Tuesday, July 29, 2014

'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

A Confetti-Like Collection of Stars

A Confetti-Like Collection of Stars:

Taken Under the 'Wing' of the Small Magellanic Cloud
The tip of the "wing" of the Small Magellanic Cloud galaxy is dazzling in this new view from NASA's Great Observatories. The Small Magellanic Cloud, or SMC, is a small galaxy about 200,000 light-years way that orbits our own Milky Way spiral galaxy. Image credit: NASA/CXC/JPL-Caltech/STScI
› Full image and caption

April 03, 2013

It's like a disco wonderland for stars. The tip of the "wing" of the Small Magellanic Cloud galaxy is dazzling in pink and purples in a new view from NASA's Great Observatories. The Small Magellanic Cloud is a small galaxy about 200,000 light-years away from own Milky Way spiral galaxy.


The colors represent wavelengths of light across a broad spectrum. X-rays from NASA's Chandra X-ray Observatory are shown in purple; visible-light from NASA's Hubble Space Telescope is colored red, green and blue; and infrared observations from NASA's Spitzer Space Telescope are also represented in red.


The gem of a spiral galaxy seen in the lower corner is actually behind this nebula. Other distant galaxies located hundreds of millions of light-years or more away can be seen sprinkled around the edge of the image.


The three telescopes highlight different aspects of this lively stellar community. Winds and radiation from massive stars located in the central, disco-ball-like cluster of stars, called NGC 602a, have swept away surrounding material, clearing an opening in the star-forming cloud.


Chandra reveals X-rays that seem to be coming largely from low-mass young stars in the central cluster. These stars were picked out previously by infrared and optical surveys, using Spitzer and Hubble respectively.


A new study based on Chandra observations and published in the Astrophysical Journal suggests that the X-ray properties of these young stars are similar to others in different environments. This, in turn, suggests that other related properties -- including the formation and evolution of disks where planets form -- are also likely to be similar.


The full story from Chandra is online at http://chandra.harvard.edu/photo/2013/ngc602/ .


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-122
Posted by Nelio Inacio at 5:38 AM 0 comments

Used Parachute on Mars Flaps in the Wind

Used Parachute on Mars Flaps in the Wind:

MSL's Parachute Flapping in the Wind
This sequence of seven images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter shows wind-caused changes in the parachute of NASA's Mars Science Laboratory spacecraft as the chute lay on the Martian ground during months after its use in safe landing of the Curiosity rover. Image credit: NASA/JPL-Caltech/Univ. of Arizona
› Full image and caption

April 03, 2013

PASADENA, Calif. - Photos from NASA's Mars Reconnaissance Orbiter show how the parachute that helped NASA's Curiosity rover land on Mars last summer has subsequently changed its shape on the ground.


The images were obtained by the High Resolution Imaging Science Experiment (HiRISE) camera on Mars Reconnaissance Orbiter.


Seven images taken by HiRISE between Aug. 12, 2012, and Jan. 13, 2013, show the used parachute shifting its shape at least twice in response to wind.


The images in the sequence of photos are available online at http://uahirise.org/releases/msl-chute.php and at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA16813 .


Researchers have used HiRISE to study many types of changes on Mars. Its first image of Curiosity's parachute, not included in this series, caught the spacecraft suspended from the chute during descent through the Martian atmosphere.


HiRISE is operated by the University of Arizona, Tucson. The instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colo. The Mars Reconnaissance Orbiter Project and Curiosity are managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington. JPL is a division of the California Institute of Technology in Pasadena.


For more information about the Mars Reconnaissance Orbiter, which has been studying Mars from orbit since 2006, visit http://www.nasa.gov/mro .

Guy Webster 818-354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

guy.webster@jpl.nasa.gov


2013-121
Posted by Nelio Inacio at 5:38 AM 0 comments

NASA Mars Spacecraft Prepare for Close Comet Flyby

NASA Mars Spacecraft Prepare for Close Comet Flyby:

This graphic depicts the orbit of comet C/2013 A1 Siding Spring
This graphic depicts the orbit of comet C/2013 A1 Siding Spring as it swings around the sun in 2014. On Oct. 19, the comet will have a very close pass at Mars. Its nucleus will miss Mars by about 82,000 miles (132,000 kilometers). The comet's trail of dust particles shed by the nucleus might be wide enough to reach Mars or might also miss it. See more information about this comet.

