Tuesday, July 29, 2014

Cassini Spies Bright Venus From Saturn Orbit

Cassini Spies Bright Venus From Saturn Orbit:

Earth's Twin Seen From Saturn
Peering over the shoulder of giant Saturn, through its rings, and across interplanetary space, NASA's Cassini spacecraft spies the bright, cloudy terrestrial planet, Venus. The vast distance from Saturn means that Venus only shows up as a white dot, just above and to the right of the image center. Image credit: NASA/JPL-Caltech/Space Science Institute
› Full image and caption

March 01, 2013

PASADENA, Calif. - A distant world gleaming in sunlight, Earth's twin planet, Venus, shines like a bright beacon in images taken by NASA's Cassini spacecraft in orbit around Saturn.


One special image of Venus and Saturn was taken last November when Cassini was placed in the shadow of Saturn. This allowed Cassini to look in the direction of the sun and Venus, and take a backlit image of Saturn and its rings in a particular viewing geometry called "high solar phase." This observing position reveals details about the rings and Saturn's atmosphere that cannot be seen in lower solar phase.


One of the Venus and Saturn images being released today is a combination of separate red, green and blue images covering the planet and main rings and processed to produce true color. Last December, a false-color version of the mosaic was released.


Another image, taken in January, captures Venus just beyond the limb of Saturn and in close proximity to Saturn's G ring, a thin ring just beyond the main Saturnian rings. The diffuse E ring, which is outside the G ring and created by the spray of the moon Enceladus, also is visible.


These images can be found at http://www.nasa.gov/mission_pages/cassini/multimedia/pia14935.html and http://www.nasa.gov/mission_pages/cassini/multimedia/pia14936.html.


Venus is, along with Mercury, Earth and Mars, one of the rocky "terrestrial" planets in the solar system that orbit relatively close to the sun. Though Venus has an atmosphere of carbon dioxide that reaches nearly 900 degrees Fahrenheit (500 degrees Celsius) and a surface pressure 100 times that of Earth's, it is considered a twin to our planet because of their similar sizes, masses, rocky compositions and close orbits. It is covered in thick sulfuric acid clouds, making it very bright.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team consists of scientists from the U.S., England, France and Germany. The imaging operations center is based at the Space Science Institute in Boulder, Colo.


For more information, visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Steve Mullins 720-974-5859

Space Science Institute, Boulder, Colo.

media@ciclops.org


2013-079
Posted by Nelio Inacio at 5:52 AM 0 comments

Comet to Make Close Flyby of Red Planet in October 2014

Comet to Make Close Flyby of Red Planet in October 2014:

This computer graphic depicts the orbit of comet 2013 A1 (Siding Spring) through the inner solar system.
This computer graphic depicts the orbit of comet 2013 A1 (Siding Spring) through the inner solar system.
Image credit: NASA/JPL-Caltech
› Larger image

March 05, 2013

Comet 2013 A1 (Siding Spring) will make a very close approach to Mars in October 2014.


The latest trajectory of comet 2013 A1 (Siding Spring) generated by the Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., indicates the comet will pass within 186,000 miles (300,000 kilometers) of Mars and there is a strong possibility that it might pass much closer. The NEO Program Office's current estimate based on observations through March 1, 2013, has it passing about 31,000 miles (50,000 kilometers) from the Red Planet's surface. That distance is about two-and-a-half times that of the orbit of outermost moon, Deimos.


Scientists generated the trajectory for comet Siding Spring based on the data obtained by observations since October 2012. Further refinement to its orbit is expected as more observational data is obtained. At present, Mars lies within the range of possible paths for the comet and the possibility of an impact cannot be excluded. However, since the impact probability is currently less than one in 600, future observations are expected to provide data that will completely rule out a Mars impact.


During the close Mars approach the comet will likely achieve a total visual magnitude of zero or brighter, as seen from Mars-based assets. From Earth, the comet is not expected to reach naked eye brightness, but it may become bright enough (about magnitude 8) that it could be viewed from the southern hemisphere in mid-September 2014, using binoculars, or small telescopes.


Scientists at the Near-Earth Object Program Office estimate that comet Siding Spring has been on a more than a million-year journey, arriving from our solar system's distant Oort cloud. The comet could be complete with the volatile gases that short period comets often lack due to their frequent returns to the sun's neighborhood.


Rob McNaught discovered comet 2013 A1 Siding Spring on Jan. 3, 2013, at Siding Spring Observatory in Australia. A study of germane archival observations has unearthed more images of the comet, extending the observation interval back to Oct. 4, 2012.


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.


More information about asteroids and near-Earth objects is at: http://www.jpl.nasa.gov/asteroidwatch . More information about asteroid radar research is at: http://echo.jpl.nasa.gov/ . More information about the Deep Space Network is at: http://deepspace.jpl.nasa.gov/dsn .

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-081
Posted by Nelio Inacio at 5:51 AM 0 comments

A Window into Europa's Ocean Right at the Surface

A Window into Europa's Ocean Right at the Surface:

Taste of the Ocean on Europa's Surface
Based on new evidence from Jupiter's moon Europa, astronomers hypothesize that chloride salts bubble up from the icy moon's global liquid ocean and reach the frozen surface where they are bombarded with sulfur from volcanoes on Jupiter's innermost large moon Io. Image credit: NASA/JPL-Caltech
› Full image and caption

March 05, 2013

If you could lick the surface of Jupiter's icy moon Europa, you would actually be sampling a bit of the ocean beneath. A new paper by Mike Brown, an astronomer at the California Institute of Technology in Pasadena, Calif., and Kevin Hand from NASA's Jet Propulsion Laboratory, also in Pasadena, details the strongest evidence yet that salty water from the vast liquid ocean beneath Europa's frozen exterior actually makes its way to the surface.


The finding, based on some of the best data of its kind since NASA's Galileo mission (1989 to 2003) to study Jupiter and its moons, suggests there is a chemical exchange between the ocean and surface, making the ocean a richer chemical environment. The work is described in a paper that has been accepted for publication in the Astronomical Journal.


The exchange between the ocean and the surface, Brown said, "means that energy might be going into the ocean, which is important in terms of the possibilities for life there. It also means that if you'd like to know what's in the ocean, you can just go to the surface and scrape some off."


