NASA Aids in Characterizing Super-Earth 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.
For more information visit: http://www.nasa.gov/topics/universe/features/exoplanet20101201.html
Thin Air - Cassini Finds Ethereal Atmosphere at Rhea
NASA's Cassini spacecraft has detected a very tenuous atmosphere known as an exosphere, infused with oxygen and carbon dioxide around Saturn's icy moon Rhea. This is the first time a spacecraft has directly captured molecules of an oxygen atmosphere – albeit a very thin one -- at a world other than Earth.
The oxygen appears to arise when Saturn's magnetic field rotates over Rhea. Energetic particles trapped in the planet's magnetic field pepper the moon’s water-ice surface. They cause chemical reactions that decompose the surface and release oxygen. The source of the carbon dioxide is less certain.
Oxygen at Rhea's surface is estimated to be about 5 trillion times less dense than what we have at Earth. But the new results show that surface decomposition could contribute abundant molecules of oxygen, leading to surface densities roughly 100 times greater than the exospheres of either Earth's moon or Mercury. The formation of oxygen and carbon dioxide could possibly drive complex chemistry on the surfaces of many icy bodies in the universe.
"The new results suggest that active, complex chemistry involving oxygen may be quite common throughout the solar system and even our universe," said lead author Ben Teolis, a Cassini team scientist based at Southwest Research Institute in San Antonio. "Such chemistry could be a prerequisite for life. All evidence from Cassini indicates that Rhea is too cold and devoid of the liquid water necessary for life as we know it."
Releasing oxygen through surface irradiation could help generate conditions favorable for life at an icy body other than Rhea that has liquid water under the surface, Teolis said. If the oxygen and carbon dioxide from the surface could somehow get transported down to a sub-surface ocean, that would provide a much more hospitable environment for more complex compounds and life to form. Scientists are keen to investigate whether life on icy moons with an ocean is possible, though they have not yet detected it.
The tenuous atmosphere with oxygen and carbon dioxide makes Rhea, Saturn's second largest moon, unique in the Saturnian system. Titan has a thick nitrogen-methane atmosphere, but very little carbon dioxide and oxygen.
"Rhea is turning out to be much more interesting than we had imagined," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The Cassini finding highlights the rich diversity of Saturn’s moons and gives us clues on how they formed and evolved."
Scientists had suspected Rhea could have a thin atmosphere with oxygen and carbon dioxide, based on remote observations of Jupiter's icy moons by NASA's Galileo spacecraft and Hubble Space Telescope. Other Cassini observations detected oxygen escaping from icy Saturn ring particles after ultraviolet bombardment. But Cassini was able to detect oxygen and carbon dioxide in the exosphere directly because of how close it flew to Rhea – 101 kilometers, or 63 miles – and its special suite of instruments.
In the new study, scientists combined data from Cassini's ion and neutral mass spectrometer and the Cassini plasma spectrometer during flybys on Nov. 26, 2005, Aug. 30, 2007, and March 2, 2010. The ion and neutral mass spectrometer "tasted" peak densities of oxygen of around 50 billion molecules per cubic meter (1 billion molecules per cubic foot). It detected peak densities of carbon dioxide of around 20 billion molecules per cubic meter (about 600 million molecules per cubic foot).
The plasma spectrometer saw clear signatures of flowing streams of positive and negative ions, with masses that corresponded to ions of oxygen and carbon dioxide.
"How exactly the carbon dioxide is released is still a puzzle," said co-author Geraint Jones, a Cassini team scientist based at University College London in the U.K. "But with Cassini's diverse suite of instruments observing Rhea from afar, as well as sniffing the gas surrounding it, we hope to solve the puzzle."
The carbon dioxide may be the result of "dry ice" trapped from the primordial solar nebula, as is the case with comets, or it may be due to similar irradiation processes operating on the organic molecules trapped in the water ice of Rhea. The carbon dioxide could also come from carbon-rich materials deposited by tiny meteors that bombarded Rhea's surface.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The ion and neutral mass spectrometer team and the Cassini plasma spectrometer team are based at Southwest Research Institute, San Antonio.