› Full image


July 25, 2014

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

The comet's nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle -- estimated to be about one-fiftieth of an inch (half a millimeter) across -- could cause significant damage to a spacecraft.

NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.

"Three expert teams have modeled this comet for NASA and provided forecasts for its flyby of Mars," explained Rich Zurek, chief scientist for the Mars Exploration Program at NASA's Jet Propulsion Laboratory in Pasadena, California. "The hazard is not an impact of the comet nucleus, but the trail of debris coming from it. Using constraints provided by Earth-based observations, the modeling results indicate that the hazard is not as great as first anticipated. Mars will be right at the edge of the debris cloud, so it might encounter some of the particles -- or it might not."

During the day's events, the smallest distance between Siding Spring's nucleus and Mars will be less than one-tenth the distance of any known previous Earthly comet flyby. The period of greatest risk to orbiting spacecraft will start about 90 minutes later and last about 20 minutes, when Mars will come closest to the center of the widening dust trail from the nucleus.

NASA's Mars Reconnaissance Orbiter (MRO) made one orbit-adjustment maneuver on July 2 as part of the process of repositioning the spacecraft for the Oct. 19 event. An additional maneuver is planned for Aug. 27. The team operating NASA's Mars Odyssey orbiter is planning a similar maneuver on Aug. 5 to put that spacecraft on track to be in the right place at the right time, as well.

NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft is on its way to the Red Planet and will enter orbit on Sept. 21. The MAVEN team is planning to conduct a precautionary maneuver on Oct. 9, prior to the start of the mission's main science phase in early November.

In the days before and after the comet's flyby, NASA will study the comet by taking advantage of how close it comes to Mars. Researchers plan to use several instruments on the Mars orbiters to study the nucleus, the coma surrounding the nucleus, and the tail of Siding Spring, as well as the possible effects on the Martian atmosphere. This particular comet has never before entered the inner solar system, so it will provide a fresh source of clues to our solar system's earliest days.

MAVEN will study gases coming off the comet's nucleus into its coma as it is warmed by the sun. MAVEN also will look for effects the comet flyby may have on the planet's upper atmosphere and observe the comet as it travels through the solar wind.

Odyssey will study thermal and spectral properties of the comet's coma and tail. MRO will monitor Mars' atmosphere for possible temperature increases and cloud formation, as well as changes in electron density at high altitudes. The MRO team also plans to study gases in the comet's coma. Along with other MRO observations, the team anticipates this event will yield detailed views of the comet's nucleus and potentially reveal its rotation rate and surface features.

Mars' atmosphere, though much thinner than Earth's, is thick enough that NASA does not anticipate any hazard to the Opportunity and Curiosity rovers on the planet's surface, even if dust particles from the comet hit the atmosphere and form into meteors. Rover cameras may be used to observe the comet before the flyby, and to monitor the atmosphere for meteors while the comet's dust trail is closest to the planet.

Observations from Earth-based and space telescopes provided data used for modeling to make predictions about Siding Spring's Mars flyby, which were in turn used for planning protective maneuvers. The three modeling teams were headed by researchers at the University of Maryland in College Park, the Planetary Science Institute in Tucson, Arizona, and JPL.