Europa's ocean is thought to cover the moon's whole globe and is about 60 miles (100 kilometers) thick under a thin ice shell. Since the days of NASA's Voyager and Galileo missions, scientists have debated the composition of Europa's surface. The infrared spectrometer aboard Galileo was not capable of providing the detail needed to identify definitively some of the materials present on the surface. Now, using the Keck II Telescope on Mauna Kea, Hawaii, and its OSIRIS spectrometer, Brown and Hand have identified a spectroscopic feature on Europa's surface that indicates the presence of a magnesium sulfate salt, a mineral called epsomite, that could have formed by oxidation of a mineral likely originating from the ocean below.


Brown and Hand started by mapping the distribution of pure water ice versus anything else. The spectra showed that even Europa's leading hemisphere contains significant amounts of non-water ice. Then, at low latitudes on the trailing hemisphere-the area with the greatest concentration of the non-water ice material-they found a tiny, never-before-detected dip in the spectrum.


The two researchers tested everything from sodium chloride to Drano in Hand's lab at JPL, where he tries to simulate the environments found on various icy worlds. At the end of the day, the signature of magnesium sulfate persisted.


The magnesium sulfate appears to be generated by the irradiation of sulfur ejected from the Jovian moon Io and, the authors deduce, magnesium chloride salt originating from Europa's ocean. Chlorides such as sodium and potassium chlorides, which are expected to be on the Europa surface, are in general not detectable because they have no clear infrared spectral features. But magnesium sulfate is detectable. The authors believe the composition of Europa's ocean may closely resemble the salty ocean of Earth.


Europa is considered a premier target in the search for life beyond Earth, Hand said. A NASA-funded study team led by JPL and the Johns Hopkins University Applied Physics Laboratory, Laurel, Md., has been working with the scientific community to identify options to explore Europa further. "If we've learned anything about life on Earth, it's that where there's liquid water, there's generally life," Hand said. "And of course our ocean is a nice, salty ocean. Perhaps Europa's salty ocean is also a wonderful place for life."


The work was supported, in part, by the NASA Astrobiology Institute through the Icy Worlds team based at JPL, a division of Caltech. The NASA Astrobiology Institute, based at NASA's Ames Research Center, Moffett Field, Calif., is a partnership among NASA, 15 U.S. teams, and 13 international consortia. The NAI is part of NASA's Astrobiology program, which supports research into the origin, evolution, distribution and future of life on Earth and the potential for life elsewhere.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Brian Bell 626-395-5832

California Institute of Technology

bbell2@caltech.edu


2009-082
Posted by Nelio Inacio at 5:50 AM 0 comments

Comet PANSTARRS Rises to the Occasion Mid-March

Comet PANSTARRS Rises to the Occasion Mid-March:

For those in search of comet L4 PANSTARRS, look to the west after sunset in early and mid-March.
For those in search of comet L4 PANSTARRS, look to the west after sunset in early and mid-March. This graphic shows the comet's expected positions in the sky. Image credit: NASA
› Larger image

March 07, 2013

Comets visible to the naked eye are a rare delicacy in the celestial smorgasbord of objects in the nighttime sky. Scientists estimate that the opportunity to see one of these icy dirtballs advertising their cosmic presence so brilliantly they can be seen without the aid of a telescope or binoculars happens only once every five to 10 years. That said, there may be two naked-eye comets available for your viewing pleasure this year.


"You might have heard of a comet ISON, which may become a spectacular naked-eye comet later this fall," said Amy Mainzer, the principal investigator of NASA's NEOWISE mission at the Jet Propulsion Laboratory in Pasadena, Calif., and self-described cosmic icy dirtball fan. "But if you have the right conditions you don't have to wait for ISON. Within a few days, comet PANSTARRS will be making its appearance in the skies of the Northern Hemisphere just after twilight."


Discovered in June 2011, comet 2011 L4 (PANSTARRS) bears the name of the telescopic survey that discovered it -- the less than mellifluous sounding "Panoramic Survey Telescope and Rapid Response System" which sits atop the Haleakala volcano in Hawaii.


Since its discovery a year-and-a-half ago, observing comet PANSTARRS has been the exclusive dominion of comet aficionados in the Southern Hemisphere, but that is about to change. As the comet continues its well-understood and safe passage through the inner-solar system, its celestial splendor will be lost to those in the Southern Hemisphere, but found by those up north.


"There is a catch to viewing comet PANSTARRS," said Mainzer. "This one is not that bright and is going to be low on the western horizon, so you'll need a relatively unobstructed view to the southwest at twilight and, of course, some good comet-watching weather."


Well, there is one more issue -- the time of day, or night, to view it.


"Look too early and the sky will be too bright," said Rachel Stevenson, a NASA Postdoctoral Fellow at JPL. "Look too late, the comet will be too low and obstructed by the horizon. This comet has a relatively small window."


By March 8, comet PANSTARRS may be viewable for those with a totally unobstructed view of the western horizon for about 15 minutes after twilight. On March 10, it will make its closest approach to the sun about 28 million miles (45 million kilometers) away. As it continues its nightly trek across the sky, the comet may get lost in the sun's glare but should return and be visible to the naked eye by March 12. As time marches on in the month of March, the comet will begin to fade away slowly, becoming difficult to view (even with binoculars or small telescopes) by month's end. The comet will appear as a bright point of light with its diffuse tail pointing nearly straight up from the horizon like an exclamation point.


What, if any, attraction does seeing a relatively dim naked-eye comet with the naked eye hold for someone who works with them every day, with file after file of high-resolution imagery spilling out on her computer workstation?


"You bet I'm going to go look at it!" said Mainzer. "Comet PanSTARRS may be a little bit of a challenge to find without a pair of binoculars, but there is something intimately satisfying to see it with your own two eyes. If you have a good viewing spot and good weather, it will be like the Sword of Gryffindor, it should present itself to anyone who is worthy."


NASA detects, tracks and characterizes asteroids and comets passing relatively 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 predicts their paths 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, DC. JPL is a division of the California Institute of Technology in Pasadena.


More information about asteroids and near-Earth objects is at: http://www.jpl.nasa.gov/asteroidwatch , and on Twitter: @asteroidwatch .

DC Agle (818) 393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


2013-088
Posted by Nelio Inacio at 5:49 AM 0 comments

NASA Helps See Buried Mars Flood Channels in 3-D

NASA Helps See Buried Mars Flood Channels in 3-D:

Visualization of Buried Marte Vallis Channels
This illustration schematically shows where the Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter detected flood channels that had been buried by lava flows in the Elysium Planitia region of Mars.
› Full image and caption

March 07, 2013

PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has provided images allowing scientists for the first time to create a 3-D reconstruction of ancient water channels below the Martian surface.


