Thursday, July 31, 2014

NASA's Cassini Sees Burp at Saturn After Large Storm

NASA's Cassini Sees Burp at Saturn After Large Storm:

These red, orange and green clouds (false color) in Saturn's northern hemisphere indicate the tail end of a massive storm
These red, orange and green clouds (false color) in Saturn's northern hemisphere indicate the tail end of a massive storm that started in December 2010. Even after visible signs of the storm started to fade, infrared measurements continued to reveal powerful effects at work in Saturn's stratosphere. Image credit:NASA/JPL-Caltech/Space Science Institute
› Full image and caption

October 25, 2012

PASADENA, Calif. -- NASA's Cassini spacecraft has tracked the aftermath of a rare massive storm on Saturn. Data reveal record-setting disturbances in the planet's upper atmosphere long after the visible signs of the storm abated, in addition to an indication the storm was more forceful than scientists previously thought.


Data from Cassini's composite infrared spectrometer (CIRS) instrument revealed the storm's powerful discharge sent the temperature in Saturn's stratosphere soaring 150 degrees Fahrenheit (83 kelvins) above normal. At the same time, researchers at NASA's Goddard Spaceflight Center in Greenbelt, Md., detected a huge increase in the amount of ethylene gas, the origin of which is a mystery. Ethylene, an odorless, colorless gas, isn't typically observed on Saturn. On Earth, it is created by natural and man-made sources.


Goddard scientists describe the unprecedented belch of energy in a paper to be published in the Nov. 20 issue of the Astrophysical Journal.


"This temperature spike is so extreme it's almost unbelievable, especially in this part of Saturn's atmosphere, which typically is very stable," said Brigette Hesman, the study's lead author and a University of Maryland scientist who works at Goddard. "To get a temperature change of the same scale on Earth, you'd be going from the depths of winter in Fairbanks, Alaska, to the height of summer in the Mojave Desert."


First detected by Cassini in Saturn's northern hemisphere on Dec. 5, 2010, the storm grew so large that an equivalent storm on Earth would blanket most of North America from north to south and wrap around our planet many times. This type of giant disturbance on Saturn typically occurs every 30 Earth years, or once every Saturn year.


Not only was this the first storm of its kind to be studied by a spacecraft in orbit around the planet, but it was the first to be observed at thermal infrared wavelengths. Infrared data from CIRS allowed scientists to take the temperature of Saturn's atmosphere and to track phenomena that are invisible to the naked eye.


Temperature measurements by the composite infrared spectrometer, first published in May 2011, revealed two unusual beacons of warmer-than-normal air shining brightly in the stratosphere. These indicated a massive release of energy into the atmosphere. After the visible signs of the storm started to fade, the instrument's data revealed the two beacons had merged. The temperature of this combined air mass shot up to more than minus 64 degrees Fahrenheit (above 220 kelvins).


According to Hesman, the huge spike of ethylene generated at the same time peaked with 100 times more of the gas than scientists thought possible for Saturn. Goddard scientists confirmed the release of ethylene using the Celeste spectrometer mounted on the McMath-Pierce Solar Telescope on Kitt Peak in Arizona.


The team still is exploring the origin of the ethylene, but has ruled out a large reservoir deep in the atmosphere.

"We've really never been able to see ethylene on Saturn before, so this was a complete surprise," said Goddard's Michael Flasar, the CIRS team lead.


A complementary paper led by Cassini team associate Leigh Fletcher of Oxford University, England, describes how the two stratospheric beacons merged to become the largest and hottest stratospheric vortex ever detected in our solar system. Initially, it was larger than Jupiter's Great Red Spot.


Their paper in the journal Icarus, which combines CIRS data with additional infrared images from other Earth-based telescopes, including NASA's Infrared Telescope Facility at Mauna Kea, Hawaii, also reports a powerful collar of clockwise winds -- encompassing a bizarre soup of gases -- around the vortex.


"These studies will give us new insight into some of the photochemical processes at work in the stratospheres of Saturn, other giants in our solar system, and beyond," said Scott Edgington, Cassini deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.


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 in Washington. Hesman's work was funded in part by NASA's Planetary Astronomy Program in Washington. The CIRS instrument and Celeste spectrometer were built at Goddard. JPL is managed by the California Institute of Technology, Pasadena.


To read more about the Fletcher paper, visit: http://www.esa.int/esaSC/SEMLPIMFL8H_index_0.html.


For information about Cassini and this observation, 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


Elizabeth Zubritsky/Nancy Neal-Jones 301-614-5438/301-286-0039

Goddard Space Flight, Center, Greenbelt, Md.

elizabeth.a.zubritsky@nasa.gov /nancy.n.jones@nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2012-335
Posted by Nelio Inacio at 12:47 PM 0 comments

Mars Longevity Champ Switching Computers

Mars Longevity Champ Switching Computers:

NASA's Mars Odyssey spacecraft passes above Mars' south pole in this artist's concept.
NASA's Mars Odyssey spacecraft passes above Mars' south pole in this artist's concept. The spacecraft has been orbiting Mars since October 24, 2001. Image credit: NASA/JPL

› Full image and caption


November 01, 2012

PASADENA, Calif. -- NASA's Mars Odyssey orbiter, already the longest-working spacecraft ever sent to Mars, will switch to some fresh, redundant equipment next week that has not been used since before launch in 2001.


Like many spacecraft, this orbiter carries a pair of redundant main computers, so that a backup is available if one fails. Odyssey's "A-side" computer and "B-side" computer each have several other redundant subsystems linked to just that computer. The Odyssey team has decided to switch to the B-side computer to begin using the B-side's inertial measurement unit. This gyroscope-containing mechanism senses changes in the spacecraft's orientation, providing important information for control of pointing the antenna, solar arrays and instruments.


"We have been on the A side for more than 11 years. Everything on the A side still works, but the inertial measurement unit on that side has been showing signs of wearing out," said Odyssey Mission Manager Chris Potts at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We will swap to the B side on Nov. 5 so that we still have some life available in reserve on the A side."


In many potential problem situations, the Odyssey's autonomous fault-protection response would switch the spacecraft from the active side to the other side. By preserving the capability of switching back to a fully functional A side, the mission continues to have the available protection of switching sides temporarily and correcting any fixable anomaly on the B side.