For more information visit: http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20101126.html
Cassini Back to Normal, Ready for Enceladus
Cassini Mission Status
NASA's Cassini spacecraft resumed normal operations today, Nov. 24. All science instruments have been turned back on, the spacecraft is properly configured and Cassini is in good health. Mission managers expect to get a full stream of data during next week's flyby of the Saturnian moon Enceladus.
Cassini went into safe mode on Nov. 2, when one bit flipped in the onboard command and data subsystem computer. The bit flip prevented the computer from registering an important instruction, and the spacecraft, as programmed, went into the standby mode. Engineers have traced the steps taken by the computer during that time and have determined that all spacecraft responses were proper, but still do not know why the bit flipped.
The flyby on Nov. 30 will bring Cassini to within about 48 kilometers (30 miles) of the surface of Enceladus. At 61 degrees north latitude, this encounter and its twin three weeks later at the same altitude and latitude, are the closest Cassini will come to the northern hemisphere surface of Enceladus during the extended Solstice mission. (Cassini's closest-ever approach to the surface occurred in October 2008, when it dipped to an altitude of 25 kilometers, or 16 miles.)
During the closest part of the Nov. 30 flyby, Cassini's radio science subsystem will make gravity measurements. The results will be compared with those from an earlier flyby of the Enceladus south pole to understand the moon's interior structure better. Cassini's fields and particles instruments will sample the charged particle environment around Enceladus. Other instruments will capture images in visible light and other parts of the light spectrum after Cassini makes its closest approach.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C.
For more information visit: http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20101124.html
Scientists Chosen to Help on Venus Climate Orbiter
NASA has established a Venus Climate Orbiter Participating Scientist Program to complement scientific return of the Japan Aerospace Exploration Agency (JAXA)-led Venus Climate Orbiter, or "Akatsuki" mission. The Participating Scientist Program will fund two scientists in residence to live in Japan and five Participating Scientists to conduct joint research with the Venus Climate Orbiter science team.
Based on peer-reviewed proposals submitted to NASA, NASA and JAXA are pleased to announce the following joint selections of U.S. Participating Scientists:
Participating Scientist in Residence
Name: Sanjay S. Limaye
Affiliation: University of Wisconsin, Madison
Proposal Title: Investigation of the Venus weather as a Participating Scientist in
Residence
Name: Kevin McGouldrick
Affiliation: University of Colorado, Boulder
Proposal Title: Combined theoretical and observational multi-disciplinary analysis
of the structure and evolution of the clouds and hazes of Venus
Participating Scientist
Name: Charles H. Acton
Affiliation: Jet Propulsion Laboratory, Pasadena, Calif.
Proposal Title: SPICE for Venus Climate Orbiter
Name: Ralph D. Lorenz
Affiliation: Johns Hopkins University Applied Physics Laboratory, Laurel, Md.
Proposal Title: Combined theoretical and observational multi-disciplinary analysis of the structure and evolution of the clouds and hazes of Venus
Name: Gerald Schubert
Affiliation: University of California, Los Angeles
Proposal Title: Modeling Venus atmospheric dynamics with data from the
Venus Climate Orbiter (Akatsuki)
Name: Eliot F. Young
Affiliation: University of California, Los Angeles
Proposal Title: Identifying cloud properties and altitude: spectral image cubes to
accompany Akatsuki image data
Name: Mark A. Bullock
Affiliation: Southwest Research Institute, San Antonio
Proposal Title: Observational and theoretical constraints on current Venus
volcanism from Akatsuki UV and IR imaging
Akatsuki was launched on May 21, 2010 (Japan Standard Time, JST) and is Japan's first mission to Venus. The spacecraft will arrive at Venus on Dec. 7, 2010, and will follow the Venus westward rotation of the atmosphere, mapping the circulation, evolution and vertical structure of the planet's thick clouds.