The spacecraft took numerous images during the past few years that showed channels attributed to catastrophic flooding in the last 500 million years. During this period, Mars had been otherwise considered cold and dry. These channels are essential to understanding the extent to which recent hydrologic activity prevailed during such arid conditions. They also help scientists determine whether the floods could have induced episodes of climate change.


The estimated size of the flooding appears to be comparable to the ancient mega-flood that created the Channeled Scablands in the Pacific Northwest region of the United States, in eastern Washington.


The findings are reported in the March 7 issue of Science Express by a team of scientists from NASA, the Smithsonian Institution in Washington, and the Southwest Research Institute in Builder, Colo.


"Our findings show the scale of erosion that created the channels previously was underestimated and the channel depth was at least twice that of previous approximations," said Gareth Morgan, a geologist at the National Air and Space Museum's Center for Earth and Planetary Studies in Washington and lead author on the paper. "This work demonstrates the importance of orbital sounding radar in understanding how water has shaped the surface of Mars."


The channels lie in Elysium Planitia, an expanse of plains along the Martian equator and the youngest volcanic region on the planet. Extensive volcanism throughout the last several hundred million years covered most of the surface of Elysium Planitia, and this buried evidence of Mars' older geologic history, including the source and most of the length of the 620-mile-long (1000-kilometer-long) Marte Vallis channel system. To probe the length, width and depth of these underground channels, the researchers used the Mars Reconnaissance Orbiter's Shallow Radar (SHARAD).


Marte Vallis' morphology is similar to more ancient channel systems on Mars, especially those of the Chryse basin. Many scientists think the Chryse channels likely were formed by the catastrophic release of ground water, although others suggest lava can produce many of the same features. In comparison, little is known about Marte Vallis.


With the SHARAD radar, the team was able to map the buried channels in three dimensions with enough detail to see evidence suggesting two different phases of channel formation. One phase etched a series of smaller branching, or "anastomosing," channels that are now on a raised "bench" next to the main channel. These smaller channels flowed around four streamlined islands. A second phase carved the deep, wide channels.


"In this region, the radar picked up multiple 'reflectors,' which are surfaces or boundaries that reflect radio waves, so it was possible to see multiple layers, " said Lynn Carter, the paper's co-author from NASA's Goddard Space Flight Center in Greenbelt, Md. "We have rarely seen that in SHARAD data outside of the polar ice regions of Mars."


The mapping also provided sufficient information to establish the floods that carved the channels originated from a now-buried portion of the Cerberus Fossae fracture system. The water could have accumulated in an underground reservoir and been released by tectonic or volcanic activity.


"While the radar was probing thick layers of dry, solid rock, it provided us with unique information about the recent history of water in a key region of Mars," said co-author Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif.


The Italian Space Agency provided the SHARAD instrument on Mars Reconnaissance Orbiter and Sapienza University of Rome leads its operations. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver built the orbiter and supports its operations.


The 3-D image can be viewed online at: http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA16767.
For more about NASA's Mars Reconnaissance Orbiter mission, visit: http://www.nasa.gov/mro .

Jia-Rui Cook/Guy Webster 818-354-0850/354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov / guy.webster@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


Elizabeth Zubritsky 301-614-5438

Goddard Space Flight Center, Greenbelt, Md.

elizabeth.a.zubritsky@nasa.gov


Isabel Lara 202-633-2374

Smithsonian Air and Space Museum, Washington

larai@si.edu


2013-087
Posted by Nelio Inacio at 5:49 AM 0 comments

Cassini Makes Last Close Flyby of Saturnian Moon Rhea

Cassini Makes Last Close Flyby of Saturnian Moon Rhea:

NASA's Cassini spacecraft will be flying close to Saturn's moon Rhea on Saturday
NASA's Cassini spacecraft will be flying close to Saturn's moon Rhea on Saturday, March 9, the last close encounter of Rhea planned for the rest of Cassini's mission. Image credit: NASA/JPL-Caltech
› Larger image

March 07, 2013

NASA's Cassini spacecraft will be swooping close to Saturn's moon Rhea on Saturday, March 9, the last close flyby of Rhea in Cassini's mission. The primary purpose will be to probe the internal structure of the moon by measuring the gravitational pull of Rhea against the spacecraft's steady radio link to NASA's Deep Space Network here on Earth. The results will help scientists understand whether the moon is homogeneous all the way through or whether it has differentiated into the layers of core, mantle and crust.


In addition, Cassini's imaging cameras will take ultraviolet, infrared and visible-light data from Rhea's surface. The cosmic dust analyzer will try to detect any dusty debris flying off the surface from tiny meteoroid bombardments to further scientists' understanding of the rate at which "foreign" objects are raining into the Saturn system.


Cassini will fly within about 600 miles (1,000 kilometers) of the surface. The time of closest approach is around 10:17 a.m. PST (1:17 p.m. EST). This is Cassini's fourth close flyby of Rhea.


On Feb. 10, 2015, Cassini will pass Rhea at about 29,000 miles (47,000 kilometers), but this is not considered a targeted flyby. Cassini has been in orbit around Saturn since 2004 and is in a second mission extension, known as the Solstice mission.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory manages the mission for NASA's Science Mission Directorate, Washington, D.C. JPL is a division of Caltech. For more information on Cassini, visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


2013-085

Images

Bombarded Rhea

Cassini looks over the heavily cratered surface of Rhea during the spacecraft's flyby of the moon on March 10, 2012. Image credit:
NASA/JPL-Caltech/Space Science Institute
› Full image and caption

enlarge image



Posted by Nelio Inacio at 5:48 AM 0 comments

Closest Star System Found in a Century

Closest Star System Found in a Century:

Two Brown Dwarfs in Our Backyard
WISE J104915.57-531906 is at the center of the larger image, which was
taken by the NASA's Wide-field Infrared Survey Explorer (WISE). This is the closest star system discovered since 1916, and the third closest to our sun. It is 6.5 light-years away.
› Full image and caption

March 11, 2013

NASA's Wide-field Infrared Survey Explorer (WISE) has discovered a pair of stars that has taken over the title for the third-closest star system to the sun. The duo is the closest star system discovered since 1916.


Both stars in the new binary system are "brown dwarfs," which are stars that are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result, they are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the sun.


"The distance to this brown dwarf pair is 6.5 light-years -- so close that Earth's television transmissions from 2006 are now arriving there," said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State University, University Park, Pa., and a researcher in Penn State's Center for Exoplanets and Habitable Worlds.