"The spare inertial measurement unit is factory new, last operated on the day before launch," Potts said.


Odyssey launched April 7, 2001, began orbiting Mars on Oct. 24 of that year, began systematic science observations of Mars in early 2002, and broke the previous record for longest-working Mars spacecraft in December 2010.


The side swap on Nov. 5 will intentionally put Odyssey into a reduced-activity status called "safe mode." As the team and the spacecraft verify all systems can operate well over the following several days, the orbiter will return to full operations, conducting its own science observations, as well as serving as a communications relay for NASA's active Mars rovers Opportunity and Curiosity.


The Mars Reconnaissance Orbiter, which shares the data relay return responsibility for the rovers at Mars, will carry the full burden of relay support for both rovers -- Opportunity and Curiosity -- during Odyssey's side-swap period. There will be a reduction in the total amount of relay data returned from Mars. The rover teams will reduce the amount of data planned for downlinking until Odyssey returns to full capacity after the side swap is complete, and will maintain near-normal tactical operations in the interim.


Odyssey's longevity enables continued science, including the monitoring of seasonal changes on Mars from year to year, and continued communication-relay service.


Odyssey is managed by NASA's Jet Propulsion Laboratory, Pasadena, for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft. JPL and Lockheed Martin collaborate on operating the spacecraft. For more about the Mars Odyssey mission, visit: http://mars.jpl.nasa.gov/odyssey .

Guy Webster 818-354-6278

Jet Propulsion Laboratory, Pasadena, Calif.
November 1, 2012
guy.webster@jpl.nasa.gov


2012-347
Posted by Nelio Inacio at 12:46 PM 0 comments

Scientists Monitor Comet Breakup

Scientists Monitor Comet Breakup:

Comet 168P-Hergenrother was imaged by the NOAO/Gemini telescope on Nov. 2, 2011 at about 6 a.m. UTC.
Comet 168P-Hergenrother was imaged by the NOAO/Gemini telescope on Nov. 2, 2011 at about 6 a.m. UTC. Image credit: NASA/JPL-Caltech/NOAO/Gemini

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November 02, 2012

The Hergenrother comet is currently traversing the inner-solar system. Amateur and professional astronomers alike have been following the icy-dirt ball over the past several weeks as it has been generating a series of impressive outbursts of cometary-dust material. Now comes word that the comet's nucleus has taken the next step in its relationship with Mother Nature.


"Comet Hergenrother is splitting apart," said Rachel Stevenson, a post-doctoral fellow working at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Using the National Optical Astronomy Observatory's Gemini North Telescope on top of Mauna Kea, Hawaii, we have resolved that the nucleus of the comet has separated into at least four distinct pieces resulting in a large increase in dust material in its coma."


With more material to reflect the sun's rays, the comet's coma has brightened considerably.


"The comet fragments are considerably fainter than the nucleus," said James Bauer, the deputy principal investigator for NASA's NEOWISE mission, from the California Institute of Technology. "This is suggestive of chunks of material being ejected from the surface."


The comet's fragmentation event was initially detected on Oct. 26 by a team of astronomers from the Remanzacco Observatory, using the Faulkes Telescope North in Haleakala, Hawaii. The initial fragment was also imaged by the WIYN telescope group at Kitt Peak National Observatory in Arizona.


For those interested in viewing Hergenrother, with a larger-sized telescope and a dark sky, the comet can be seen in between the constellations of Andromeda and Lacerta.


The orbit of comet 168P/Hergenrother comet is well understood. The comet, nor any of its fragments, are a threat to Earth.

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


2012-349
Posted by Nelio Inacio at 12:46 PM 0 comments

A Scroll Through Memory Lane With Cassini

A Scroll Through Memory Lane With Cassini:

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A new interactive timeline of NASA's Cassini mission at Saturn
A new interactive timeline features milestones in the journey of NASA's Cassini spacecraft.
› Launch interactive timeline


November 09, 2012

A new, interactive version of a timeline of NASA's Cassini mission to Saturn is now available online. The journey starts with launch on Oct. 15, 1997, and presents illustrated milestones and discoveries since then, including the finding of geysers on the moon Enceladus and lakes on the moon Titan. The timeline runs through the expected completion of the mission in 2017.


Experience Cassini here: http://saturn.jpl.nasa.gov/interactive/missiontimeline.


Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov

2012-353
Posted by Nelio Inacio at 12:45 PM 0 comments

NASA Study Examines Antarctic Sea Ice Increases

NASA Study Examines Antarctic Sea Ice Increases:

View of Sheldon Glacier with Mount Barre in the background
View of Sheldon Glacier with Mount Barre in the background, seen from Ryder Bay near Rothera Research Station, Adelaide Island, Antarctica. A new NASA/British Antarctic Survey study examines why Antarctic sea ice cover has increased under the effects of climate change over the past two decades.
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November 12, 2012

NASA and British Antarctic Survey scientists have reported the first direct evidence that marked changes to Antarctic sea ice drift caused by changing winds are responsible for observed increases in Antarctic sea ice cover in the past two decades. The results help explain why, unlike the dramatic sea ice losses being reported in the Arctic, Antarctic sea ice cover has increased under the effects of climate change.


Research scientists Ron Kwok of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Paul Holland of the Natural Environment Research Council's British Antarctic Survey, Cambridge, United Kingdom, used maps created by JPL from more than five million individual daily ice-motion measurements. The data, captured over a period of 19 years by four U.S. Defense Meteorological satellites, show, for the first time, long-term changes in sea ice drift around Antarctica.


"Until now, these changes in ice drift were only speculated upon, using computer models of Antarctic winds," said Holland, lead author of the study published this week in the journal Nature Geosciences. "This study of direct satellite observations shows the complexity of climate change. The total Antarctic sea ice cover is increasing slowly, but individual regions are actually experiencing much larger gains and losses that are almost offsetting each other overall.


"We now know that these regional changes are caused by changes in the winds, which, in turn, affect the ice cover through changes in both ice drift and air temperature," he continued. "The changes in ice drift also suggest large changes in the ocean surrounding Antarctica, which is very sensitive to the cold and salty water produced by sea ice growth."