The three-dimensional structure of the Venusian atmosphere and its temporal variation will be observed by using the Akatsuki spacecraft's imaging cameras (from the ultraviolet to thermal infrared wavelengths), a high-speed lightning detector and radio occultation techniques that will penetrate the thick Venusian atmosphere. Akatsuki's systematic and continuous observations from a quasi-equatorial orbit will provide a complete dataset of atmospheric dynamics.
Mitsubishi Heavy Industries, Ltd. and JAXA launched Akasutki aboard H-IIA Launch Vehicle No. 17 (H-IIA F17) at 6:58:22 a.m. on May 21, 2010 (JST) from the Tanegashima Space Center. The mission lifespan in Venus orbit is approximately two Earth years.
For more information visit: http://www.nasa.gov/topics/solarsystem/features/venus20101119.html.
Sunspot 1123 Hurls Filament toward Earth
UPDATE: Coronagraph images from the Solar and Heliospheric Observatory (SOHO) and NASA's twin STEREO spacecraft show a faint coronal mass ejection emerging from the blast site and heading off in a direction just south of the sun-Earth line.
The cloud could deliver a glancing blow to Earth's magnetic field sometime on Nov. 14th or 15th. High latitude sky watchers should be alert for auroras on those dates.
EARTH-DIRECTED ERUPTION: Active sunspot 1123 erupted during the early hours of Nov. 12th, producing a C4-class solar flare and apparently hurling a filament of material in the general direction of Earth.
For more information visit : http://www.nasa.gov/topics/solarsystem/sunearthsystem/main/News111210-c4flare.html
Detailed Dark Matter Map Yields Clues to Galaxy Cluster Growth
Astronomers using NASA's Hubble Space Telescope took advantage of a giant cosmic magnifying glass to create one of the sharpest and most detailed maps of dark matter in the universe. Dark matter is an invisible and unknown substance that makes up the bulk of the universe's mass.
The new dark matter observations may yield new insights into the role of dark energy in the universe's early formative years. The result suggests that galaxy clusters may have formed earlier than expected, before the push of dark energy inhibited their growth. A mysterious property of space, dark energy fights against the gravitational pull of dark matter. Dark energy pushes galaxies apart from one another by stretching the space between them, thereby suppressing the formation of giant structures called galaxy clusters. One way astronomers can probe this primeval tug-of-war is through mapping the distribution of dark matter in clusters.
A team led by Dan Coe at NASA's Jet Propulsion Laboratory in Pasadena, Calif., used Hubble's Advanced Camera for Surveys to chart the invisible matter in the massive galaxy cluster Abell 1689, located 2.2 billion light-years away. The cluster's gravity, the majority of which comes from dark matter, acts like a cosmic magnifying glass, bending and amplifying the light from distant galaxies behind it. This effect, called gravitational lensing, produces multiple, warped, and greatly magnified images of those galaxies, like the view in a funhouse mirror. By studying the distorted images, astronomers estimated the amount of dark matter within the cluster. If the cluster's gravity only came from the visible galaxies, the lensing distortions would be much weaker.
Based on their higher-resolution mass map, Coe and his collaborators confirm previous results showing that the core of Abell 1689 is much denser in dark matter than expected for a cluster of its size, based on computer simulations of structure growth. Abell 1689 joins a handful of other well-studied clusters found to have similarly dense cores. The finding is surprising, because the push of dark energy early in the universe's history would have stunted the growth of all galaxy clusters.
"Galaxy clusters, therefore, would had to have started forming billions of years earlier in order to build up to the numbers we see today," Coe explains. "At earlier times, the universe was smaller and more densely packed with dark matter. Abell 1689 appears to have been well fed at birth by the dense matter surrounding it in the early universe. The cluster has carried this bulk with it through its adult life to appear as we observe it today."