"It will be an excellent hunting ground for planets because the system is very close to Earth, which makes it a lot easier to see any planets orbiting either of the brown dwarfs."


The results will be published in the Astrophysical Journal Letters.


The star system is named "WISE J104915.57-531906" because it was discovered in an infrared map of the entire sky obtained by WISE. It is only slightly farther away than the second-closest star, Barnard's star, which was discovered 6 light-years from the sun in 1916. The closest star system consists of: Alpha Centauri, found to be a neighbor of the sun in 1839 at 4.4 light-years away, and the fainter Proxima Centauri, discovered in 1917 at 4.2 light-years.


Edward (Ned) Wright, the principal investigator for the WISE satellite at UCLA, said, "One major goal when proposing WISE was to find the closest stars to the sun. WISE J1049-5319 is by far the closest star found to date using the WISE data, and the close-up views of this binary system we can get with big telescopes like Gemini and the future James Webb Space Telescope will tell us a lot about the low-mass stars known as brown dwarfs."


The Gemini South telescope in Chile was also used in this study for follow-up observations.


Read the full news release from Penn state at http://science.psu.edu/news-and-events/2013-news/Luhman3-2013 .


WISE completed its all-sky survey in 2011, after surveying the entire sky twice at infrared wavelengths. The maps have been released to the public, but an ongoing project called "AllWISE" will combine data from both sky scans. AllWISE will provide a systematic search across the sky for the nearby moving stars such as WISE J104915.57-531906, and also uncover fainter objects from the distant universe. Those data will be publicly available in late 2013.


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages, and operated, WISE for NASA's Science Mission Directorate. Edward Wright is the principal investigator and is at UCLA. The mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.


More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-090
Posted by Nelio Inacio at 5:47 AM 0 comments

'Hot Spots' Ride a Merry-Go-Round on Jupiter

'Hot Spots' Ride a Merry-Go-Round on Jupiter:

Peering Deep into Jupiter's Atmosphere
The dark hot spot in this false-color image from NASA's Cassini spacecraft is a window deep into Jupiter's atmosphere. All around it are layers of higher clouds, with colors indicating which layer of the atmosphere the clouds are in. Image credit: NASA/JPL-Caltech/SSI/GSFC
› Full image and caption

March 14, 2013

In the swirling canopy of Jupiter's atmosphere, cloudless patches are so exceptional that the big ones get the special name "hot spots." Exactly how these clearings form and why they're only found near the planet's equator have long been mysteries. Now, using images from NASA's Cassini spacecraft, scientists have found new evidence that hot spots in Jupiter's atmosphere are created by a Rossby wave, a pattern also seen in Earth's atmosphere and oceans. The team found the wave responsible for the hot spots glides up and down through layers of the atmosphere like a carousel horse on a merry-go-round.


"This is the first time anybody has closely tracked the shape of multiple hot spots over a period of time, which is the best way to appreciate the dynamic nature of these features," said the study's lead author, David Choi, a NASA Postdoctoral Fellow working at NASA's Goddard Space Flight Center in Greenbelt, Md. The paper is published online in the April issue of the journal Icarus.


Choi and his colleagues made time-lapse movies from hundreds of observations taken by Cassini during its flyby of Jupiter in late 2000, when the spacecraft made its closest approach to the planet. The movies zoom in on a line of hot spots between one of Jupiter's dark belts and bright white zones, roughly 7 degrees north of the equator. Covering about two months (in Earth time), the study examines the daily and weekly changes in the sizes and shapes of the hot spots, each of which covers more area than North America, on average.


Much of what scientists know about hot spots came from NASA's Galileo mission, which released an atmospheric probe that descended into a hot spot in 1995. This was the first, and so far only, in-situ investigation of Jupiter's atmosphere.


"Galileo's probe data and a handful of orbiter images hinted at the complex winds swirling around and through these hot spots, and raised questions about whether they fundamentally were waves, cyclones or something in between," said Ashwin Vasavada, a paper co-author who is based at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and who was a member of the Cassini imaging team during the Jupiter flyby. "Cassini's fantastic movies now show the entire life cycle and evolution of hot spots in great detail."


Because hot spots are breaks in the clouds, they provide windows into a normally unseen layer of Jupiter's atmosphere, possibly all the way down to the level where water clouds can form. In pictures, hot spots appear shadowy, but because the deeper layers are warmer, hot spots are very bright at the infrared wavelengths where heat is sensed; in fact, this is how they got their name.


One hypothesis is that hot spots occur when big drafts of air sink in the atmosphere and get heated or dried out in the process. But the surprising regularity of hot spots has led some researchers to suspect there is an atmospheric wave involved. Typically, eight to 10 hot spots line up, roughly evenly spaced, with dense white plumes of cloud in between. This pattern could be explained by a wave that pushes cold air down, breaking up any clouds, and then carries warm air up, causing the heavy cloud cover seen in the plumes. Computer modeling has strengthened this line of reasoning.


From the Cassini movies, the researchers mapped the winds in and around each hot spot and plume, and examined interactions with vortices that pass by, in addition to wind gyres, or spiraling vortices, that merge with the hot spots. To separate these motions from the jet stream in which the hot spots reside, the scientists also tracked the movements of small "scooter" clouds, similar to cirrus clouds on Earth. This provided what may be the first direct measurement of the true wind speed of the jet stream, which was clocked at about 300 to 450 mph (500 to 720 kilometers per hour) -- much faster than anyone previously thought. The hot spots amble at the more leisurely pace of about 225 mph (362 kilometers per hour).


By teasing out these individual movements, the researchers saw that the motions of the hot spots fit the pattern of a Rossby wave in the atmosphere. On Earth, Rossby waves play a major role in weather. For example, when a blast of frigid Arctic air suddenly dips down and freezes Florida's crops, a Rossby wave is interacting with the polar jet stream and sending it off its typical course. The wave travels around our planet but periodically wanders north and south as it goes.


The wave responsible for the hot spots also circles the planet west to east, but instead of wandering north and south, it glides up and down in the atmosphere. The researchers estimate this wave may rise and fall 15 to 30 miles (24 to 50 kilometers) in altitude.


