Sunday, August 3, 2014

NASA's Spitzer Images Out-of-This-World Galaxy

NASA's Spitzer Images Out-of-This-World Galaxy:

NASA's Spitzer Space Telescope has imaged a coiled galaxy with an eye-like object at its center.
The "eye" at the center of the galaxy is actually a monstrous black hole surrounded by a ring of stars.

› Full image and caption


July 23, 2009

PASADENA, Calif. -- NASA's Spitzer Space Telescope has imaged a wild creature of the dark -- a coiled galaxy with an eye-like object at its center.


The galaxy, called NGC 1097, is located 50 million light-years away. It is spiral-shaped like our Milky Way, with long, spindly arms of stars. The "eye" at the center of the galaxy is actually a monstrous black hole surrounded by a ring of stars. In this color-coded infrared view from Spitzer, the area around the invisible black hole is blue and the ring of stars, white.


The black hole is huge, about 100 million times the mass of our sun, and is feeding off gas and dust along with the occasional unlucky star. Our Milky Way's central black hole is tame by comparison, with a mass of a few million suns.


"The fate of this black hole and others like it is an active area of research," said George Helou, deputy director of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena. "Some theories hold that the black hole might quiet down and eventually enter a more dormant state like our Milky Way black hole."


The ring around the black hole is bursting with new star formation. An inflow of material toward the central bar of the galaxy is causing the ring to light up with new stars.


"The ring itself is a fascinating object worthy of study because it is forming stars at a very high rate," said Kartik Sheth, an astronomer at NASA's Spitzer Science Center. Sheth and Helou are part of a team that made the observations.


In the Spitzer image, infrared light with shorter wavelengths is blue, while longer-wavelength light is red. The galaxy's red spiral arms and the swirling spokes seen between the arms show dust heated by newborn stars. Older populations of stars scattered through the galaxy are blue. The fuzzy blue dot to the left, which appears to fit snuggly between the arms, is a companion galaxy.


"The companion galaxy that looks as if it's playing peek-a-boo through the larger galaxy could have plunged through, poking a hole," said Helou. "But we don't know this for sure. It could also just happen to be aligned with a gap in the arms."


Other dots in the picture are either nearby stars in our galaxy, or distant galaxies.


This image was taken during Spitzer's "cold mission," which lasted more than five-and-a-half years. The telescope ran out of coolant needed to chill its infrared instruments on May 15, 2009. Two of its infrared channels will still work perfectly during the new "warm mission," which is expected to begin in a week or so, once the observatory has been recalibrated and warms to its new temperature of around 30 Kelvin (about minus 406 degrees Fahrenheit).


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, also in Pasadena. Caltech manages JPL for NASA. Spitzer's infrared array camera, which made the observations, was built by NASA's Goddard Space Flight Center, Greenbelt, Md. The instrument's principal investigator is Giovanni Fazio of the Harvard-Smithsonian Center for Astrophysics.


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

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov
2009-114
Posted by Nelio Inacio at 7:08 PM 0 comments

NASA's Moon Mapper Beholds Home

NASA's Moon Mapper Beholds Home:

false-color image of Earth, seen from moon
This false-color image of Earth was taken from 200 kilometers (124 miles) above the lunar surface was taken by the Moon Mineralogy Mapper, one of two NASA instruments onboard the Indian Space Research Organization's Chandrayaan-1 spacecraft.
Full image and caption


August 03, 2009

This image of Earth taken from 200 kilometers (124 miles) above the lunar surface was taken by the Moon Mineralogy Mapper, one of two NASA instruments onboard the Indian Space Research Organization's Chandrayaan-1 spacecraft. Australia is visible in the lower center of the image. The image is presented as a false-color composite with oceans a dark blue, clouds white, and vegetation an enhanced green. The image data were acquired on July 22, 2009.


The Moon Mineralogy Mapper instrument is a state-of-the-art imaging spectrometer designed to provide the first map of the entire lunar surface at high spatial and spectral resolution. Scientists will use this information to answer questions about the moon's origin and development and the evolution of terrestrial planets in the early solar system. Future astronauts will use it to locate resources, possibly including water, that can support exploration of the moon and beyond.