Holland said sea ice around Antarctica is constantly being blown away from the continent by strong northward winds. "Since 1992, this ice drift has changed," he said. "In some areas, the export of ice away from Antarctica has doubled, while in others it has decreased significantly."


Sea ice plays a key role in Earth's environment, reflecting heat from the sun and providing a habitat for marine life. At both poles, sea ice cover is at its minimum during late summer. However, during the winter freeze in Antarctica, this ice cover expands to an area roughly twice the size of Europe. Ranging in thickness from less than three feet (a meter) to several meters, the ice insulates the warm ocean from the frigid atmosphere above.


This new research also helps explain why observed changes in the amount of sea ice cover are so different in the two polar regions. The Arctic has experienced dramatic ice losses in recent decades, while the overall ice extent in the Antarctic has increased slightly. However, this small Antarctic increase is actually the result of much larger regional increases and decreases, which are now shown to be caused by wind-driven changes. In places, increased northward winds have caused the sea ice cover to expand outwards from Antarctica. In contrast, the Arctic Ocean is surrounded by land, so changed winds cannot cause Arctic ice to expand in the same way.


"The Antarctic sea ice cover interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent," said Kwok.


Climate change has had contrasting impacts across Antarctica in recent decades. The Antarctic Peninsula has warmed as much as anywhere in the Southern Hemisphere, while East Antarctica has shown little change or even a small cooling around the coast. The new research improves understanding of present and future climate change. The authors note it is important to distinguish between the Antarctic Ice Sheet - glacial ice - which is losing volume, and Antarctic sea ice - frozen seawater - which is expanding.


The research was funded by NASA and the Natural Environment Research Council.


For more information and supporting graphics, see the full British Antarctic Survey news release at: http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=1967 .

Alan Buis 818-354-0474/Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.buis@jpl.nasa.gov


Audrey Stevens 44-0-1223-221414 (office); 07736-921693 (cell)

British Antarctic Survey, Cambridge, United Kingdom

auev@bas.ac.uk


2012-355
Posted by Nelio Inacio at 12:45 PM 0 comments

Planck Spots Colossal Intergalactic Bridge

Planck Spots Colossal Intergalactic Bridge:

Bridging Cities of Galaxies
Planck has discovered a bridge of hot gas that connects galaxy clusters Abell 399 (lower center) and Abell 401 (top left). The galaxy pair is located about a billion light-years from Earth, and the gas bridge extends approximately 10 million light-years between them. Image credits: Sunyaev-Zel'dovich effect: ESA Planck Collaboration; optical image: STScI Digitized Sky Survey
› Full image and caption


November 20, 2012

The Planck space telescope has made the first conclusive detection of a bridge of hot gas connecting a pair of galaxy clusters across 10 million light-years of intergalactic space.


"Planck is helping to reveal hidden material between galaxy clusters that we couldn't see clearly before," said James Bartlett of NASA's Jet Propulsion Laboratory, Pasadena, Calif., a member of the U.S. Planck science team. Planck is a European Space Agency mission with significant participation from NASA.


The mission's primary task is to capture the most ancient light of the cosmos, the cosmic microwave background. As this faint light traverses the universe, it encounters different types of structure, including galaxies and galaxy clusters -- assemblies of hundreds to thousands of galaxies bound together by gravity.


If the cosmic microwave background light interacts with the hot gas permeating these huge cosmic structures, its energy distribution is modified in a characteristic way, a phenomenon known as the Sunyaev-Zel'dovich effect, after the scientists who discovered it.


Astronomers using Planck and the Sunyaev-Zel'dovich effect were able to discover a bridge of hot gas connecting the clusters Abell 399 and Abell 401, each containing hundreds of galaxies.


The presence of hot gas between the clusters, which are billions of light years away, was first hinted at in X-ray data from ESA's XMM-Newton, and the new Planck data confirm the observation.


Read the full story from the European Space Agency at http://www.esa.int/SPECIALS/Planck/SEMRT791M9H_0.html .


NASA's Planck Project Office is based at JPL. JPL contributed mission-enabling technology for both of Planck's science instruments. European, Canadian and U.S. Planck scientists work together to analyze the Planck data. More information is online at http://www.nasa.gov/planck and http://www.esa.int/planck .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2012-365
Posted by Nelio Inacio at 12:44 PM 0 comments

Cassini Finds a Video Gamers' Paradise at Saturn

Cassini Finds a Video Gamers' Paradise at Saturn:

Pac-Man-like features on Saturn's moons Tethys and Mimas
Scientists with NASA's Cassini mission have spotted two features shaped like the 1980s video game icon "Pac-Man" on moons of Saturn. One was observed on the moon Mimas in 2010 and the latest was observed on the moon Tethys. Image credit: NASA/JPL-Caltech/GSFC/SWRI

› Full image and caption


November 26, 2012

You could call this "Pac-Man, the Sequel." Scientists with NASA's Cassini mission have spotted a second feature shaped like the 1980s video game icon in the Saturn system, this time on the moon Tethys. (The first was found on Mimas in 2010). The pattern appears in thermal data obtained by Cassini's composite infrared spectrometer, with warmer areas making up the Pac-Man shape.


"Finding a second Pac-Man in the Saturn system tells us that the processes creating these Pac-Men are more widespread than previously thought," said Carly Howett, the lead author of a paper recently released online in the journal Icarus. "The Saturn system - and even the Jupiter system - could turn out to be a veritable arcade of these characters."


Scientists theorize that the Pac-Man thermal shape on the Saturnian moons occurs because of the way high-energy electrons bombard low latitudes on the side of the moon that faces forward as it orbits around Saturn. The bombardment turns that part of the fluffy surface into hard-packed ice. As a result, the altered surface does not heat as rapidly in the sunshine or cool down as quickly at night as the rest of the surface, similar to how a boardwalk at the beach feels cooler during the day but warmer at night than the nearby sand. Finding another Pac-Man on Tethys confirms that high-energy electrons can dramatically alter the surface of an icy moon. Also, because the altered region on Tethys, unlike on Mimas, is also bombarded by icy particles from Enceladus' plumes, it implies the surface alteration is occurring more quickly than its recoating by plume particles.


"Studies at infrared wavelengths give us a tremendous amount of information about the processes that shape planets and moons," said Mike Flasar, the spectrometer's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md. "A result like this underscores just how powerful these observations are."


