans to simulate external free-flight excursions and in time will test whether the robots can handle other, more challenging tasks.

"The tests that we are conducting with Smart SPHERES will help NASA make better use of robots as assistants to and versatile support for human explorers -- in Earth orbit or on long missions to other worlds and new destinations," said Terry Fong, project manager of the Human Exploration Telerobotics project and Director of the Intelligent Robotics Group at NASA's Ames Research Center in Moffett Field, Calif.

The Nexus S phone is the first commercial smartphone certified by NASA for use on the space station. Each smartphone is connected to a SPHERES free-flyer via a cable. A wireless network connection (Wi-Fi) to the space station's computers provides the data path to the ground. NASA anticipates using other types of smartphones on the station in the future.

Source : NASA

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A 'Rose' Made of Galaxies

In celebration of the twenty-firstt anniversary of the Hubble Space Telescope's deployment in April 2011, astronomers at the Space Telescope Science Institute pointed Hubble's eye to an especially photogenic group of interacting galaxies called Arp 273.

The larger of the spiral galaxies, known as UGC 1810, has a disk that is tidally distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy below it, known as UGC 1813. A swath of blue jewels across the top is the combined light from clusters of intensely bright and hot young blue stars. These massive stars glow fiercely in ultraviolet light.

The smaller, nearly edge-on companion shows distinct signs of intense star formation at its nucleus, perhaps triggered by the encounter with the companion galaxy.

A series of uncommon spiral patterns in the large galaxy is a tell-tale sign of interaction. The large, outer arm appears partially as a ring, a feature seen when interacting galaxies actually pass through one another. This suggests that the smaller companion actually dived deep, but off-center, through UGC 1810. The inner set of spiral arms is highly warped out of the plane with one of the arms going behind the bulge and coming back out the other side. How these two spiral patterns connect is still not precisely known.

The interaction was imaged on Dec. 17, 2010, with Hubble's Wide Field Camera 3 (WFC3).

This Hubble image is a composite of data taken with three separate filters on WFC3 that allow a broad range of wavelengths covering the ultraviolet, blue and red portions of the spectrum.

Source NASA

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NASA Mars-Bound Rover Begins Research in Space

NASA's car-sized Curiosity rover has begun monitoring space radiation during its 8-month trip from Earth to Mars. The research will aid in planning for future human missions to the Red Planet.

Curiosity launched on Nov. 26 from Cape Canaveral, Fla., aboard the Mars Science Laboratory. The rover carries an instrument called the Radiation Assessment Detector (RAD) that monitors high-energy atomic and subatomic particles from the sun, distant supernovas and other sources.

   These particles constitute radiation that could be harmful to any microbes or astronauts in space or on Mars. The rover also will monitor radiation on the surface of Mars after its August 2012 landing.

"RAD is serving as a proxy for an astronaut inside a spacecraft on the way to Mars," said Don Hassler, RAD's principal investigator from the Southwest Research Institute in Boulder, Colo. "The instrument is deep inside the spacecraft, the way an astronaut would be. Understanding the effects of the spacecraft on the radiation field will be valuable in designing craft for astronauts to travel to Mars."

Previous monitoring of energetic-particle radiation in space has used instruments at or near the surface of various spacecraft. The RAD instrument is on the rover inside the spacecraft and shielded by other components of Mars Science Laboratory, including the aeroshell that will protect the rover during descent through the upper atmosphere of Mars.

 Spacecraft structures, while providing  shielding, also can contribute to secondary   particles generated when high-energy particles strike the spacecraft. In some circumstances, secondary particles could be more hazardous than primary ones.

These first measurements mark the start of the science return from a mission that will use 10 instruments on Curiosity to assess whether Mars' Gale Crater could be or has been favorable for microbial life.

"While Curiosity will not look for signs of life on Mars, what it might find could be a game-changer about the origin and evolution of life on Earth and elsewhere in the universe," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. "One thing is certain: The rover's discoveries will provide critical data that will impact human and robotic planning and research for decades."