For more information about the Mars flyby of comet Siding Spring, visit:

http://mars.nasa.gov/comets/sidingspring

For more information about NASA's Mars Exploration Program, visit:

http://www.nasa.gov/mars

Dwayne Brown

NASA Headquarters, Washington

202-358-1726

dwayne.c.brown@nasa.gov


Guy Webster

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-6278

guy.webster@jpl.nasa.gov


244-2014
Posted by Nelio Inacio at 5:35 AM 0 comments

Sunday, July 27, 2014

Mapping the Chemistry Needed for Life at Europa

Mapping the Chemistry Needed for Life at Europa:

Europa Global Views in Natural and Enhanced Colors
This color composite view combines violet, green, and infrared images of Jupiter's intriguing moon, Europa, for a view of the moon in natural color (left) and in enhanced color designed to bring out subtle color differences in the surface (right). The bright white and bluish part of Europa's surface is composed mostly of water ice, with very few non-ice materials. In contrast, the brownish mottled regions on the right side of the image may be covered by hydrated salts and an unknown red component. The yellowish mottled terrain on the left side of the image is caused by some other unknown component. Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long. Image credit:
NASA/JPL/University of Arizona

› Full image and caption

April 04, 2013

A new paper led by a NASA researcher shows that hydrogen peroxide is abundant across much of the surface of Jupiter's moon Europa. The authors argue that if the peroxide on the surface of Europa mixes into the ocean below, it could be an important energy supply for simple forms of life, if life were to exist there. The paper was published online recently in the Astrophysical Journal Letters.


"Life as we know it needs liquid water, elements like carbon, nitrogen, phosphorus and sulfur, and it needs some form of chemical or light energy to get the business of life done," said Kevin Hand, the paper's lead author, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Europa has the liquid water and elements, and we think that compounds like peroxide might be an important part of the energy requirement. The availability of oxidants like peroxide on Earth was a critical part of the rise of complex, multicellular life."


The paper, co-authored by Mike Brown of the California Institute of Technology in Pasadena, analyzed data in the near-infrared range of light from Europa, using the Keck II Telescope on Mauna Kea, Hawaii, over four nights in September 2011. The highest concentration of peroxide found was on the side of Europa that always leads in its orbit around Jupiter, with a peroxide abundance of 0.12 percent relative to water. (For perspective, this is roughly 20 times more diluted than the hydrogen peroxide mixture available at drug stores.) The concentration of peroxide in Europa's ice then drops off to nearly zero on the hemisphere of Europa that faces backward in its orbit.


Hydrogen peroxide was first detected on Europa by NASA's Galileo mission, which explored the Jupiter system from 1995 to 2003, but Galileo observations were of a limited region. The new results show that peroxide is widespread across much of the surface of Europa, and the highest concentrations are reached in regions where Europa's ice is nearly pure water with very little sulfur contamination. The peroxide is created by the intense radiation processing of Europa's surface ice that comes from the moon's location within Jupiter's strong magnetic field.


"The Galileo measurements gave us tantalizing hints of what might be happening all over the surface of Europa, and we've now been able to quantify that with our Keck telescope observations," Brown said. "What we still don't know is how the surface and the ocean mix, which would provide a mechanism for any life to use the peroxide."


The scientists think hydrogen peroxide is an important factor for the habitability of the global liquid water ocean under Europa's icy crust because hydrogen peroxide decays to oxygen when mixed into liquid water. "At Europa, abundant compounds like peroxide could help to satisfy the chemical energy requirement needed for life within the ocean, if the peroxide is mixed into the ocean," said Hand.


The study was funded 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 Institute 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


2013-126
Posted by Nelio Inacio at 6:05 PM 0 comments
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Gravity-Bending Find Leads to Kepler Meeting Einstein

Gravity-Bending Find Leads to Kepler Meeting Einstein:

This artist's concept depicts a dense, dead star called a white dwarf
This artist's concept depicts a dense, dead star called a white dwarf crossing in front of a small, red star. The white dwarf's gravity is so great it bends and magnifies light from the red star. Image credit: NASA/JPL-Caltech
› Full image and caption

April 04, 2013

NASA's Kepler space telescope has witnessed the effects of a dead star bending the light of its companion star. The findings are among the first detections of this phenomenon -- a result of Einstein's theory of general relativity -- in binary, or double, star systems.


The dead star, called a white dwarf, is the burnt-out core of what used to be a star like our sun. It is locked in an orbiting dance with its partner, a small "red dwarf" star. While the tiny white dwarf is physically smaller than the red dwarf, it is more massive.