The new findings should help researchers understand how well the observations returned by the Galileo probe extend to the rest of Jupiter's atmosphere. "And that is another step in answering more of the questions that still surround hot spots on Jupiter," said Choi.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. The mission is managed by JPL for NASA's Science Mission Directorate, Washington.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Elizabeth Zubritsky 301-614-5438

Goddard Space Flight, Center, Greenbelt, Md.

elizabeth.a.zubritsky@nasa.gov


2013-095
Posted by Nelio Inacio at 5:46 AM 0 comments

Moon, Mars Science Conference Events to be Streamed

Moon, Mars Science Conference Events to be Streamed:

Montage of our solar system.
An artist's concept of a solar-system montage featuring the eight planets, a comet and an asteroid. Image credit: NASA/JPL-Caltech› Larger image

March 15, 2013

NASA's Mars Curiosity and lunar GRAIL missions, managed by the Jet Propulsion Laboratory in Pasadena, Calif., will be among those discussed during the 44th Lunar and Planetary Science Conference in Houston on March 18 to 22.


Science briefings for Curiosity and GRAIL (Gravity Recovery and Interior Laboratory) will be streamed live by JPL on Ustream, as follows:


--Mars Curiosity: Monday, March 18, 10 a.m. PDT (1 p.m. EDT), online at http://www.ustream.tv/nasajpl.


-GRAIL and NASA's Lunar Reconnaissance Orbiter: Tuesday, March 19, 10 a.m. PDT (1 p.m. EDT), online at: http://www.ustream.tv/nasajpl2.


The Lunar Reconnaissance Orbiter is managed by NASA's Goddard Space Flight Center, Greenbelt, Md.


The briefings, along with others from the conference, will also be streamed by the conference organizer, the Lunar and Planetary Institute of Houston, at: http://www.livestream.com/lpsc2013.


The institute is managed by the Universities Space Research Association, a national, nonprofit consortium of universities chartered at NASA's request in 1969 by the National Academy of Sciences.


For news products, a complete agenda and other conference information, visit: http://www.lpi.usra.edu/meetings/lpsc2013/. Follow the conference on Twitter and Facebook using the hashtag #lpsc2013: https://twitter.com/lpimeetings and https://www.facebook.com/LunarandPlanetaryInstitute.


More information about NASA's Curiosity mission is online at: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl. More information about NASA's GRAIL mission to the moon is at: http://www.nasa.gov/grail . Follow JPL on Twitter at http://www.twitter.com/nasajpl and on Facebook at http://www.facebook.com/nasajpl.


For information about NASA and agency programs, visit: http://www.nasa.gov.

Guy Webster/Elena Mejia 818-354-5011

Jet Propulsion Laboratory, Pasadena, Calif.

guy.webster@jpl.nasa.gov / elena.mejia@jpl.nasa.gov

2013-098
Posted by Nelio Inacio at 5:46 AM 0 comments

Herschel Discovers Some of the Youngest Stars Ever Seen

Herschel Discovers Some of the Youngest Stars Ever Seen:

Infant Stars Peek Out from Dusty Cradles
Astronomers have found some of the youngest stars ever seen thanks to the Herschel space observatory, a European Space Agency mission with important NASA contributions. Dense envelopes of gas and dust surround the fledging stars known as protostars, making their detection difficult until now. The discovery gives scientists a window into the earliest and least understood phases of star formation. Image credit: NASA/ESA/ESO/JPL-Caltech/Max-Planck Institute for Astronomy
› Full image and caption

March 19, 2013

PASADENA, Calif. - Astronomers have found some of the youngest stars ever seen, thanks to the Herschel space observatory, a European Space Agency mission with important NASA contributions.


Observations from NASA's Spitzer Space Telescope and the Atacama Pathfinder Experiment (APEX) telescope in Chile, a collaboration involving the Max Planck Institute for Radio Astronomy in Germany, the Onsala Space Observatory in Sweden, and the European Southern Observatory in Germany, contributed to the findings.


Dense envelopes of gas and dust surround the fledging stars known as protostars, making their detection difficult. The 15 newly observed protostars turned up by surprise in a survey of the biggest site of star formation near our solar system, located in the constellation Orion. The discovery gives scientists a peek into one of the earliest and least understood phases of star formation.


"Herschel has revealed the largest ensemble of such young stars in a single star-forming region," said Amelia Stutz, lead author of a paper to be published in The Astrophysical Journal and a postdoctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, Germany. "With these results, we are getting closer to witnessing the moment when a star begins to form."


Stars spring to life from the gravitational collapse of massive clouds of gas and dust. This changeover from stray, cool gas to the ball of super-hot plasma we call a star is relatively quick by cosmic standards, lasting only a few hundred thousand years. Finding protostars in their earliest, most short-lived and dimmest stages poses a challenge.


Astronomers long had investigated the stellar nursery in the Orion Molecular Cloud Complex, a vast collection of star-forming clouds, but had not seen the newly identified protostars until Herschel observed the region.


"Previous studies have missed the densest, youngest and potentially most extreme and cold protostars in Orion," Stutz said. "These sources may be able to help us better understand how the process of star formation proceeds at the very earliest stages, when most of the stellar mass is built up and physical conditions are hardest to observe."


Herschel spied the protostars in far-infrared, or long-wavelength, light, which can shine through the dense clouds around burgeoning stars that block out higher-energy, shorter wavelengths, including the light our eyes see.


The Herschel Photodetector Array Camera and Spectrometer (PACS) instrument collected infrared light at 70 and 160 micrometers in wavelength, comparable to the width of a human hair. Researchers compared these observations to previous scans of the star-forming regions in Orion taken by Spitzer. Extremely young protostars identified in the Herschel views but too cold to be picked up in most of the Spitzer data were further verified with radio wave observations from the APEX ground telescope.


"Our observations provide a first glimpse at protostars that have just begun to 'glow' at far-infrared wavelengths," said paper coauthor Elise Furlan, a postdoctoral research associate at the National Optical Astronomy Observatory in Tucson, Ariz.


Of the 15 newly discovered protostars, 11 possess very red colors, meaning their light output trends toward the low-energy end of the electromagnetic spectrum. This output indicates the stars are still embedded deeply in a gaseous envelope, meaning they are very young. An additional seven protostars previously seen by Spitzer share this characteristic. Together, these 18 budding stars comprise only five percent of the protostars and candidate protostars observed in Orion. That figure implies the very youngest stars spend perhaps 25,000 years in this phase of their development, a mere blink of an eye considering a star like our sun lives for about 10 billion years.


Researchers hope to document chronologically each stage of a star's development rather like a family album, from before birth to early infancy, when planets also take shape.