Source : NASA

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Satellite Data Shows that Kirtland’s Warblers Prefer Forests after Fire

Kirtland’s warblers are an endangered species of lightweight little birds with bright yellow-bellies that summer in North America and winter in the Bahamas. But be it their winter or their summer home, a new study using data from NASA-built Landsat satellites shows that these warblers like to live in young forests and often forests that have been on fire.

The U.S. Fish and Wildlife Service listed Kirtland’s warblers as endangered in 1967 after a startling decline of over 50 percent in less than ten years. The little birds prefer to nest on the ground amidst large areas of relatively young jack pine trees, and these trees need fire to reproduce. When fires were dramatically suppressed in the 1960s across northern Michigan, Wisconsin and southern Ontario, the warbler’s habitat became scarce.
After an intensive recovery program that focused both on combating invasive cowbirds and managing controlled forest burns, and thus creating warbler-friendly jack pine habitat, the Kirtland’s warbler made an impressive comeback. By 1995 their numbers had tripled.
But those extensive efforts only occurred at the Kirtland’s summer home, so a team of researchers reviewed the conditions of many a warbler’s winter home – the Bahamian island of Eleuthera. They did this by painstakingly putting together Landsat data to create cloud-free images of the isle’s forest cover.

Tropical islands typically have cloud cover, so the team compiled many Landsat images with scenes where the clouds were in different places into one image of clear forest, said Eileen Helmer. She’s a member of the Landsat Science Team for the U. S. Geological Survey (USGS) and works for the U.S. Department of Agriculture Forest Service International Institute of Tropical Forestry.
The researchers did this not just once, but ten times, obtaining a record that spans a 30-year time period. According to Helmer, this allows them to tell how long it had been since the forest was last disturbed by fire, crops or grazing.

What the scientists discovered was that, like in their summer homes, Kirtland’s warblers are found in young forests. On Eleuthera, these forests only occur after a disturbance of some sort – like fire, clearing for agriculture, or grazing. And grazing turns out to be a disturbance the warbler can live with just fine. Old forest whose underbrush has been munched on by goats provides the most suitable habitat for warblers, said Helmer.

The results, published in this month's issue of Biotropica, suggest that goat grazing stunts the forest regrowth, so that the tree height doesn’t exceed the height beyond which important fruit-bearing forage tree species are shaded out by taller woody species. Helmer said that understanding how and where the warbler's winter habitat occurs will help conservation efforts in the Bahamas.

Helmer said that a unique feature of warbler’s winter habitat is that the age of this forest correlates very strongly with its height. By tracking the age of the forest after a disturbance, she and her team determined forest height at different times. Helmer said they used image time-series data from Landsat and the Advance Land Imager (ALI) sensor aboard the Earth-Observing 1 (EO-1) satellite to essentially ‘stack’ many images over time. This project is the first time that forest height profiles have been successfully mapped by satellite imagery at a medium resolution that shows a broad area but still resolves human impacts on the land. As in the warbler case, understanding how a forest is put together in three dimensions is important for ecological studies. Helmer adds that this tool may be applied elsewhere around the world due to Landsat’s global coverage and policy of free access to data. Helmer will discuss mapping forest height at the American Geophysical Union conference in San Francisco on Friday, Dec. 9.

Source: NASA
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NASA Mars-Bound Rover Begins Research in Space

NASA's car-sized Curiosity rover has begun monitoring space radiation during its 8-month trip from Earth to Mars. The research will aid in planning for future human missions to the Red Planet.

Curiosity launched on Nov. 26 from Cape Canaveral, Fla., aboard the Mars Science Laboratory. The rover carries an instrument called the Radiation Assessment Detector (RAD) that monitors high-energy atomic and subatomic particles from the sun, distant supernovas and other sources.