Mapping the Invisible
Abell 1689 is among the most powerful gravitational lensing clusters ever observed. Coe's observations, combined with previous studies, yielded 135 multiple images of 42 background galaxies.
"The lensed images are like a big puzzle," Coe says. "Here we have figured out, for the first time, a way to arrange the mass of Abell 1689 such that it lenses all of these background galaxies to their observed positions." Coe used this information to produce a higher-resolution map of the cluster's dark matter distribution than was possible before.
Coe teamed with mathematician Edward Fuselier, who, at the time, was at the United States Military Academy at West Point, to devise a new technique to calculate the new map. "Thanks, in large part, to Eddie's contributions, we have finally `cracked the code' of gravitational lensing. Other methods are based on making a series of guesses as to what the mass map is, and then astronomers find the one that best fits the data. Using our method, we can obtain, directly from the data, a mass map that gives a perfect fit."
Astronomers are planning to study more clusters to confirm the possible influence of dark energy. A major Hubble program that will analyze dark matter in gigantic galaxy clusters is the Cluster Lensing and Supernova survey with Hubble (CLASH). In this survey, the telescope will study 25 clusters for a total of one month over the next three years. The CLASH clusters were selected because of their strong X-ray emission, indicating they contain large quantities of hot gas. This abundance means the clusters are extremely massive. By observing these clusters, astronomers will map the dark matter distributions and look for more conclusive evidence of early cluster formation, and possibly early dark energy.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.
For more information visit : http://www.nasa.gov/mission_pages/hubble/science/dark-matter-map.html
Silica on a Mars Volcano Tells of Wet and Cozy Past
PASADENA, Calif. -- Light-colored mounds of a mineral deposited on a volcanic cone more than three billion years ago may preserve evidence of one of the most recent habitable microenvironments on Mars.
Observations by NASA's Mars Reconnaissance Orbiter enabled researchers to identify the mineral as hydrated silica and to see its volcanic context. The mounds' composition and their location on the flanks of a volcanic cone provide the best evidence yet found on Mars for an intact deposit from a hydrothermal environment -- a steam fumarole, or hot spring. Such environments may have provided habitats for some of Earth's earliest life forms.
"The heat and water required to create this deposit probably made this a habitable zone," said J.R. Skok of Brown University, Providence, R.I., lead author of a paper about these findings published online today by Nature Geoscience. "If life did exist there, this would be a promising type of deposit to entomb evidence of it -- a microbial mortuary."
No studies have yet determined whether Mars has ever supported life. The new results add to accumulating evidence that, at some times and in some places, Mars has had favorable environments for microbial life. This specific place would have been habitable when most of Mars was already dry and cold. Concentrations of hydrated silica have been identified on Mars previously, including a nearly pure patch found by NASA's Mars Exploration Rover Spirit in 2007. However, none of those earlier findings were in such an intact setting as this one, and the setting adds evidence about the origin.
Skok said, "You have spectacular context for this deposit. It's right on the flank of a volcano. The setting remains essentially the same as it was when the silica was deposited."
The small cone rises about 100 meters (100 yards) from the floor of a shallow bowl named Nili Patera. The patera, which is the floor of a volcanic caldera, spans about 50 kilometers (30 miles) in the Syrtis Major volcanic region of equatorial Mars. Before the cone formed, free-flowing lava blanketed nearby plains. The collapse of an underground magma chamber from which lava had emanated created the bowl. Subsequent lava flows, still with a runny texture, coated the floor of Nili Patera. The cone grew from even later flows, apparently after evolution of the underground magma had thickened its texture so that the erupted lava would mound up.
"We can read a series of chapters in this history book and know that the cone grew from the last gasp of a giant volcanic system," said John Mustard, Skok's thesis advisor at Brown and a co-author of the paper. "The cooling and solidification of most of the magma concentrated its silica and water content."
Observations by cameras on the Mars Reconnaissance Orbiter revealed patches of bright deposits near the summit of the cone, fanning down its flank, and on flatter ground in the vicinity. The Brown researchers partnered with Scott Murchie of Johns Hopkins University Applied Physics Laboratory, Laurel, Md., to analyze the bright exposures with the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the orbiter.