The Moon Mineralogy Mapper was selected as a Mission of Opportunity through the NASA Discovery Program. Carle Pieters of Brown University, Providence, R.I., is the principal investigator and has oversight of the instrument as a whole, as well as the Moon Mineralogy Mapper Science Team. NASA's Jet Propulsion Laboratory, Pasadena, Calif., designed and built the Moon Mineralogy Mapper and is home to its project manager, Mary White. JPL manages the program for NASA's Science Mission Directorate, Washington. The Chandrayaan-1 spacecraft was constructed, launched, and is operated by the Indian Space Research Organisation.


More information about Chandrayaan-1 is at :


http://www.isro.org/Chandrayaan .


More information about NASA's Moon Mineralogy Mapper is at :


http://m3.jpl.nasa.gov .

Media contact: DC Agle/JPL
818-393-9011
Posted by Nelio Inacio at 7:07 PM 0 comments

Glint of Sunlight Confirms Liquid in Northern Lake District of Titan

Glint of Sunlight Confirms Liquid in Northern Lake District of Titan:

This image shows the first flash of sunlight reflected off a lake on Saturn's moon Titan.
This image shows the first flash of sunlight reflected off a lake on Saturn's moon Titan. › Full image and caption


December 17, 2009

PASADENA, Calif. -- NASA's Cassini Spacecraft has captured the first flash of sunlight reflected off a lake on Saturn's moon Titan, confirming the presence of liquid on the part of the moon dotted with many large, lake-shaped basins.

Cassini scientists had been looking for the glint, also known as a specular reflection, since the spacecraft began orbiting Saturn in 2004. But Titan's northern hemisphere, which has more lakes than the southern hemisphere, has been veiled in winter darkness. The sun only began to directly illuminate the northern lakes recently as it approached the equinox of August 2009, the start of spring in the northern hemisphere. Titan's hazy atmosphere also blocked out reflections of sunlight in most wavelengths. This serendipitous image was captured on July 8, 2009, using Cassini's visual and infrared mapping spectrometer.

The new infrared image is available online at: http://www.nasa.gov/cassini, http://saturn.jpl.nasa.gov and http://wwwvims.lpl.arizona.edu.

This image will be presented Friday, Dec. 18, at the fall meeting of the American Geophysical Union in San Francisco.

"This one image communicates so much about Titan -- thick atmosphere, surface lakes and an otherworldliness," said Bob Pappalardo, Cassini project scientist, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It's an unsettling combination of strangeness yet similarity to Earth. This picture is one of Cassini's iconic images."

Titan, Saturn's largest moon, has captivated scientists because of its many similarities to Earth. Scientists have theorized for 20 years that Titan's cold surface hosts seas or lakes of liquid hydrocarbons, making it the only other planetary body besides Earth believed to harbor liquid on its surface. While data from Cassini have not indicated any vast seas, they have revealed large lakes near Titan's north and south poles.

In 2008, Cassini scientists using infrared data confirmed the presence of liquid in Ontario Lacus, the largest lake in Titan's southern hemisphere. But they were still looking for the smoking gun to confirm liquid in the northern hemisphere, where lakes are also larger.

Katrin Stephan, of the German Aerospace Center (DLR) in Berlin, an associate member of the Cassini visual and infrared mapping spectrometer team, was processing the initial image and was the first to see the glint on July 10th.

"I was instantly excited because the glint reminded me of an image of our own planet taken from orbit around Earth, showing a reflection of sunlight on an ocean," Stephan said. "But we also had to do more work to make sure the glint we were seeing wasn't lightning or an erupting volcano."

Team members at the University of Arizona, Tucson, processed the image further, and scientists were able to compare the new image to radar and near-infrared-light images acquired from 2006 to 2008.




They were able to correlate the reflection to the southern shoreline of a lake called Kraken Mare. The sprawling Kraken Mare covers about 400,000 square kilometers (150,000 square miles), an area larger than the Caspian Sea, the largest lake on Earth. It is located around 71 degrees north latitude and 337 degrees west latitude.