Scientists saw the new Pac-Man on Tethys in data obtained on Sept. 14, 2011, where daytime temperatures inside the mouth of Pac-Man were seen to be cooler than their surroundings by 29 degrees Fahrenheit (15 kelvins). The warmest temperature recorded was a chilly minus 300 degrees Fahrenheit (90 kelvins), which is actually slightly cooler than the warmest temperature at Mimas (about minus 290 degrees Fahrenheit, or 95 kelvins). At Tethys, unlike Mimas, the Pac-Man pattern can also be seen subtly in visible-light images of the surface, as a dark lens-shaped region. This brightness variation was first noticed by NASA's Voyager spacecraft in 1980.


"Finding a new Pac-Man demonstrates the diversity of processes at work in the Saturn system," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Future Cassini observations may reveal other new phenomena that will surprise us and help us better understand the evolution of moons in the Saturn system and beyond."


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center in Greenbelt, Md., where the instrument was built.


More information about the Cassini-Huygens mission is at: 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

Elizabeth Zubritsky 301-614-5438

Goddard Space Flight Center, Greenbelt, Md.

elizabeth.a.zubritsky@nasa.gov

2012-367
Posted by Nelio Inacio at 12:44 PM 0 comments

NASA to Host Dec. 3 Teleconference About Voyager Mission

NASA to Host Dec. 3 Teleconference About Voyager Mission:

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

› Full image and caption


November 29, 2012

PASADENA, Calif. -- NASA will host a media teleconference at 11 a.m. PST (2 p.m. EST) on Monday, Dec. 3, to discuss the latest findings and travels of NASA's Voyager 1 spacecraft.


Voyager 1 and its twin, Voyager 2, have been speeding through the outer reaches of our solar system and sending back unprecedented data about the bubble of charged particles around our sun. They were launched in 1977 and have traveled farther from Earth than any other spacecraft.


Audio and visuals of the event will be streamed live online at: http://www.ustream.tv/nasajpl2 .


For more information about the Voyager mission, visit: http://www.nasa.gov/voyager and http://voyager.jpl.nasa.gov .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov

Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov

2012-379b
Posted by Nelio Inacio at 12:43 PM 0 comments

NASA hosts Dec. 13 Telecon on Twin Probes' Mission-Ending Moon Impact

NASA hosts Dec. 13 Telecon on Twin Probes' Mission-Ending Moon Impact:

Artist concept of GRAIL mission. Grail will fly twin spacecraft in tandem orbits around the moon to measure its gravity field in unprecedented detail.
Artist concept of GRAIL mission. Grail will fly twin spacecraft in tandem orbits around the moon to measure its gravity field in unprecedented detail. Image credit: NASA/JPL

› Larger image


December 10, 2012

PASADENA, Calif. -- NASA will host a media teleconference at 10:30 a.m. PST (1:30 p.m. EST) Thursday, Dec. 13, to provide an overview of events leading up to twin spacecraft being commanded to impact the moon's surface on Dec. 17 at approximately 2:28 p.m. PST (5:28 p.m. EST).


NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission, whose two washing machine-sized probes were named Ebb and Flow by elementary school students in Bozeman, Mont., via a nationwide contest, have successfully completed their prime missions and have only days to go on their extended mission science collection. As planned, the duo is running low on fuel. They have been orbiting the moon since New Year's Eve and New Year's Day, respectively, giving scientists unprecedented detail about the moon's internal structure and composition.


Visuals will be available at the start of the event at: http://bit.ly/grail20121213 .


Audio and visuals of the event will be streamed live online at:
http://www.nasa.gov/newsaudio and http://www.ustream.tv/nasajpl2 .

For more information about the mission, visit: http://www.nasa.gov/grail

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


2012-391b
Posted by Nelio Inacio at 12:42 PM 0 comments

Shot Away from its Companion, Giant Star Makes Waves

Shot Away from its Companion, Giant Star Makes Waves:

Massive Star Makes Waves
The giant star Zeta Ophiuchi is having a "shocking" effect on the surrounding dust clouds in this infrared image from NASA's Spitzer Space Telescope. Stellar winds flowing out from this fast-moving star are making ripples in the dust as it approaches, creating a bow shock seen as glowing gossamer threads, which, for this star, are only seen in infrared light. Image credit: NASA/JPL-Caltech
› Full image and caption


December 18, 2012

Like a ship plowing through still waters, the giant star Zeta Ophiuchi is speeding through space, making waves in the dust ahead. NASA's Spitzer Space Telescope has captured a dramatic, infrared portrait of these glowing waves, also known as a bow shock.


Astronomers theorize that this star was once sitting pretty next to a companion star even heftier than itself. But when that star exploded, Zeta Ophiuchi was kicked away and sent flying. Zeta Ophiuchi, which is 20 times more massive and 80,000 times brighter than our sun, is racing along at about 54,000 mph (24 kilometers per second).


In this view, infrared light that we can't see with our eyes has been assigned visible colors. Zeta Ophiuchi appears as the bright blue star at center. As it charges through the dust, which appears green, fierce stellar winds push the material into waves. Where the waves are the most compressed, and the warmest, they appear red. This bow shock is analogous to the ripples that precede the bow of a ship as it moves through the water, or the pileup of air ahead of a supersonic airplane that results in a sonic boom.


NASA's Wide-field Infrared Survey Explorer, or WISE, released a similar picture of the same object in 2011. WISE sees infrared light as does Spitzer, but WISE was an all-sky survey designed to take snapshots of the entire sky. Spitzer, by contrast, observes less of the sky, but in more detail. The WISE image can be seen at: http://www.jpl.nasa.gov/news/news.php?release=2011-026 .


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


2013-403
Posted by Nelio Inacio at 12:40 PM 0 comments

From Cassini for the Holidays: A Splendor Seldom Seen

From Cassini for the Holidays: A Splendor Seldom Seen:

A Splendor Seldom Seen
NASA's Cassini spacecraft has delivered a glorious view of Saturn, taken while the spacecraft was in Saturn's shadow. The cameras were turned toward Saturn and the sun so that the planet and rings are backlit. Image Credit: NASA/JPL-Caltech/Space Science Institute
› Full image and caption


December 18, 2012

PASADENA, Calif -- Just in time for the holidays, NASA's Cassini spacecraft, in orbit around Saturn for more than eight years now, has delivered another glorious, backlit view of the planet Saturn and its rings.