Silica can be dissolved, transported and concentrated by hot water or steam. Hydrated silica identified by the spectrometer in uphill locations -- confirmed by stereo imaging -- indicates that hot springs or fumaroles fed by underground heating created these deposits. Silica deposits around hydrothermal vents in Iceland are among the best parallels on Earth.
Murchie said, "The habitable zone would have been within and alongside the conduits carrying the heated water." The volcanic activity that built the cone in Nili Patera appears to have happened more recently than the 3.7-billion-year or greater age of Mars' potentially habitable early wet environments recorded in clay minerals identified from orbit.
NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for NASA. Johns Hopkins University Applied Physics Laboratory provided and operates CRISM, one of six instruments on the orbiter. For more information about the Mars Reconnaissance Orbiter.
For more information visit : http://www.nasa.gov/mission_pages/MRO/news/mro20101031.html
NASA's Aqua Satellite Catches a Plume from One of Russia's Most Active Volcanoes
NASA's Aqua satellite flew over the erupting Shiveluch Volcano in Russia today and captured a visible image of its ash plume. Shiveluch is one of Russia's most active volcano and is currently spewing ash over 6 miles high (10 kilometers) into the atmosphere. That's about 33,000 feet high and just shy of the stratosphere.
Shiveluch is also the northernmost active volcano located in Kamchatka Krai peninsula, eastern Russia. It is one of Kamchatka's largest and most active volcanoes. Shiveluch has been an active volcano since 2001.
When NASA's Aqua satellite flew over the Shiveluch volcano on Oct. 28 at 01:30 UTC or 2:30 p.m. local time Asia/Kamchatka (or Oct. 27 9:30 p.m. EDT) it captured a visible image of the volcano's light brown colored ash plume blowing in a southeasterly direction over the western North Pacific Ocean. NASA's MODIS Rapid Response Team is located at NASA's Goddard Space Flight Center in Greenbelt, Md. and provides real-time imagery of Earth from the MODIS instrument that flies aboard NASA's Aqua and Terra satellites.
For more information visit : http://www.nasa.gov/topics/earth/features/Shiveluch.html
First Science Flight of Antarctic Campaign
IceBridge teams took off today for the first science flight of the Antarctic 2010 campaign. Science teams flew across the Weddell Sea with the primary goal of measuring sea ice freeboard (the height of ice above the water level), which is used to estimate sea ice thickness. The DC-8 took off from Punta Arenas, Chile, at about 9 a.m. local time for the 11-hour flight..
Five Things About NASA's EPOXI Mission
Here are five quick facts about the EPOXI mission, scheduled to fly by comet Hartley 2 on Nov. 4, 2010.
1. High Fives - This is the fifth time humans will see a comet close-up, and the Deep Impact spacecraft flew by Earth for its fifth time on Sunday, June 27, 2010.
2. Eco-friendly Spacecraft: Recycle, Reuse, Record - The EPOXI mission is recycling the Deep Impact spacecraft, whose probe intentionally collided with comet Tempel 1 on July 4, 2005, revealing, for the first time, the inner material of a comet. The spacecraft is now approaching a second comet rendezvous, a close encounter with Hartley 2 on Nov. 4. The spacecraft is reusing the same trio of instruments used during Deep Impact: two telescopes with digital imagers to record the encounter, and an infrared spectrometer.
3. Small, Mighty and Square-Dancing in Space - Although comet Hartley 2 is smaller than Tempel 1, the previous comet visited by Deep Impact, it is much more active. In fact, amateur skywatchers may be able to see Hartley 2 in a dark sky with binoculars or a small telescope. Engineers specifically designed the mighty Deep Impact spacecraft to point a camera at Tempel 1 while its antenna was directed at Earth. This flyby of comet Hartley 2 does not provide the same luxury. It cannot both photograph the comet and talk with mission controllers on Earth. Engineers have instead programmed Deep Impact to dance the do-si-do. The spacecraft will spend the week leading up to closest approach swinging back and forth between imaging the comet and beaming images back to Earth.