The finding shows that the shoreline of Kraken Mare has been stable over the last three years and that Titan has an ongoing hydrological cycle that brings liquids to the surface, said Ralf Jaumann, a visual and infrared mapping spectrometer team member who leads the scientists at the DLR who work on Cassini. Of course, in this case, the liquid in the hydrological cycle is methane rather than water, as it is on Earth.

"These results remind us how unique Titan is in the solar system," Jaumann said. "But they also show us that liquid has a universal power to shape geological surfaces in the same way, no matter what the liquid is."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jia-rui.c.cook@jpl.nasa.gov

2009-199
Posted by Nelio Inacio at 7:07 PM 0 comments

Keck Telescopes Gaze into Young Star's 'Life Zone.'

Keck Telescopes Gaze into Young Star's 'Life Zone.':

Planets form around a young star in this artist's concept. Using the Keck Interferometer in Hawaii, astronomers have probed the structure of a dust disk around MWC 419 to within 50 million miles of the star. Credit: David A. Hardy/www.astroart.org
Planets form around a young star in this artist's concept. Using the Keck Interferometer in Hawaii, astronomers have probed the structure of a dust disk around MWC 419 to within 50 million miles of the star. Credit: David A. Hardy/http://www.astroart.org

› Larger image


December 23, 2009

The inner regions of young planet-forming disks offer information about how worlds like Earth form, but not a single telescope in the world can see them. Now, for the first time, astronomers using the W. M. Keck Observatory in Hawaii have measured the properties of a young solar system at distances closer to the star than Venus is from our sun.


To achieve the feat, the team used the Keck Interferometer to combine infrared light gathered by both of the observatory's twin 10-meter (33-foot) telescopes, which are separated by 85 meters (93 yards). The double-barreled approach gives astronomers the effective resolution of a single 85-meter telescope -- several times larger than any now planned.


"Nothing else in the world provides us with the types of measurements the Keck Interferometer does," said Wesley Traub of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "In effect, it's a zoom lens for the Keck telescopes."


The Keck Interferometer was developed by JPL and the W.M. Keck Observatory. It is managed by the W.M. Keck Observatory, which operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea on the island of Hawaii and is a scientific partnership of the California Institute of Technology in Pasadena, the University of California and NASA. NASA's Exoplanet Science Institute, also in Pasadena, manages time allocation on the telescope for NASA.


For more information, please visit: http://www.nasa.gov/topics/universe/features/keck-life-zone.html
Posted by Nelio Inacio at 7:06 PM 0 comments

The First of Many Asteroid Finds for WISE

The First of Many Asteroid Finds for WISE:

near-Earth asteroid discovered by NASA's Wide-Field Infrared Survey Explorer
The red dot at the center of this image is the first near-Earth asteroid discovered by NASA's Wide-Field Infrared Survey Explorer, or WISE Image credit: NASA/JPL-Caltech/UCLA

› Full image and caption


January 25, 2010

PASADENA, Calif. -- NASA's Wide-field Infrared Survey Explorer, or WISE, has spotted its first never-before-seen near-Earth asteroid, the first of hundreds it is expected to find during its mission to map the whole sky in infrared light. There is no danger of the newly discovered asteroid hitting Earth.


The near-Earth object, designated 2010 AB78, was discovered by WISE Jan. 12. The mission's sophisticated software picked out the moving object against a background of stationary stars. As WISE circled Earth, scanning the sky above, it observed the asteroid several times during a period of one-and-a-half days before the object moved beyond its view. Researchers then used the University of Hawaii's 2.2-meter (88-inch) visible-light telescope near the summit of Mauna Kea to follow up and confirm the discovery.


The asteroid is currently about 158 million kilometers (98 million miles) from Earth. It is estimated to be roughly 1 kilometer (0.6 miles) in diameter and circles the sun in an elliptical orbit tilted to the plane of our solar system. The object comes as close to the sun as Earth, but because of its tilted orbit, it will not pass very close to Earth for many centuries. This asteroid does not pose any foreseeable impact threat to Earth, but scientists will continue to monitor it.


Near-Earth objects are asteroids and comets with orbits that pass relatively close to Earth's path around the sun. In extremely rare cases of an impact, the objects may cause damage to Earth's surface. An asteroid about 10 kilometers (6 miles) wide is thought to have plunged into our planet 65 million years ago, triggering a global disaster and killing off the dinosaurs.