These particles constitute radiation that could be harmful to any microbes or astronauts in space or on Mars. The rover also will monitor radiation on the surface of Mars after its August 2012 landing.

"RAD is serving as a proxy for an astronaut inside a spacecraft on the way to Mars," said Don Hassler, RAD's principal investigator from the Southwest Research Institute in Boulder, Colo. "The instrument is deep inside the spacecraft, the way an astronaut would be. Understanding the effects of the spacecraft on the radiation field will be valuable in designing craft for astronauts to travel to Mars."

Previous monitoring of energetic-particle radiation in space has used instruments at or near the surface of various spacecraft. The RAD instrument is on the rover inside the spacecraft and shielded by other components of Mars Science Laboratory, including the aeroshell that will protect the rover during descent through the upper atmosphere of Mars.

Spacecraft structures, while providing shielding, also can contribute to secondary particles generated when high-energy particles strike the spacecraft. In some circumstances, secondary particles could be more hazardous than primary ones.

These first measurements mark the start of the science return from a mission that will use 10 instruments on Curiosity to assess whether Mars' Gale Crater could be or has been favorable for microbial life.

"While Curiosity will not look for signs of life on Mars, what it might find could be a game-changer about the origin and evolution of life on Earth and elsewhere in the universe," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. "One thing is certain: The rover's discoveries will provide critical data that will impact human and robotic planning and research for decades."

As of 9 a.m. PST (noon EST) on Dec. 14, the spacecraft will have traveled 31.9 million miles (51.3 million kilometers) of its 352-million-mile (567-million-kilometer) flight to Mars. The first trajectory correction maneuver during the trip is being planned for mid-January.

Source: NASA
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LRO Observes Final Lunar Eclipse of the Year

12.09.11

 

Orbiting 31 miles above the lunar surface, NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft will get a "front-row seat" to the total lunar eclipse on Dec. 10, 2011.

LRO's Diviner instrument will record how quickly targeted areas on the moon's day side cool off during the eclipse. The degree of cooling is dependent on factors such as how rocky the surface is, how densely packed the soil is, and its mineral composition. By studying the lunar surface during the eclipse, scientists can learn even more about our nearest celestial neighbor.From beginning to end, the eclipse will last from 11:33 UT (6:33 a.m. EST, 3:33 a.m. PST) to 17:30 UT (12:30 p.m. EST, 9:30 a.m. PST). Totality, the time when Earth's shadow completely covers the moon, will last 51 minutes. All of the United States will see some portion of the eclipse. The West Coast will have a more complete view of this particular eclipse.

The West Coast will see totality as the moon sets and the sun rises. For West Coast viewers, the eclipse begins at 3:33 a.m. PST. The peak, when the moon is a deep red, occurs at 6:30 a.m. PST.

For East Coast residents, the only stage of the eclipse that will be visible is the earliest portion when the moon begins to enter Earth's shadow. This dimming is very slight and may be difficult to see.

When the moon passes through the Earth's shadow, it causes the moon to look very unusual for a short period of time. This event is called a lunar eclipse, and it occurs roughly twice a year.The moon takes on this new color because sunlight is still able to pass through Earth's atmosphere and cast a glow on the moon. Our atmosphere filters out most of the blue colored light, leaving the red and orange hues that we see during a lunar eclipse. If there are additional dust particles in the atmosphere, the moon will appear to be a darker shade of red.

Source : NASA
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NASA Mars Rover Finds Mineral Vein Deposited by Water

NASA's Mars Exploration Rover Opportunity has found bright veins of a mineral, apparently gypsum, deposited by water. Analysis of the vein will help improve understanding of the history of wet environments on Mars.

"This tells a slam-dunk story that water flowed through underground fractures in the rock," said Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for Opportunity. "This stuff is a fairly pure chemical deposit that formed in place right where we see it. That can't be said for other gypsum seen on Mars or for other water-related minerals Opportunity has found. It's not uncommon on Earth, but on Mars, it's the kind of thing that makes geologists jump out of their chairs."