4. Storytelling Comets - Comets are an important aspect of studying how the solar system formed and Earth evolved. Comets are leftover building blocks of solar system formation, and are believed to have seeded an early Earth with water and organic compounds. The more we know about these celestial bodies, the more we can learn about Earth and the solar system.
5. What's in a Name? - EPOXI is a hybrid acronym binding two science investigations: the Extrasolar Planet Observation and Characterization (EPOCh) and Deep Impact eXtended Investigation (DIXI). The spacecraft keeps its original name of Deep Impact, while the mission is called EPOXI.
For more information visit : http://www.nasa.gov/mission_pages/epoxi/epoxi20101025.html
Pinwheel of Star Birth
Though the universe is chock full of spiral-shaped galaxies, no two look exactly the same. This face-on spiral galaxy, called NGC 3982, is striking for its rich tapestry of star birth, along with its winding arms. The arms are lined with pink star-forming regions of glowing hydrogen, newborn blue star clusters, and obscuring dust lanes that provide the raw material for future generations of stars. The bright nucleus is home to an older population of stars, which grow ever more densely packed toward the center.
NGC 3982 is located about 68 million light-years away in the constellation Ursa Major. The galaxy spans about 30,000 light-years, one-third of the size of our Milky Way galaxy. This color image is composed of exposures taken by the Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2), the Advanced Camera for Surveys (ACS), and the Wide Field Camera 3 (WFC3). The observations were taken between March 2000 and August 2009. The rich color range comes from the fact that the galaxy was photographed invisible and near-infrared light. Also used was a filter that isolates hydrogen emission that emanates from bright star-forming regions dotting the spiral arms.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C.
For more information visit: http://www.nasa.gov/mission_pages/hubble/science/pinwheel.html
NASA's Terra Satellite Catches Powerful Supertyphoon Megi
On October 18, 2010, Typhoon Megi approached and made landfall in the northeastern Isabela Province of the Philippines. Spanning more than 600 kilometers (370 miles) across, Megi was the 15th tropical storm and 7th typhoon of the season in the western Pacific Ocean. It was the most intense tropical cyclone of the year to date.
News reports indicated at least one death and an unknown number of injuries, as power and communications was cut off to more than 90 percent of Isabela and Cagayan provinces. In addition to the immediate damage, officials were concerned about the long-term damage to the rice crop, a staple of the national diet.
This image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite at 10:35 a.m. Philippine Time (02:35 UTC) on October 18, 2010. Megi was bearing down on Palanan Bay as a “super typhoon” with category 5 strength on the Saffir Simpson scale. As of 8:00 a.m. local time, the storm had sustained winds of 268 kilometers (167 miles) per hour, according to the Joint Typhoon Warning Center.
The storm had grown to “super” typhoon status on October 16, and wind speeds peaked at an estimated 287 kilometers (178 miles) per hour while the storm was still over the Pacific Ocean on October 17. Megi began to downgrade as it moved onshore around 11:30 a.m. on October 18 and then crossed over the Sierra Madre mountain range (average elevation 1,800 meters, or 5,900 feet).
The official international name of the storm is Megi, which means “catfish” in Korean. But the storm is known locally as Juan, as the Philippine Atmospheric, Geophysical and Astronomical Services Administration has its own naming system.
Forecasters were predicting that the storm would continue moving west and north, entering the South China Sea and re-intensifying before a potential landfall in China or Vietnam later this week. China's National Meteorological Centre urged local governments to make preparations for extreme weather.
NASA and Gowalla Launch Partnership With Search for Moon Rocks
NASA and Gowalla are bringing people one small step closer to the universe. Anyone who uses Gowalla, a mobile and web service, now has the opportunity to find and collect four NASA-related virtual items -- a moon rock, a NASA patch, a spacesuit and a space shuttle.