Additional asteroid and comet detections will continue to come from WISE. The observations will be automatically sent to the clearinghouse for solar system bodies, the Minor Planet Center in Cambridge, Mass., for comparison against the known catalog of solar system objects. A community of professional and amateur astronomers will provide follow-up observations, establishing firm orbits for the previously unseen objects.


"This is just the beginning," said Ned Wright, the mission's principal investigator from UCLA. "We've got a fire hose of data pouring down from space."


On Jan. 14, the WISE mission began its official survey of the entire sky in infrared light, one month after it rocketed into a polar orbit around Earth from Vandenberg Air Force Base in California. By casting a wide net, the mission will catch all sorts of cosmic objects, from asteroids in our own solar system to galaxies billions of light-years away. Its data will serve as a cosmic treasure map, pointing astronomers and telescopes, such as NASA's Spitzer Space Telescope and the upcoming James Webb Space Telescope, to the most interesting finds.


WISE is expected to find about 100,000 previously unknown asteroids in our main asteroid belt, a rocky ring of debris between the orbits of Mars and Jupiter. It will also spot hundreds of previously unseen near-Earth objects.


By observing infrared light, WISE will reveal the darkest members of the near-Earth object population -- those that don't reflect much visible light. The mission will contribute important information about asteroid and comet sizes. Visible-light estimates of an asteroid's size can be deceiving, because a small, light-colored space rock can look the same as a big, dark one. In infrared, however, a big dark rock will give off more of a thermal, or infrared glow, and reveal its true size. This size information will give researchers a better estimate of how often Earth can expect potentially devastating impacts.


"We are thrilled to have found our first new near-Earth object," said Amy Mainzer of NASA's Jet Propulsion Laboratory in Pasadena, Calif. Mainzer is the principal investigator of NEOWISE, a program to mine the collected WISE data for new solar system objects. "Many programs are searching for near-Earth objects using visible light, but some asteroids are dark, like pavement, and don't reflect a lot of sunlight. But like a parking lot, the dark objects heat up and emit infrared light that WISE can see."


"It is great to receive the first of many anticipated near-Earth object discoveries by the WISE system," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at JPL. "Analysis of the WISE data will go a long way toward understanding the true nature of this population."


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


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

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2010-028
Posted by Nelio Inacio at 7:06 PM 0 comments

NASA's WISE Mission Releases Medley of First Images

NASA's WISE Mission Releases Medley of First Images:

The Andromeda galaxy
The immense Andromeda galaxy, also known as Messier 31 or simply M31, is captured in full in this new image from NASA's Wide-field Infrared Survey Explorer, or WISE. Image credit: NASA/JPL-Caltech/UCLA


› Full image and caption


› More WISE first images


February 17, 2010

PASADENA, Calif. -- A diverse cast of cosmic characters is showcased in the first survey images NASA released Wednesday from its Wide-field Infrared Survey Explorer, or WISE.


Since WISE began its scan of the entire sky in infrared light on Jan. 14, the space telescope has beamed back more than a quarter of a million raw, infrared images. Four new, processed pictures illustrate a sampling of the mission's targets -- a wispy comet, a bursting star-forming cloud, the grand Andromeda galaxy and a faraway cluster of hundreds of galaxies. The images are online at http://www.jpl.nasa.gov/news/features.cfm?feature=2485.


"WISE has worked superbly," said Ed Weiler, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. "These first images are proving the spacecraft's secondary mission of helping to track asteroids, comets and other stellar objects will be just as critically important as its primary mission of surveying the entire sky in infrared."


One image shows the beauty of a comet called Siding Spring. As the comet parades toward the sun, it sheds dust that glows in infrared light visible to WISE. The comet's tail, which stretches about 10 million miles, looks like a streak of red paint. A bright star appears below it in blue.


"We've got a candy store of images coming down from space," said Edward (Ned) Wright of UCLA, the principal investigator for WISE. "Everyone has their favorite flavors, and we've got them all."


During its survey, the mission is expected to find perhaps dozens of comets, including some that ride along in orbits that take them somewhat close to Earth's path around the sun. WISE will help unravel clues locked inside comets about how our solar system came to be.