The latest findings by Opportunity were presented Wednesday at the American Geophysical Union's conference in San Francisco.

The vein examined most closely by Opportunity is about the width of a human thumb (0.4 to 0.8 inch, or 1 to 2 centimeters), 16 to 20 inches (40 to 50 centimeters) long, and protrudes slightly higher than the bedrock on either side of it. Observations by the durable rover reveal this vein and others like it within an apron surrounding a segment of the rim of Endeavour Crater. None like it were seen in the 20 miles (33 kilometers) of crater-pocked plains that Opportunity explored for 90 months before it reached Endeavour, nor in the higher ground of the rim.

Last month, researchers used the Microscopic Imager and Alpha Particle X-ray Spectrometer on the rover's arm and multiple filters of the Panoramic Camera on the rover's mast to examine the vein, which is informally named "Homestake." The spectrometer identified plentiful calcium and sulfur, in a ratio pointing to relatively pure calcium sulfate.

Calcium sulfate can exist in many forms, varying by how much water is bound into the minerals' crystalline structure. The multi-filter data from the camera suggest gypsum, a hydrated calcium sulfate. On Earth, gypsum is used for making drywall and plaster of Paris. Observations from orbit had detected gypsum on Mars previously. A dune field of windblown gypsum on far northern Mars resembles the glistening gypsum dunes in White Sands National Monument in New Mexico.

"It is a mystery where the gypsum sand on northern Mars comes from," said Opportunity science-team member Benton Clark of the Space Science Institute in Boulder, Colo. "At Homestake, we see the mineral right where it formed. It will be important to see if there are deposits like this in other areas of Mars."

The Homestake deposit, whether gypsum or another form of calcium sulfate, likely formed from water dissolving calcium out of volcanic rocks. The calcium combined with sulfur that was either leached from the rocks or introduced as volcanic gas, and it was deposited as calcium sulfate into an underground fracture that later became exposed at the surface.
Throughout Opportunity's long traverse across Mars' Meridiani plain, the rover has driven over bedrock composed of magnesium, iron and calcium sulfate minerals that also indicate a wet environment billions of years ago. The highly concentrated calcium sulfate at Homestake could have been produced in conditions more neutral than the harshly acidic conditions indicated by the other sulfate deposits observed by Opportunity.
"It could have formed in a different type of water environment, one more hospitable for a larger variety of living organisms," Clark said.
Homestake and similar-looking veins appear in a zone where the sulfate-rich sedimentary bedrock of the plains meets older, volcanic bedrock exposed at the rim of Endeavour. That location may offer a clue about their origin.
Opportunity and its rover twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued for years of extended missions and made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit stopped communicating in 2010. Opportunity continues exploring, currently heading to a sun-facing slope on the northern end of the Endeavour rim fragment called "Cape York" to keep its solar panels at a favorable angle during the mission's fifth Martian winter.  

 We want to understand why these veins are in the apron but not out on the plains," said the mission's deputy principal investigator, Ray Arvidson, of Washington University in St. Louis. "The answer may be that rising groundwater coming from the ancient crust moved through material adjacent to Cape York and deposited gypsum, because this material would be relatively insoluble compared with either magnesium or iron sulfates."

Source NASA
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NASA's Kepler Mission Confirms Its First Planet in Habitable Zone of Sun-like Star

 

NASA's Kepler mission has confirmed its first planet in the "habitable zone," the region where liquid water could exist on a planet’s surface. Kepler also has discovered more than 1,000 new planet candidates, nearly doubling its previously known count. Ten of these candidates are near-Earth-size and orbit in the habitable zone of their host star. Candidates require follow-up observations to verify they are actual planets.

The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our sun. The planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets. 
Previous research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.

Previous research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.