"With these recent findings, we add an important missing photo to the family album of stellar development," said Glenn Wahlgren, Herschel Program Scientist at NASA Headquarters in Washington. "Herschel has allowed us to study stars in their infancy."


Herschel is a European Space Agency mission, with science instruments provided by a consortia of European institutes with important participation by NASA. NASA's Herschel Project Office is based at the agency's Jet Propulsion Laboratory in Pasadena, Calif. JPL is a division of the California Institute of Technology, Pasadena.


For more about Herschel, visit: http://www.nasa.gov/herschel , http://www.esa.int/SPECIALS/Herschel/index.html and http://www.herschel.caltech.edu .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


J.D. Harrington 202-358-5241

NASA Headquarters, Washington

j.d.harrington@nasa.gov


2013-102
Posted by Nelio Inacio at 5:44 AM 0 comments

NASA News Telecon: Planck Cosmology Findings (Update)

NASA News Telecon: Planck Cosmology Findings (Update):

An artist's concept of the Planck spacecraft. Image credit: NASA/JPL-Caltech
An artist's concept of the Planck spacecraft. Image credit: NASA/JPL-Caltech

› Full image and caption

March 19, 2013

PASADENA, Calif. -- NASA will host a news teleconference at 8 a.m. PDT (11 a.m. EDT), Thursday, March 21, to discuss the first cosmology results from Planck, a European Space Agency mission with significant NASA participation.


Planck launched into space in 2009 and has been scanning the skies ever since, mapping cosmic microwave background, or the afterglow, of the theoretical big bang that created the universe more than 13 billion years ago. NASA contributed mission-enabling technology for both of Planck's science instruments, and U.S., European and Canadian scientists work together to analyze the Planck data.


The teleconference participants are:


-- Paul Hertz, director of astrophysics, NASA Headquarters, Washington
-- Charles Lawrence, U.S. Planck project scientist, NASA's Jet Propulsion Laboratory, Pasadena, Calif.
-- Martin White, U.S. Planck scientist, University of California, Berkeley, Calif.; and Faculty Senior Scientist at Lawrence Berkeley Laboratory
-- Krzysztof Gorski, U.S. Planck scientist, JPL
-- Marc Kamionkowski, professor of physics and astronomy, John Hopkins University, Baltimore, Md.


This event previously was scheduled as a televised news conference.


Questions may be submitted via Twitter using the hashtag #AskNASA .


Visuals will be posted at the start of the teleconference on NASA's Planck website: http://www.nasa.gov/planck .


Audio of the teleconference will be streamed live on NASA's website at:
http://www.nasa.gov/newsaudio . The event will also be streamed live on Ustream at:
http://www.ustream.tv/nasajpl2 .


For additional information about Planck, visit:
http://www.esa.int/planck .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


J.D. Harrington 202-358-5241

NASA Headquarters, Washington

j.d.harrington@nasa.gov


ADVISORY: 2013-105
Posted by Nelio Inacio at 5:43 AM 0 comments

Sun in the Way Will Affect Mars Missions in April

Sun in the Way Will Affect Mars Missions in April:

Artist's concept of NASA's Voyager spacecraft.
Artist's concept of NASA's Voyager spacecraft. Image credit: NASA/JPL-Caltech

March 20, 2013

"The Voyager team is aware of reports today that NASA's Voyager 1 has left the solar system," said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena, Calif. "It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space. In December 2012, the Voyager science team reported that Voyager 1 is within a new region called 'the magnetic highway' where energetic particles changed dramatically. A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space and that change of direction has not yet been observed."


To learn more about the current status of the Voyager mission, visit:
http://www.jpl.nasa.gov/news/news.php?release=2012-381


The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, Calif. Caltech manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov

2013-107
Posted by Nelio Inacio at 5:43 AM 0 comments

Saturn is Like an Antiques Shop, Cassini Suggests

Saturn is Like an Antiques Shop, Cassini Suggests:

Bright Moons
The Cassini spacecraft observes three of Saturn's moons set against the darkened night side of the planet. Image Credit:
NASA/JPL/Space Science Institute
› Full image and caption

March 26, 2013

A new analysis of data from NASA's Cassini spacecraft suggests that Saturn's moons and rings are gently worn vintage goods from around the time of our solar system's birth.


Though they are tinted on the surface from recent "pollution," these bodies date back more than 4 billion years. They are from around the time that the planetary bodies in our neighborhood began to form out of the protoplanetary nebula, the cloud of material still orbiting the sun after its ignition as a star. The paper, led by Gianrico Filacchione, a Cassini participating scientist at Italy's National Institute for Astrophysics, Rome, has just been published online by the Astrophysical Journal.


"Studying the Saturnian system helps us understand the chemical and physical evolution of our entire solar system," said Filacchione. "We know now that understanding this evolution requires not just studying a single moon or ring, but piecing together the relationships intertwining these bodies."


Data from Cassini's visual and infrared mapping spectrometer (VIMS) have revealed how water ice and also colors -- which are the signs of non-water and organic materials --are distributed throughout the Saturnian system. The spectrometer's data in the visible part of the light spectrum show that coloring on the rings and moons generally is only skin-deep.


Using its infrared range, VIMS also detected abundant water ice - too much to have been deposited by comets or other recent means. So the authors deduce that the water ices must have formed around the time of the birth of the solar system, because Saturn orbits the sun beyond the so-called "snow line." Out beyond the snow line, in the outer solar system where Saturn resides, the environment is conducive to preserving water ice, like a deep freezer. Inside the solar system's "snow line," the environment is much closer to the sun's warm glow, and ices and other volatiles dissipate more easily.


The colored patina on the ring particles and moons roughly corresponds to their location in the Saturn system. For Saturn's inner ring particles and moons, water-ice spray from the geyser moon Enceladus has a whitewashing effect.


Farther out, the scientists found that the surfaces of Saturn's moons generally were redder the farther they orbited from Saturn. Phoebe, one of Saturn's outer moons and an object thought to originate in the far-off Kuiper Belt, seems to be shedding reddish dust that eventually rouges the surface of nearby moons, such as Hyperion and Iapetus.


A rain of meteoroids from outside the system appears to have turned some parts of the main ring system - notably the part of the main rings known as the B ring -- a subtle reddish hue. Scientists think the reddish color could be oxidized iron -- rust -- or polycyclic aromatic hydrocarbons, which could be progenitors of more complex organic molecules.


One of the big surprises from this research was the similar reddish coloring of the potato-shaped moon Prometheus and nearby ring particles. Other moons in the area were more whitish.