On Oct. 17, 2012, during its 174th orbit around the gas giant, Cassini was deliberately positioned within Saturn's shadow, a perfect location from which to look in the direction of the sun and take a backlit view of the rings and the dark side of the planet. Looking back towards the sun is a geometry referred to by planetary scientists as "high solar phase;" near the center of your target's shadow is the highest phase possible. This is a very scientifically advantageous and coveted viewing position, as it can reveal details about both the rings and atmosphere that cannot be seen in lower solar phase.


The last time Cassini had such an unusual perspective on Saturn and its rings, at sufficient distance and with sufficient time to make a full system mosaic, occurred in September 2006, when it captured a mosaic, processed to look like natural color, entitled "In Saturn's Shadow" (http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA08329). In that mosaic, planet Earth put in a special appearance, making "In Saturn's Shadow" one of the most popular Cassini images to date.


The mosaic being released today by the mission and the imaging team, in celebration of the 2012 holiday season, does not contain Earth; along with the sun, our planet is hidden behind Saturn. However, it was taken when Cassini was closer to Saturn and therefore shows more detail in the rings than the one taken in 2006.


The new processed mosaic, composed of 60 images taken in the violet, visible and near infrared part of the spectrum, can be found at http://www.nasa.gov/cassini , http://saturn.jpl.nasa.gov and http://ciclops.org .


"Of all the many glorious images we have received from Saturn, none are more strikingly unusual than those taken from Saturn's shadow," said Carolyn Porco, Cassini's imaging team lead based at the Space Science Institute in Boulder, Colo.


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.

Jia-Rui C. 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


2012-402
Posted by Nelio Inacio at 12:40 PM 0 comments

One Million Downloads for JPL Space Images App

One Million Downloads for JPL Space Images App:

1 Million Downloads Caption text
NASA/JPL's popular mobile app continues to amass many exciting images including the Mars Curiosity Rover, dying stars, moons of Saturn and giant asteroids. Image credit: NASA/JPL-Caltech
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December 20, 2012

Space Images, the mobile image application from NASA's Jet Propulsion Laboratory that puts visuals direct from space missions at users' fingertips, has reached 1 million downloads.


Just this year the app amassed a cadre of exciting images from many of the laboratory's missions including the Mars Curiosity rover, which made a dramatic landing on Mars in August and has sent back many novel views of the Red Planet.
Vibrant explosions from dying stars, the elegant choreography of Saturn's moons, and the scarred and cratered surface of a giant asteroid are just a few of the other scenes users can discover by downloading the app.


Chosen as a Staff Favorite in the Apple App Store shortly after its release in 2010, Space Images is now in Version 2, featuring videos and 3-D image collections and more extensive sharing options. The app is available free on both Android and Apple devices as well as online on the Space Images website at http://www.jpl.nasa.gov/spaceimages/.


Visit http://bit.ly/Ym9ir1 to download Space Images for Apple devices and http://bit.ly/T85EfG for Android devices. Explore more mobile offerings from JPL at http://www.jpl.nasa.gov/apps.

Elena Mejia 818-393-5467

Jet Propulsion Laboratory, Pasadena, Calif.

Elena.Mejia@jpl.nasa.gov

2012-407
Posted by Nelio Inacio at 12:40 PM 0 comments

Picture This: Vesta's Dark Materials in Dawn's View

Picture This: Vesta's Dark Materials in Dawn's View:

This composite-color view from NASA's Dawn mission shows Cornelia Crater, streaked with dark materials, on the giant asteroid Vesta.
This composite-color view from NASA's Dawn mission shows Cornelia Crater, streaked with dark materials, on the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
› Full image and caption


January 03, 2013

A new study of images from NASA's Dawn mission examines remarkable, dark-as-coal material that speckles the surface of the giant asteroid Vesta. Scientists are using the images, taken by Dawn's framing camera, to understand the impact environment early in Vesta's evolution.


In the most comprehensive analysis of the dark material to date, Dawn scientists describe how this carbon-rich material tends to appear around the edges of two giant impact basins in Vesta's southern hemisphere. The analysis suggests that the dark material was most likely delivered by the object that created the older of the two basins, known as Veneneia, about 2 to 3 billion years ago. Some of those materials were later covered up by the impact that created the younger basin, Rheasilvia.


The paper, published in the November-December issue of the journal Icarus, was led by Vishnu Reddy of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, and the University of North Dakota, Grand Forks. More information on the paper is available at: http://www.mpg.de/en .


The Dawn spacecraft orbited Vesta for more than a year, departing in September 2012. Dawn is now on its way to the dwarf planet Ceres, and will arrive in early 2015.


More information on Dawn is available at: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .


The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. The University of California, Los Angeles, is responsible for overall Dawn mission science. The Dawn framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, with significant contributions by DLR German Aerospace Center, Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The framing camera project is funded by the Max Planck Society, DLR and NASA.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


2013-001
Posted by Nelio Inacio at 12:39 PM 0 comments

NASA's NuSTAR Catches Black Holes in Galaxy Web

NASA's NuSTAR Catches Black Holes in Galaxy Web:

Blazing Black Holes Spotted in Spiral Beauty
This new view of spiral galaxy IC 342, also known as Caldwell 5, includes data from NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. High-energy X-ray data from NuSTAR have been translated to the color magenta, and superimposed on a visible-light view highlighting the galaxy and its star-studded arms. NuSTAR is the first orbiting telescope to take focused pictures of the cosmos in high-energy X-ray light; previous observations of this same galaxy taken at similar wavelengths blurred the entire object into one pixel. Image credit: NASA/JPL-Caltech/DSS
› Full image and caption

January 07, 2013

PASADENA, Calif. - NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, set its X-ray eyes on a spiral galaxy and caught the brilliant glow of two black holes lurking inside.


The new image is being released Monday along with NuSTAR's view of the supernova remnant Cassiopeia A, at the American Astronomical Society meeting in Long Beach, Calif.


"These new images showcase why NuSTAR is giving us an unprecedented look at the cosmos," said Lou Kaluzienski, NuSTAR program scientist at NASA headquarters in Washington. "With NuSTAR's greater sensitivity and imaging capability, we're getting a wealth of new information on a wide array of cosmic phenomena in the high-energy X-ray portion of the electromagnetic spectrum."