"This white dwarf is about the size of Earth but has the mass of the sun," said Phil Muirhead of the California Institute of Technology, Pasadena, lead author of the findings to be published April 20 in the Astrophysical Journal. "It's so hefty that the red dwarf, though larger in physical size, is circling around the white dwarf."


Kepler's primary job is to scan stars in search of orbiting planets. As the planets pass by, they block the starlight by miniscule amounts, which Kepler's sensitive detectors can see.


"The technique is equivalent to spotting a flea on a light bulb 3,000 miles away, roughly the distance from Los Angeles to New York City," said Avi Shporer, co-author of the study, also of Caltech.


Muirhead and his colleagues regularly use public Kepler data to search for and confirm planets around smaller stars, the red dwarfs, also known as M dwarfs. These stars are cooler and redder than our yellow sun. When the team first looked at the Kepler data for a target called KOI-256, they thought they were looking at a huge gas giant planet eclipsing the red dwarf.


"We saw what appeared to be huge dips in the light from the star, and suspected it was from a giant planet, roughly the size of Jupiter, passing in front," said Muirhead.


To learn more about the star system, Muirhead and his colleagues turned to the Hale Telescope at Palomar Observatory near San Diego. Using a technique called radial velocity, they discovered that the red dwarf was wobbling around like a spinning top. The wobble was far too big to be caused by the tug of a planet. That is when they knew they were looking at a massive white dwarf passing behind the red dwarf, rather than a gas giant passing in front.


The team also incorporated ultraviolet measurements of KOI-256 taken by the Galaxy Evolution Explorer (GALEX), a NASA space telescope now operated by the California Institute of Technology in Pasadena. The GALEX observations, led by Cornell University, Ithaca, N.Y., are part of an ongoing program to measure ultraviolet activity in all the stars in Kepler field of view, an indicator of potential habitability for planets in the systems. These data revealed the red dwarf is very active, consistent with being "spun-up" by the orbit of the more massive white dwarf.


The astronomers then went back to the Kepler data and were surprised by what they saw. When the white dwarf passed in front of its star, its gravity caused the starlight to bend and brighten by measurable effects.


"Only Kepler could detect this tiny, tiny effect," said Doug Hudgins, the Kepler program scientist at NASA Headquarters, Washington. "But with this detection, we are witnessing Einstein's theory of general relativity at play in a far-flung star system."


One of the consequences of Einstein's theory of general relativity is that gravity bends light. Astronomers regularly observe this phenomenon, often called gravitational lensing, in our galaxy and beyond. For example, the light from a distant galaxy can be bent and magnified by matter in front of it. This reveals new information about dark matter and dark energy, two mysterious ingredients in our universe.


Gravitational lensing has also been used to discover new planets and hunt for free-floating planets.


In the new Kepler study, scientists used the gravitational lensing to determine the mass of the white dwarf. By combining this information with all the data they acquired, the scientists were also able to measure accurately the mass of the red dwarf and the physical sizes of both stars. Kepler's data and Einstein's theory of relativity have together led to a better understanding of how binary stars evolve.


Other authors include Andrew Vanderburg of the University of California, Berkeley; Avi Shporer, Juliette Becker, Jonathan J. Swift, Sasha Hinkley, J. Sebastian Pineda, Michael Bottom, Christoph Baranec, Reed Riddle, Shriharsh P. Tendulkar, Khanh Bui, Richard Dekany and John Asher Johnson of Caltech; James P. Lloyd and Jim Fuller of Cornell University; Ming Zhao of The Pennsylvania State University, University Park; Andrew W. Howard of University of Hawaii, Hilo; Kaspar von Braun of the Max Planck Institute for Astronomy, Germany; Tabetha S. Boyajian of Yale University, New Haven, Conn.; Nicholas Law of the University of Toronto, Canada; A. N. Ramaprakash, Mahesh Burse, Pravin Chordia, Hillol Das and Sujit Punnadi of the Inter-University Centre for Astronomy & Astrophysics, India.