Another image shows a bright and choppy star-forming region called NGC 3603, lying 20,000 light-years away in the Carina spiral arm of our Milky Way galaxy. This star-forming factory is churning out batches of new stars, some of which are monstrously massive and hotter than the sun. The hot stars warm the surrounding dust clouds, causing them to glow at infrared wavelengths.


WISE will see hundreds of similar star-making regions in our galaxy, helping astronomers piece together a picture of how stars are born. The observations also provide an important link to understanding violent episodes of star formation in distant galaxies. Because NGC 3603 is much closer, astronomers use it as a lab to probe the same type of action that is taking place billions of light-years away.


Traveling farther out from our Milky Way, the third new image shows our nearest large neighbor, the Andromeda spiral galaxy. Andromeda is a bit bigger than our Milky Way and about 2.5 million light-years away. The new picture highlights WISE's wide field of view -- it covers an area larger than 100 full moons and even shows other smaller galaxies near Andromeda, all belonging to our "local group" of more than about 50 galaxies. WISE will capture the entire local group.


The fourth WISE picture is even farther out, in a region of hundreds of galaxies all bound together into one family. Called the Fornax cluster, these galaxies are 60 million light-years from Earth. The mission's infrared views reveal both stagnant and active galaxies, providing a census of data on an entire galactic community.


"All these pictures tell a story about our dusty origins and destiny," said Peter Eisenhardt, the WISE project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "WISE sees dusty comets and rocky asteroids tracing the formation and evolution of our solar system. We can map thousands of forming and dying solar systems across our entire galaxy. We can see patterns of star formation across other galaxies, and waves of star-bursting galaxies in clusters millions of light years away."


Other mission targets include comets, asteroids and cool stars called brown dwarfs. WISE discovered its first near-Earth asteroid on Jan. 12, and first comet on Jan. 22. The mission will scan the sky one-and-a-half times by October. At that point, the frozen coolant needed to chill its instruments will be depleted.


JPL manages WISE for NASA's Science Mission Directorate. The mission was competitively selected under NASA's Explorers Program, which NASA's Goddard Space Flight Center in Greenbelt, Md., manages. The Space Dynamics Laboratory in Logan, Utah, built the science instrument, and Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. For more information about WISE, visit http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://www.jpl.nasa.gov/wise.



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



2010-052
Posted by Nelio Inacio at 7:03 PM 0 comments

Cassini Data Show Ice and Rock Mixture Inside Titan

Cassini Data Show Ice and Rock Mixture Inside Titan:

This artist's illustration shows the likely interior structure of Saturn's moon Titan deduced from gravity field data collected by NASA's Cassini spacecraft.
This artist's illustration shows the likely interior structure of Saturn's moon Titan deduced from gravity field data collected by NASA's Cassini spacecraft. Image credit: NASA/JPL


› Full image and caption


March 11, 2010

PASADENA, Calif. -- By precisely tracking NASA's Cassini spacecraft on its low swoops over Saturn's moon Titan, scientists have determined the distribution of materials in the moon's interior. The subtle gravitational tugs they measured suggest the interior has been too cold and sluggish to split completely into separate layers of ice and rock.


The finding, to be published in the March 12 issue of the journal Science, shows how Titan evolved in a different fashion from inner planets such as Earth, or icy moons such as Jupiter's Ganymede, whose interiors have split into distinctive layers.


"These results are fundamental to understanding the history of moons of the outer solar system," said Cassini Project Scientist Bob Pappalardo, commenting on his colleagues' research. Pappalardo is with NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We can now better understand Titan's place among the range of icy satellites in our solar system."


Scientists have known that Titan, Saturn's largest moon, is about half ice and half rock, but they needed the gravity data to figure out how the materials were distributed. It turns out Titan's interior is a sorbet of ice studded with rocks that probably never heated up beyond a relatively lukewarm temperature. Only in the outermost 500 kilometers (300 miles) is Titan's ice devoid of any rock, while ice and rock are mixed to various extents at greater depth.


"To avoid separating the ice and the rock, you must avoid heating the ice too much," said David J. Stevenson, one of the paper's co-authors and a professor of planetary science at the California Institute of Technology in Pasadena. "This means that Titan was built rather slowly for a moon, in perhaps around a million years or so, back soon after the formation of the solar system."