Launched last June, NuSTAR is the first orbiting telescope with the ability to focus high-energy X-ray light. It can view objects in considerably greater detail than previous missions operating at similar wavelengths. Since launch, the NuSTAR team has been fine-tuning the telescope, which includes a mast the length of a school bus connecting the mirrors and detectors.


The mission has looked at a range of extreme, high-energy objects already, including black holes near and far, and the incredibly dense cores of dead stars. In addition, NuSTAR has begun black hole searches in the inner region of the Milky Way galaxy and in distant galaxies in the universe.


Among the telescope's targets is the spiral galaxy IC342, also known as Caldwell 5, featured in one of the two new images. This galaxy lies 7 million light-years away in the constellation Camelopardalis (the Giraffe). Previous X-ray observations of the galaxy from NASA's Chandra X-ray Observatory revealed the presence of two blinding black holes, called ultraluminous X-ray sources (ULXs).


How ULXs can shine so brilliantly is an ongoing mystery in astronomy. While these black holes are not as powerful as the supermassive black hole at the hearts of galaxies, they are more than 10 times brighter than the stellar-mass black holes peppered among the stars in our own galaxy. Astronomers think ULXs could be less common intermediate-mass black holes, with a few thousand times the mass of our sun, or smaller stellar-mass black holes in an unusually bright state. A third possibility is that these black holes don't fit neatly into either category.


"High-energy X-rays hold a key to unlocking the mystery surrounding these objects," said Fiona Harrison, NuSTAR principal investigator at the California Institute of Technology in Pasadena. "Whether they are massive black holes, or there is new physics in how they feed, the answer is going to be fascinating."


In the image, the two bright spots that appear entangled in the arms of the IC342 galaxy are the black holes. High-energy X-ray light has been translated into the color magenta, while the galaxy itself is shown in visible light.


"Before NuSTAR, high-energy X-ray pictures of this galaxy and the two black holes would be so fuzzy that everything would appear as one pixel," said Harrison.


The second image features the well-known, historical supernova remnant Cassiopeia A, located 11,000 light-years away in the constellation Cassiopeia. The color blue indicates the highest-energy X-ray light seen by NuSTAR, while red and green signify the lower end of NuSTAR's energy range. The blue region is where the shock wave from the supernova blast is slamming into material surrounding it, accelerating particles to nearly the speed of light. As the particles speed up, they give off a type of light known as synchrotron radiation. NuSTAR will be able to determine for the first time how energetic the particles are, and address the mystery of what causes them to reach such great speeds.


"Cas A is the poster child for studying how massive stars explode and also provides us a clue to the origin of the high-energy particles, or cosmic rays, that we see here on Earth," said Brian Grefenstette of Caltech, a lead researcher on the observations. "With NuSTAR, we can study where, as well as how, particles are accelerated to such ultra-relativistic energies in the remnant left behind by the supernova explosion."


For more information about NuSTAR and to view the new images, visit: http://www.nasa.gov/nustar .


NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory in Pasadena for NASA's Science Mission Directorate in Washington. Orbital Sciences Corporation of Dulles, Va., built the spacecraft. Its instrument was built by a consortium including Caltech; JPL; the University of California (UC) Berkeley; Columbia University; NASA's Goddard Space Flight Center in Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory in Livermore, Calif.; and ATK Aerospace Systems of Goleta, Calif.
NuSTAR's mission operations center is at UC Berkeley, with the Italian Space Agency providing an equatorial ground station located at Malindi, Kenya. The mission's outreach program is based at Sonoma State University in Rohnert Park, Calif. Goddard manages NASA's Explorer Program. Caltech manages JPL for NASA.


You can follow JPL News on Facebook at: http://www.facebook.com/nasajpl and on Twitter at: http://www.twitter.com/nasajpl . Caltech manages JPL for NASA.

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


2013-008
Posted by Nelio Inacio at 12:39 PM 0 comments

NASA's Kepler Discovers 461 New Planet Candidates

NASA's Kepler Discovers 461 New Planet Candidates:

Size of Kepler Planet Candidates
Since the last Kepler catalog was released in February 2012, the number of candidates discovered in the Kepler data has increased by 20 percent and now totals 2,740 potential planets orbiting 2,036 stars. Based on observations conducted May 2009 to March 2011, the most dramatic increases are seen in the number of Earth-size and super Earth-size candidates discovered, which grew by 43 and 21 percent respectively. Image credit: NASA/Ames/JPL-Caltech
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January 07, 2013

PASADENA, Calif. - NASA's Kepler mission Monday announced the discovery of 461 new planet candidates. Four of the potential new planets are less than twice the size of Earth and orbit in their sun's "habitable zone," the region in the planetary system where liquid water might exist on the surface of a planet.


Based on observations conducted from May 2009 to March 2011, the findings show a steady increase in the number of smaller-size planet candidates and the number of stars with more than one candidate.


"There is no better way to kick off the start of the Kepler extended mission than to discover more possible outposts on the frontier of potentially life-bearing worlds," said Christopher Burke, Kepler scientist at the SETI Institute in Mountain View, Calif., who is leading the analysis.


Since the last Kepler catalog was released in February 2012, the number of candidates discovered in the Kepler data has increased by 20 percent and now totals 2,740 potential planets orbiting 2,036 stars. The most dramatic increases are seen in the number of Earth-size and super Earth-size candidates discovered, which grew by 43 and 21 percent respectively.


The new data increase the number of stars discovered to have more than one planet candidate from 365 to 467. Today, 43 percent of Kepler's planet candidates are observed to have neighbor planets.


"The large number of multi-candidate systems being found by Kepler implies that a substantial fraction of exoplanets reside in flat multi-planet systems," said Jack Lissauer, planetary scientist at NASA's Ames Research Center in Moffett Field, Calif. "This is consistent with what we know about our own planetary neighborhood."


The Kepler space telescope identifies planet candidates by repeatedly measuring the change in brightness of more than 150,000 stars in search of planets that pass in front of, or "transit," their host star. At least three transits are required to verify a signal as a potential planet.