Gowalla's mission is to inspire discovery by connecting people with the places around them. When Gowalla users virtually "check-in" at NASA-related venues via their iPhone, Blackberry, Android, Palm or iPad, they now have a chance to find one of the four items.
Virtual moon rocks can be found when Gowalla users check in to any location where a real one is on display. The United States successfully brought lunar samples back to Earth during the Apollo 11, 12, 14, 15, 16, and 17 missions. NASA provides a number of these moon rocks for display and public viewing at museums, planetariums and scientific expositions around the world.
To help people find the lunar samples, Gowalla and JESS3, a creative agency that specializes in data visualization, created a special edition NASA+Gowalla Map: Search for the Moon Rocks.
Gowalla users can find the virtual NASA patch, spacesuit and space shuttles by checking in to NASA visitor centers, agency-related locations, or one of the more than 400 museums, science centers, planetariums, observatories, parks, nature centers, zoos and aquariums that are part of NASA's Museum Alliance.
The partnership also enables a NASA account on Gowalla and an account for astronaut Mike Massimino, both linked to their respective Twitter accounts, @NASA, and @Astro_Mike. NASA and Massimino also will drop virtual items for users to find and collect throughout the nation.
Anyone with a Gowalla account who collects three of the four items will receive a special pin in their Gowalla Passport. In addition, the first 100 people to collect three items will receive a poster of the map in the mail.
For more information visit: http://www.nasa.gov/connect/gowalla.html
Giant Star Goes Supernova, Smothered by its Own Dust
Astronomers using NASA's Spitzer Space Telescope have discovered that a giant star in a remote galaxy ended its life with a dust-shrouded whimper instead of the more typical bang.
Researchers suspect that this odd event -- the first one of its kind ever viewed by astronomers – was more common early in the universe.
It also hints at what we would see if the brightest star system in our Milky Way galaxy exploded, or went supernova.
The discovery is reported in a paper published online in the Astrophysical Journal. The lead author is Christopher Kochanek, a professor of astronomy at Ohio State University, Columbus.
For more information visit: http://www.nasa.gov/mission_pages/spitzer/news/spitzer20101012.html
Small Asteroid to Pass Within Earth-Moon System Tuesday
A small asteroid will fly past Earth early Tuesday within the Earth-moon system. The asteroid, 2010 TD54, will have its closest approach to Earth’s surface at an altitude of about 45,000 kilometers (27,960 miles) at 6:50 EDT a.m. (3:50 a.m. PDT). At that time, the asteroid will be over southeastern Asia in the vicinity of Singapore. During its flyby, Asteroid 2010 TD54 has zero probability of impacting Earth. A telescope of the NASA-sponsored Catalina Sky Survey north of Tucson, Arizona discovered 2010 TD54 on Oct. 9 at (12:55 a.m. PDT) during routine monitoring of the skies.
2010 TD54 is estimated to be about 5 to 10 meters (16 to 33 feet) wide. Due to its small size, the asteroid would require a telescope of moderate size to be viewed. A five-meter-sized near-Earth asteroid from the undiscovered population of about 30 million would be expected to pass daily within a lunar distance, and one might strike Earth's atmosphere about every 2 years on average. If an asteroid of the size of 2010 TD54 were to enter Earth’s atmosphere, it would be expected to burn up high in the atmosphere and cause no damage to Earth’s surface.
The distance used on the Near Earth Object page is always the calculated distance from the center of Earth. The distance stated for 2010 TD54 is 52,000 kilometers (32,000 miles). To get the distance it will pass from Earth’s surface you need to subtract the distance from the center to the surface (which varies over the planet), or about one Earth radii. That puts the pass distance at about 45,500 kilometers (28,000 miles) above the planet.
NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.
JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.
For more information visit: http://www.nasa.gov/topics/solarsystem/features/asteroid20101011.html
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