"The similar reddish tint suggests that Prometheus is constructed from material in Saturn's rings," said co-author Bonnie Buratti, a VIMS team member based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Scientists had been wondering whether ring particles could have stuck together to form moons -- since the dominant theory was that the rings basically came from satellites being broken up. The coloring gives us some solid proof that it can work the other way around, too."


"Observing the rings and moons with Cassini gives us an amazing bird's-eye view of the intricate processes at work in the Saturn system, and perhaps in the evolution of planetary systems as well," said Linda Spilker, Cassini project scientist, based at JPL. "What an object looks like and how it evolves depends a lot on location, location, location."


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, Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson.

Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


2013-117
Posted by Nelio Inacio at 5:41 AM 0 comments

Hunting Massive Stars with Herschel

Hunting Massive Stars with Herschel:

Churning Out Stars
W3 is an enormous stellar nursery about 6,200 light-years away in the Perseus Arm, one of the Milky Way galaxy's main spiral arms, which hosts both low- and high-mass star formation. In this image from the Herschel space observatory, the low-mass forming stars are seen as tiny yellow dots embedded in cool red filaments, while the highest-mass stars -- with greater than eight times the mass of our sun -- emit intense radiation, heating up the gas and dust around them and appearing here in blue. Image credits: ESA/PACS & SPIRE consortia, A. Rivera-Ingraham & P.G. Martin, Univ. Toronto, HOBYS Key Programme (F. Motte)
› Full image and caption

March 28, 2013

In this new view of a vast star-forming cloud called W3, the Herschel space observatory tells the story of how massive stars are born. Herschel is a European Space Agency mission with important NASA contributions.


W3 is a giant gas cloud containing an enormous stellar nursery, some 6,200 light-years away in the Perseus Arm, one of our Milky Way galaxy's main spiral arms.


By studying regions of massive star formation in W3, scientists have made progress in solving one of the major conundrums in the birth of massive stars. That is, even during their formation, the radiation blasting away from these stars is so powerful that they should push away the very material from which they feed. If this is the case, how can massive stars form at all?


Observations of W3 point toward a possible solution: in these very dense regions, there appears to be a continuous process by which the raw material is moved around, compressed and confined, under the influence of clusters of young, massive stars called protostars.


Through their strong radiation and powerful winds, populations of young, high-mass stars may well be able to build and maintain localized clumps of material from which they can continue to feed during their earliest and most chaotic years, despite their incredible energy output.


The W3 star-formation complex is one of the largest in the outer Milky Way, hosting the formation of both low- and high-mass stars. The distinction between low- and high-mass stars is drawn at eight times the mass of our own sun: above this limit, stars end their lives as supernovas.


Dense, bright blue knots of hot dust marking massive star formation dominate the upper left of the image. Intense radiation streaming away from the stellar infants heats up the surrounding dust and gas, making it shine brightly in Herschel's infrared-sensitive eyes.


Older high-mass stars are also seen to be heating up dust in their environments, appearing as the blue regions, for example, lower down and to the left.


Extensive networks of much colder gas and dust weave through the scene in the form of red filaments and pillar-like structures. Several of these cold cores conceal low-mass star formation, hinted at by tiny yellow knots of emission.


Herschel is a European Space Agency mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.


More information is online at http://www.herschel.caltech.edu , http://www.nasa.gov/herschel and http://www.esa.int/SPECIALS/Herschel .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-118
Posted by Nelio Inacio at 5:40 AM 0 comments

NASA Team Investigates Complex Chemistry at Titan

NASA Team Investigates Complex Chemistry at Titan:

Titan Up Front
The colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Image credit:
NASA/JPL-Caltech/Space Science Institute
› Full image and caption

April 02, 2013

A laboratory experiment at NASA's Jet Propulsion Laboratory, Pasadena, Calif., simulating the atmosphere of Saturn's moon Titan suggests complex organic chemistry that could eventually lead to the building blocks of life extends lower in the atmosphere than previously thought. The results now point out another region on the moon that could brew up prebiotic materials. The paper was published in Nature Communications this week.


"Scientists previously thought that as we got closer to the surface of Titan, the moon's atmospheric chemistry was basically inert and dull," said Murthy Gudipati, the paper's lead author at JPL. "Our experiment shows that's not true. The same kind of light that drives biological chemistry on Earth's surface could also drive chemistry on Titan, even though Titan receives far less light from the sun and is much colder. Titan is not a sleeping giant in the lower atmosphere, but at least half awake in its chemical activity."


Scientists have known since NASA's Voyager mission flew by the Saturn system in the early 1980s that Titan, Saturn's largest moon, has a thick, hazy atmosphere with hydrocarbons, including methane and ethane. These simple organic molecules can develop into smog-like, airborne molecules with carbon-nitrogen-hydrogen bonds, which astronomer Carl Sagan called "tholins."


"We've known that Titan's upper atmosphere is hospitable to the formation of complex organic molecules," said co-author Mark Allen, principal investigator of the JPL Titan team that is a part of the NASA Astrobiology Institute, headquartered at Ames Research Center, Moffett Field, Calif. "Now we know that sunlight in the Titan lower atmosphere can kick-start more complex organic chemistry in liquids and solids rather than just in gases."


The team examined an ice form of dicyanoacetylene -- a molecule detected on Titan that is related to a compound that turned brown after being exposed to ambient light in Allen's lab 40 years ago.


In this latest experiment, dicyanoacetylene was exposed to laser light at wavelengths as long as 355 nanometers. Light of that wavelength can filter down to Titan's lower atmosphere at a modest intensity, somewhat like the amount of light that comes through protective glasses when Earthlings view a solar eclipse, Gudipati said. The result was the formation of a brownish haze between the two panes of glass containing the experiment, confirming that organic-ice photochemistry at conditions like Titan's lower atmosphere could produce tholins.


The complex organics could coat the "rocks" of water ice at Titan's surface and they could possibly seep through the crust, to a liquid water layer under Titan's surface. In previous laboratory experiments, tholins like these were exposed to liquid water over time and developed into biologically significant molecules, such as amino acids and the nucleotide bases that form RNA.


"These results suggest that the volume of Titan's atmosphere involved in the production of more complex organic chemicals is much larger than previously believed," said Edward Goolish, acting director of NASA's Astrobiology Institute. "This new information makes Titan an even more interesting environment for astrobiological study."