Scientists analyzed more than 13,000 transit-like signals to eliminate known spacecraft instrumentation and astrophysical false positives, phenomena that masquerade as planetary candidates, to identify the potential new planets.


Candidates require additional follow-up observations and analyses to be confirmed as planets. At the beginning of 2012, 33 candidates in the Kepler data had been confirmed as planets. Today, there are 105.


"The analysis of increasingly longer time periods of Kepler data uncovers smaller planets in longer period orbits-- orbital periods similar to Earth's," said Steve Howell, Kepler mission project scientist at Ames. "It is no longer a question of will we find a true Earth analogue, but a question of when."


The complete list of Kepler planet candidates is available in an interactive table at the NASA Exoplanet Archive. The archive is funded by NASA's Exoplanet Exploration Program to collect and make public data to support the search for and characterization of exoplanets and their host stars.


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 in Washington.


JPL manages NASA's Exoplanet Exploration Program. The NASA Exoplanet Archive is hosted at the Infrared Processing and Analysis Center at the California Institute of Technology.


For information about the NASA Exoplanet Archive, visit: http://exoplanetarchive.ipac.caltech.edu/index.html .


For information about the Kepler mission, visit: http://www.nasa.gov/kepler .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


J.D. Harrington 202-358-5241

NASA Headquarters, Washington

j.d.harrington@nasa.gov


Michele Johnson 650-604-4789

Ames Research Center, Moffett Field, Calif.

michele.johnson@nasa.gov


2012-005
Posted by Nelio Inacio at 12:38 PM 0 comments

Wednesday, July 30, 2014

NASA's Galex Reveals the Largest-Known Spiral Galaxy

NASA's Galex Reveals the Largest-Known Spiral Galaxy:

This composite of the giant barred spiral galaxy NGC 6872 combines visible light
This composite of the giant barred spiral galaxy NGC 6872 combines visible light images from the European Southern Observatory's Very Large Telescope with far-ultraviolet (1,528 angstroms) data from NASA's GALEX and 3.6-micron infrared data acquired by NASA's Spitzer Space Telescope. Image credit: NASA's Goddard Space Flight Center/ESO/JPL-Caltech/DSS
› Full image and caption

January 10, 2013

PASADENA, Calif. -- The spectacular barred spiral galaxy NGC 6872 has ranked among the biggest stellar systems for decades. Now a team of astronomers from the United States, Chile and Brazil has crowned it the largest known spiral, based on archival data from NASA's Galaxy Evolution Explorer (GALEX) mission, which has since been loaned to the California Institute of
Technology in Pasadena.


Measuring tip-to-tip across its two outsized spiral arms, NGC 6872 spans more than 522,000 light-years, making it more than five times the size of our Milky Way galaxy.


"Without GALEX's ability to detect the ultraviolet light of the youngest, hottest stars, we would never have recognized the full extent of this intriguing system," said lead scientist Rafael Eufrasio, a research assistant at NASA's Goddard Space Flight Center in Greenbelt, Md., who is a doctoral student at Catholic University of America in Washington. He presented the findings Thursday at the American Astronomical Society meeting in Long Beach, Calif.


The galaxy's unusual size and appearance stem from its interaction with a much smaller disk galaxy named IC 4970, which has only about one-fifth the mass of NGC 6872. The odd couple is located 212 million light-years from Earth in the southern constellation Pavo.


Astronomers think large galaxies, including our own, grew through mergers and acquisitions -- assembling over billions of years by absorbing numerous smaller systems.


Intriguingly, the gravitational interaction of NGC 6872 and IC 4970 may have done the opposite, spawning what may develop into a new small galaxy.


"The northeastern arm of NGC 6872 is the most disturbed and is rippling with star formation, but at its far end, visible only in the ultraviolet, is an object that appears to be a tidal dwarf galaxy similar to those seen in other interacting systems," said team member Duilia de Mello, a professor of astronomy at Catholic University.


The tidal dwarf candidate is brighter in ultraviolet than other regions of the galaxy, a sign it bears a rich supply of hot young stars less than 200 million years old.


The researchers studied the galaxy across the spectrum using archival data from the European Southern Observatory's Very Large Telescope, the Two Micron All Sky Survey, and NASA's Spitzer Space Telescope, as well as GALEX.


By analyzing the distribution of energy by wavelength, the team uncovered a distinct pattern of stellar age along the galaxy's two prominent spiral arms. The youngest stars appear in the far end of the northwestern arm, within the tidal dwarf candidate, and stellar ages skew progressively older toward the galaxy's center.


The southwestern arm displays the same pattern, which is likely connected to waves of star formation triggered by the galactic encounter.


A 2007 study by Cathy Horellou at Onsala Space Observatory in Sweden and Baerbel Koribalski of the Australia National Telescope Facility developed computer simulations of the collision that reproduced the overall appearance of the system as we see it today. According to the closest match, IC 4970 made its closest approach about 130 million years ago and followed a path that took it nearly along the plane of the spiral's disk in the same direction it rotates. The current study is consistent with this picture.


As in all barred spirals, NGC 6872 contains a stellar bar component that transitions between the spiral arms and the galaxy's central regions. Measuring about 26,000 light-years in radius, or about twice the average length found in nearby barred spirals, it is a bar that befits a giant galaxy.


The team found no sign of recent star formation along the bar, which indicates it formed at least a few billion years ago. Its aged stars provide a fossil record of the galaxy's stellar population before the encounter with IC 4970 stirred things up.


"Understanding the structure and dynamics of nearby interacting systems like this one brings us a step closer to placing these events into their proper cosmological context, paving the way to decoding what we find in younger, more distant systems," said team member and Goddard astrophysicist Eli Dwek.


The study also included Fernanda Urrutia-Viscarra and Claudia Mendes de Oliveira at the University of Sao Paulo in Brazil and Dimitri Gadotti at the European Southern Observatory in Santiago, Chile.


The GALEX mission is led by the California Institute of Technology in Pasadena, which is responsible for science operations and data analysis. NASA's Jet Propulsion Laboratory, also in Pasadena, manages the mission and built the science instrument. GALEX was developed under NASA's Explorers Program managed by NASA's Goddard Space Flight Center. In May 2012, NASA loaned GALEX to Caltech, which continues spacecraft operations and data management using private funds.