NASA Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with JPL at the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters. JPL is a division of Caltech.
For more information about the Kepler mission, visit: http://www.nasa.gov/kepler .
Posted by Nelio Inacio at 6:04 PM 0 comments
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Blame it on the Rain (from Saturn's Rings)

Blame it on the Rain (from Saturn's Rings):

Saturn's Ring 'Rain'
This artist's concept illustrates how charged water particles flow into the Saturnian atmosphere from the planet's rings, causing a reduction in atmospheric brightness. The observations were made with the W.M. Keck Observatory on Mauna Kea, Hawaii, with NASA funding. The analysis was led by the University of Leicester, England.
Image credit: NASA/JPL-Caltech/Space Science Institute/University of Leicester
› Larger image

April 10, 2013

A new study tracks the "rain" of charged water particles into the atmosphere of Saturn and finds there is more of it and it falls across larger areas of the planet than previously thought. The study, whose observations were funded by NASA and whose analysis was led by the University of Leicester, England, reveals that the rain influences the composition and temperature structure of parts of Saturn's upper atmosphere. The paper appears in this week's issue of the journal Nature.


"Saturn is the first planet to show significant interaction between its atmosphere and ring system," said James O'Donoghue, the paper's lead author and a postgraduate researcher at Leicester. "The main effect of ring rain is that it acts to 'quench' the ionosphere of Saturn. In other words, this rain severely reduces the electron densities in regions in which it falls."


O'Donoghue explains that the ring's effect on electron densities is important because it explains why, for many decades, observations have shown those densities to be unusually low at certain latitudes on Saturn. The study also helps scientists better understand the origin and evolution of Saturn's ring system and changes in the planet's atmosphere.


"It turns out that a major driver of Saturn's ionospheric environment and climate across vast reaches of the planet are ring particles located some 36,000 miles [60,000 kilometers] overhead," said Kevin Baines, a co-author on the paper, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The ring particles affect both what species of particles are in this part of the atmosphere and where it is warm or cool."


In the early 1980s, images from NASA's Voyager spacecraft showed two to three dark bands on Saturn, and scientists theorized that water could have been showering down into those bands from the rings. Those bands were not seen again until this team observed the planet in near-infrared wavelengths with the W.M Keck Observatory on Mauna Kea, in Hawaii, in April 2011. The effect was difficult to discern because it involves looking for a subtle emission from bright parts of Saturn. It required an instrument like that on Keck, which can split up a large range of light.


The ring rain's effect occurs in Saturn's ionosphere, where charged particles are produced when the otherwise neutral atmosphere is exposed to a flow of energetic particles or solar radiation. When the scientists tracked the pattern of emissions of a particular hydrogen ion with three protons (triatomic hydrogen), they expected to see a uniform planet-wide infrared glow. What they observed instead was a series of light and dark bands - with areas of reduced emission corresponding to water-dense portions of Saturn's rings and areas of high emission corresponding to gaps in the rings.


They surmised that charged water particles from the planet's rings were being drawn towards the planet along Saturn's magnetic field lines and were neutralizing the glowing triatomic hydrogen ions. This leaves large "shadows" in what would otherwise be a planet-wide infrared glow. These shadows cover some 30 to 43 percent of the planet's upper atmosphere surface from around 25 to 55 degrees latitude. This is a significantly larger area than suggested by images from NASA's Voyager mission.


Both Earth and Jupiter have an equatorial region that glows very uniformly. Scientists expected this pattern at Saturn, too, but they instead saw dramatic differences at different latitudes.


"Where Jupiter is glowing evenly across its equatorial regions, Saturn has dark bands where the water is falling in, darkening the ionosphere," said Tom Stallard, a paper co-author at Leicester. "We're now also trying to investigate these features with an instrument on NASA's Cassini spacecraft. If we're successful, Cassini may allow us to view in more detail the way that water is removing ionized particles, such as any changes in the altitude or effects that come with the time of day."