The team included Isabelle Couturier of the University of Provence, Marseille, France; Ronen Jacovi, a NASA postdoctoral fellow from Israel; and Antti Lignell, a Finnish Academy of Science postdoctoral fellow from Helsinki at JPL.


Founded in 1998, the NASA Astrobiology Institute is a partnership between NASA, 15 U.S. teams and 13 international consortia. It is based at NASA Ames Research Center, Moffett Field, Calif. The Institute's goals are to promote, conduct and lead interdisciplinary astrobiology research, train a new generation of astrobiology researchers, and share the excitement of astrobiology with learners of all ages. The NAI is part of NASA's Astrobiology program, which supports research into the origin, evolution, distribution and future of life on Earth and the potential for life elsewhere. For more information, visit http://astrobiology.nasa.gov/.


JPL is a division of the California Institute of Technology, Pasadena.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


James Schalkwyk 650-604-2791

Ames Research Center, Moffett Field, Calif.

james.schalkwyk@nasa.gov


2013-120
Posted by Nelio Inacio at 5:40 AM 0 comments

NASA Flies Radar South on Wide-Ranging Expedition

NASA Flies Radar South on Wide-Ranging Expedition:

On March 17, 2013, NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR)
On March 17, 2013, NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) acquired synthetic aperture radar data over the Napo River in Ecuador and Peru. The image colors indicate the likelihood of inundation (flooding) beneath the forest canopy, which is difficult to determine using traditional optical sensors. Image credit: NASA/JPL-Caltech
› Full image and caption

April 03, 2013

PASADENA, Calif. - A versatile NASA airborne imaging radar system is showcasing its broad scientific prowess for studying our home planet during a month-long expedition over the Americas.


A NASA C-20A piloted aircraft carrying the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is wrapping up studies over the U.S. Gulf Coast, Arizona, and Central and South America. The plane left NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., on March 7. NASA's Jet Propulsion Laboratory, Pasadena, Calif., built and manages UAVSAR.


The campaign is addressing a broad range of science questions, from the dynamics of Earth's crust and glaciers to the carbon cycle and the lives of ancient Peruvian civilizations. Flights are being conducted over Argentina, Bolivia, Chile, Colombia, Costa Rica, El Salvador, Ecuador, Guatemala, Honduras, Nicaragua and Peru.


UAVSAR uses a technique called interferometry that sends microwave energy pulses from the sensor on the aircraft to the ground. This technique can detect and measure subtle changes in Earth's surface, such as those caused by earthquakes, volcanoes, landslides and glacier movements. The radar's L-band microwaves can penetrate clouds and the tops of forests, making it valuable for studying cloud-covered tropical environments and mapping flooded ecosystems.


"This campaign highlights UAVSAR's versatility for Earth studies," said Naiara Pinto, UAVSAR science coordinator at JPL. "In many cases, study sites are being used by multiple investigators. For example, some volcanic sites also have glaciers. The studies also help U.S. researchers establish and broaden scientific collaborations with Latin America."


Volcano scientists will compare UAVSAR's images taken during this campaign with new imagery collected in 2014 to measure very subtle sub-centimeter changes in Earth's surface associated with the movement of magma deep beneath active volcanoes. These results are expected to improve models used to understand and potentially mitigate volcanic hazards. The volcanoes being studied are in Argentina, Bolivia, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Nicaragua and Peru.


UAVSAR glacier data from South America's Andes Mountains will be combined with ground measurements and airborne lidar data to determine how much these glaciers move during summer and from year to year. The U.S. Geological Survey is leading the collaborative project with the Chilean government to understand glacier processes within the context of climate change impacts from human activities. The glaciers being imaged by UAVSAR provide freshwater for the residents of Santiago and water for regional agriculture.


This year's study sites include coastal mangroves in Central and South America. "Much of Earth's population lives along coasts, and its livelihood and well-being depend on services provided by marine ecosystems," said JPL's Marc Simard, one of the campaign's many principal investigators. "These regions are among the most fragile on Earth. It is critical to understand how the interactions of human activities and climate change may impact the sustainability of these ecosystems."


Another principal investigator, Kyle McDonald, jointly of JPL and the City University of New York Cooperative Remote Sensing Science and Technology Center (CREST) Institute, is leading four data collections that will support the mapping of wetlands across the greater Amazon River basin, including Pacaya-Samiria National Park in Peru. "Pacaya-Samiria contains large expanses of flooded palm swamps," McDonald said. "These ecosystems are potential major sources of atmospheric methane, an important greenhouse gas. UAVSAR will help us better understand processes involved with the exchange of methane between Earth's land and atmosphere, and with the contribution of these unique ecosystems to Earth's climate."


UAVSAR also is supporting agricultural studies of vineyards in Chile's La Serena region. The efforts will help scientists at the Universidad de La Serena's Terra Pacific Group better understand the value of soil moisture data in grape and wine production. Another study site in Argentina will be overflown by both UAVSAR and the Argentine sensor SARAT as part of a collaboration between research scientist Thomas Jackson of the U.S. Department of Agriculture and Argentina's Comision Nacional de Actividades Espaciales. These studies assist scientists preparing for the launch of NASA's Soil Moisture Active Passive (SMAP) satellite in 2014.


The radar also is imaging the northern coastal Peruvian desert, where the Moche culture lived almost 2,000 years ago. Researchers are using UAVSAR's vegetation and cloud penetrating capabilities to search for unrecorded archaeological features in an attempt to preserve sensitive sites from encroaching civilization.


JPL researcher Sassan Saatchi is using UAVSAR to study the structure, biomass and diversity of tropical cloud forests in the Peruvian Andes and Manu National Park, continuing his work there during the past decade. The data will be used to evaluate how much carbon the forests contain and assess their vulnerability to human and natural disturbances.


UAVSAR also is monitoring seasonal land subsidence and uplift in groundwater basins in Arizona's Cochise County for the Arizona Department of Water Resources. Other subsidence studies in New Orleans and the Mississippi Delta are aimed at better understanding what causes Gulf Coast subsidence and predicting future subsidence rates. The data can help agencies better manage the protection of infrastructure, including levees in the New Orleans area.


For more information on UAVSAR, visit: http://uavsar.jpl.nasa.gov . For more on NASA's Airborne Science program, visit: http://airbornescience.nasa.gov .


The California Institute of Technology in Pasadena manages JPL for NASA.

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.buis@jpl.nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

Stephen.e.cole@nasa.gov


2013-123
Posted by Nelio Inacio at 5:39 AM 0 comments
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