For more information about GALEX, visit http://www.nasa.gov/galex and http://www.galex.caltech.edu/ .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


Lynn Chandler 301-286-2806

Goddard Space Flight Center, Greenbelt, Md.

lynn.chandler-1@nasa.gov


J.D. Harrington 202-358-5241

Headquarters, Washington

j.d.harrington@nasa.gov


2013-016
Posted by Nelio Inacio at 6:05 AM 0 comments

Study Finds Severe Climate Jeopardizing Amazon Forest

Study Finds Severe Climate Jeopardizing Amazon Forest:

At left, the extent of the 2005 megadrought in the western Amazon rainforests during the summer months of June
At left, the extent of the 2005 megadrought in the western Amazon rainforests during the summer months of June, July and August as measured by NASA satellites. The most impacted areas are shown in shades of red and yellow. The circled area in the right panel shows the extent of the forests that experienced slow recovery from the 2005 drought, with areas in red and yellow shades experiencing the slowest recovery. Image credit: NASA/JPL-Caltech/GSFC

› Larger image

January 17, 2013

PASADENA, Calif. - An area of the Amazon rainforest twice the size of California continues to suffer from the effects of a megadrought that began in 2005, finds a new NASA-led study. These results, together with observed recurrences of droughts every few years and associated damage to the forests in southern and western Amazonia in the past decade, suggest these rainforests may be showing the first signs of potential large-scale degradation due to climate change.


An international research team led by Sassan Saatchi of NASA's Jet Propulsion Laboratory, Pasadena, Calif., analyzed more than a decade of satellite microwave radar data collected between 2000 and 2009 over Amazonia. The observations included measurements of rainfall from NASA's Tropical Rainfall Measuring Mission and measurements of the moisture content and structure of the forest canopy (top layer) from the Seawinds scatterometer on NASA's QuikScat spacecraft.


The scientists found that during the summer of 2005, more than 270,000 square miles (700,000 square kilometers, or 70 million hectares) of pristine, old-growth forest in southwestern Amazonia experienced an extensive, severe drought. This megadrought caused widespread changes to the forest canopy that were detectable by satellite. The changes suggest dieback of branches and tree falls, especially among the older, larger, more vulnerable canopy trees that blanket the forest.


While rainfall levels gradually recovered in subsequent years, the damage to the forest canopy persisted all the way to the next major drought, which began in 2010. About half the forest affected by the 2005 drought - an area the size of California - did not recover by the time QuikScat stopped gathering global data in November 2009 and before the start of a more extensive drought in 2010.


"The biggest surprise for us was that the effects appeared to persist for years after the 2005 drought," said study co-author Yadvinder Malhi of the University of Oxford, United Kingdom. "We had expected the forest canopy to bounce back after a year with a new flush of leaf growth, but the damage appeared to persist right up to the subsequent drought in 2010."


Recent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate change. Satellite and ground data have shown an increase in wildfires during drought years and tree die-offs following severe droughts. Until now, there had been no satellite-based assessment of the multi-year impacts of these droughts across all of Amazonia. Large-scale droughts can lead to sustained releases of carbon dioxide from decaying wood, affecting ecosystems and Earth's carbon cycle.


The researchers attribute the 2005 Amazonian drought to the long-term warming of tropical Atlantic sea surface temperatures. "In effect, the same climate phenomenon that helped form hurricanes Katrina and Rita along U.S. southern coasts in 2005 also likely caused the severe drought in southwest Amazonia," Saatchi said. "An extreme climate event caused the drought, which subsequently damaged the Amazonian trees."


Saatchi said such megadroughts can have long-lasting effects on rainforest ecosystems. "Our results suggest that if droughts continue at five- to 10-year intervals or increase in frequency due to climate change, large areas of the Amazon forest are likely to be exposed to persistent effects of droughts and corresponding slow forest recovery," he said. "This may alter the structure and function of Amazonian rainforest ecosystems."


The team found that the area affected by the 2005 drought was much larger than scientists had previously predicted. About 30 percent (656,370 square miles, or 1.7 million square kilometers) of the Amazon basin's total current forest area was affected, with more than five percent of the forest experiencing severe drought conditions. The 2010 drought affected nearly half of the entire Amazon forest, with nearly a fifth of it experiencing severe drought. More than 231,660 square miles (600,000 square kilometers) of the area affected by the 2005 drought were also affected by the 2010 drought. This "double whammy" by successive droughts suggests a potentially long-lasting and widespread effect on forests in southern and western Amazonia.


The drought rate in Amazonia during the past decade is unprecedented over the past century. In addition to the two major droughts in 2005 and 2010, the area has experienced several localized mini-droughts in recent years. Observations from ground stations show that rainfall over the southern Amazon rainforest declined by almost 3.2 percent per year in the period from 1970 to 1998. Climate analyses for the period from 1995 to 2005 show a steady decline in water availability for plants in the region. Together, these data suggest a decade of moderate water stress led up to the 2005 drought, helping trigger the large-scale forest damage seen following the 2005 drought.


Saatchi said the new study sheds new light on a major controversy that existed about how the Amazon forest responded following the 2005 megadrought. Previous studies using conventional optical satellite data produced contradictory results, likely due to the difficulty of correcting the optical data for interference by clouds and other atmospheric conditions.


In contrast, QuikScat's scatterometer radar was able to see through the clouds and penetrate into the top few meters of vegetation, providing daily measurements of the forest canopy structure and estimates of how much water the forest contains. Areas of drought-damaged forest produced a lower radar signal than the signals collected over healthy forest areas, indicating either that the forest canopy is drier or it is less "rough" due to damage to or the death of canopy trees.


Results of the study were published recently in the Proceedings of the National Academy of Sciences. Other participating institutions included UCLA; University of Oxford, United Kingdom; University of Exeter, Devon, United Kingdom; National Institute for Space Research, Sao Jose dos Campos, Sao Paulo, Brazil; Boston University, Mass.; and NASA's Ames Research Center, Moffett Field, Calif.


For more on NASA's scatterometry missions, visit: http://winds.jpl.nasa.gov/index.cfm . You can follow JPL News on Facebook at: http://www.facebook.com/nasajpl and on Twitter at: http://www.twitter.com/nasajpl . 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


2013-025
Posted by Nelio Inacio at 6:04 AM 0 comments
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