"This is a major milestone on the road to finding Earth's twin," said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Kepler's results continue to demonstrate the importance of NASA's science missions, which aim to answer some of the biggest questions about our place in the universe."

Kepler discovers planets and planet candidates by measuring dips in the brightness of more than 150,000 stars to search for planets that cross in front, or "transit," the stars. Kepler requires at least three transits to verify a signal as a planet.

"Fortune smiled upon us with the detection of this planet," said William Borucki, Kepler principal investigator at NASA Ames Research Center at Moffett Field, Calif., who led the team that discovered Kepler-22b. "The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season."

The Kepler science team uses ground-based telescopes and the Spitzer Space Telescope to review observations on planet candidates the spacecraft finds. The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these other observations help determine which candidates can be validated as planets.

Kepler-22b is located 600 light-years away. While the planet is larger than Earth, its orbit of 290 days around a sun-like star resembles that of our world. The planet's host star belongs to the same class as our sun, called G-type, although it is slightly smaller and cooler.

Of the 54 habitable zone planet candidates reported in February 2011, Kepler-22b is the first to be confirmed. This milestone will be published in The Astrophysical Journal.

The Kepler team is hosting its inaugural science conference at Ames Dec. 5-9, announcing 1,094 new planet candidate discoveries. Since the last catalog was released in February, the number of planet candidates identified by Kepler has increased by 89 percent and now totals 2,326. Of these, 207 are approximately Earth-size, 680 are super Earth-size, 1,181 are Neptune-size, 203 are Jupiter-size and 55 are larger than Jupiter.

The findings, based on observations conducted May 2009 to September 2010, show a dramatic increase in the numbers of smaller-size planet candidates.

Kepler observed many large planets in small orbits early in its mission, which were reflected in the February data release. Having had more time to observe three transits of planets with longer orbital periods, the new data suggest that planets one to four times the size of Earth may be abundant in the galaxy.

The number of Earth-size and super Earth-size candidates has increased by more than 200 and 140 percent since February, respectively.

There are 48 planet candidates in their star's habitable zone. While this is a decrease from the 54 reported in February, the Kepler team has applied a stricter definition of what constitutes a habitable zone in the new catalog, to account for the warming effect of atmospheres, which would move the zone away from the star, out to longer orbital periods.

"The tremendous growth in the number of Earth-size candidates tells us that we're honing in on the planets Kepler was designed to detect: those that are not only Earth-size, but also are potentially habitable," said Natalie Batalha, Kepler deputy science team lead at San Jose State University in San Jose, Calif. "The more data we collect, the keener our eye for finding the smallest planets out at longer orbital periods."

NASA's Ames Research Center manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Source : NASA

NASA's Hubble Finds Stellar Life and Death in a Globular Cluster

New NASA Hubble Space Telescope image shows globular cluster NGC 1846, a spherical collection of hundreds of thousands of stars in the outer halo of the Large Magellanic Cloud, a neighboring dwarf galaxy of the Milky Way that can be seen from the southern hemisphere.

Aging bright stars in the cluster glow in intense shades of red and blue. The majority of middle-aged stars, several billions of years old, are whitish in color. A myriad of far distant background galaxies of varying shapes and structure are scattered around the image.

The most intriguing object, however, doesn’t seem to belong in the cluster. It is a faint green bubble near the bottom center of the image. This so-called ‘planetary nebula’ is the aftermath of the death of a star. The burned-out central star can be seen inside the bubble. It is uncertain whether the planetary nebula is a member of NGC 1846, or simply lies along the line of sight to the cluster. Measurements of the motion of the cluster stars and the planetary nebula’s central star suggest it might be a cluster member.

A new NASA Hubble Space Telescope image shows globular cluster NGC 1846, a spherical collection of hundreds of thousands of stars in the outer halo of the Large Magellanic Cloud, a neighboring dwarf galaxy of the Milky Way that can be seen from the southern hemisphere.

Source : NASA