Keck observing time was funded by NASA, with a letter of support from the Cassini mission to Saturn. 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. JPL is a division of the California Institute of Technology in Pasadena, Calif.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Ather Mirza 011-44-116 252 3335

University of Leicester Press Office, England

am74@le.ac.uk


2013-130
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Ice Cloud Heralds Fall at Titan's South Pole

Ice Cloud Heralds Fall at Titan's South Pole:

Polar Vortex in Color
The recently formed south polar vortex stands out in the color-swaddled atmosphere of Saturn's largest moon, Titan, in this natural color view from NASA's Cassini spacecraft. Image credit:
NASA/JPL-Caltech/Space Science Institute
› Full image and caption

April 11, 2013

An ice cloud taking shape over Titan's south pole is the latest sign that the change of seasons is setting off a cascade of radical changes in the atmosphere of Saturn's largest moon. Made from an unknown ice, this type of cloud has long hung over Titan's north pole, where it is now fading, according to observations made by the composite infrared spectrometer (CIRS) on NASA's Cassini spacecraft.


"We associate this particular kind of ice cloud with winter weather on Titan, and this is the first time we have detected it anywhere but the north pole," said the study's lead author, Donald E. Jennings, a CIRS Co-Investigator at NASA's Goddard Space Flight Center in Greenbelt, Md.


The southern ice cloud, which shows up in the far infrared part of the light spectrum, is evidence that an important pattern of global air circulation on Titan has reversed direction. When Cassini first observed the circulation pattern, warm air from the southern hemisphere was rising high in the atmosphere and was transported to the cold north pole. There, the air cooled and sank down to lower layers of the atmosphere and formed ice clouds. A similar pattern, called a Hadley cell, carries warm, moist air from Earth's tropics to the cooler middle latitudes.


Based on modeling, scientists had long predicted a reversal of this circulation once Titan's north pole began to warm and its south pole began to cool. The official transition from winter to spring at Titan's north pole occurred in August 2009. But because each of the moon's seasons lasts about seven-and-a-half Earth years, researchers still did not know exactly when this reversal would happen or how long it would take.


The first signs of the reversal came in data acquired in early 2012, which came shortly after the start of southern fall on Titan, when Cassini images and visual and infrared mapping spectrometer data revealed the presence of a high-altitude "haze hood" and a swirling polar vortex at the south pole. Both features have long been associated with the cold north pole. Later, Cassini scientists reported that infrared observations of Titan's winds and temperatures made by CIRS had provided definitive evidence of air sinking, rather than upwelling, at the south pole. By looking back through the data, the team narrowed down the change in circulation to within six months of the 2009 equinox.


Despite the new activity at the south pole, the southern ice cloud had not appeared yet. CIRS didn't detect it until about July 2012, a few months after the haze and vortex were spotted in the south, according to the study published in Astrophysical Journal Letters in December 2012.


"This lag makes sense because first the new circulation pattern has to bring loads and loads of gases to the south pole. Then, the air has to sink. The ices have to condense. And the pole has to be under enough shadow to protect the vapors that condense to form those ices," said Carrie Anderson, a CIRS team member and Cassini participating scientist at Goddard.


At first blush, the southern ice cloud seems to be building rapidly. The northern ice cloud, on the other hand, was present when Cassini first arrived and has been slowly fading the entire time the spacecraft has been observing it.


So far, the identity of the ice in these clouds has eluded scientists, though they have ruled out simple chemicals, such as methane, ethane and hydrogen cyanide, which are typically associated with Titan. One possibility is that "species X," as some team members call the ice, could be a mixture of organic compounds.


"What's happening at Titan's poles has some analogy to Earth and to our ozone holes," said the CIRS Principal Investigator, Goddard's F. Michael Flasar. "And on Earth, the ices in the high polar clouds aren't just window dressing: They play a role in releasing the chlorine that destroys ozone. How this affects Titan chemistry is still unknown. So it's important to learn as much as we can about this phenomenon, wherever we find it."


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. The mission is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate, Washington. The CIRS team is based at NASA's Goddard Space Flight Center in Greenbelt, Md., where the instrument was built. JPL is a division of the California Institute of Technology.

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


2013-133
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