This incomplete separation of ice and rock makes Titan less like Jupiter's moon Ganymede, where ice and rock have fully separated, and perhaps more like another Jovian moon, Callisto, which is believed to have a mixed ice and rock interior. Though the moons are all about the same size, they clearly have diverse histories.


The Cassini measurements help construct a gravity map, which may help explain why Titan has a stunted topography, since interior ice must be warm enough to flow slowly in response to the weight of heavy geologic structures, such as mountains.


Creating the gravity map required tracking minute changes in Cassini's speed along a line of sight from Earth to the spacecraft as it flew four close flybys of Titan between February 2006 and July 2008. The spacecraft took paths between about 1,300 to 1,900 kilometers (800 to 1,200 miles) above Titan.


"The ripples of Titan's gravity gently push and pull Cassini along its orbit as it passes by the moon and all these changes were accurately recorded by the ground antennas of the Deep Space Network within 5 thousandths of a millimeter per second [0.2 thousandths of an inch per second] even as the spacecraft was over a billion kilometers [more than 600 million miles] away," said Luciano Iess, a Cassini radio science team member at Sapienza University of Rome in Italy, and the paper's lead author. "It was a tricky experiment."


The results don't speak to whether Titan has an ocean beneath the surface, but scientists say this hypothesis is very plausible and they intend to keep investigating. Detecting tides induced by Saturn, a goal of the radio science team, would provide the clearest evidence for such a hidden water layer.


A Cassini interdisciplinary investigator, Jonathan Lunine, said of his colleagues' findings, "Additional flybys may tell us whether the crust is thick or thin today." Lunine is with the University of Rome, Tor Vergata, Italy, and the University of Arizona, Tucson. "With that information we may have a better understanding of how methane, the ephemeral working fluid of Titan's rivers, lakes and clouds, has been resupplied over geologic time. Like the history of water on Earth, this is fundamental to a deep picture of the nature of Titan through time."


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of Caltech, manages the project for NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed, developed and assembled at JPL. Cassini's radio science subsystem has been jointly developed by NASA and the Italian Space Agency (ASI).


More Cassini information is available, at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jia-rui.c.cook@jpl.nasa.gov


2010-084
Posted by Nelio Inacio at 7:02 PM 0 comments

See Spot on Jupiter. See Spot Glow.

See Spot on Jupiter. See Spot Glow.:

Jupiter's Great Red Spot
New thermal images from powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot. Image credit: NASA/JPL/ESO and NASA/ESA/GSFC


› Full image and caption


March 16, 2010

New thermal images from powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot, enabling scientists to make the first detailed interior weather map of the giant storm system.


The observations reveal that the reddest color of the Great Red Spot corresponds to a warm core within the otherwise cold storm system, and images show dark lanes at the edge of the storm where gases are descending into the deeper regions of the planet. These types of data, detailed in a paper appearing in the journal Icarus, give scientists a sense of the circulation patterns within the solar system's best-known storm system.


"This is our first detailed look inside the biggest storm of the solar system," said Glenn Orton, a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., who was one of the authors of the paper. "We once thought the Great Red Spot was a plain old oval without much structure, but these new results show that it is, in fact, extremely complicated."


Sky gazers have been observing the Great Red Spot in one form or another for hundreds of years, with continuous observations of its current shape dating back to the 19th century. The spot, which is a cold region averaging about 110 Kelvin (minus 260 degrees Fahrenheit) is so wide about three Earths could fit inside its boundaries.


The thermal images obtained by giant 8-meter (26-foot) telescopes used for this study -- the European Southern Observatory's Very Large Telescope in Chile, the Gemini Observatory telescope in Chile and the National Astronomical Observatory of Japan's Subaru telescope in Hawaii -- have provided an unprecedented level of resolution and extended the coverage provided by NASA's Galileo spacecraft in the late 1990s. Together with observations of the deep cloud structure by the 3-meter (10-foot) NASA Infrared Telescope Facility in Hawaii, the level of thermal detail observed from these giant observatories is comparable to visible-light images from NASA's Hubble Space Telescope for the first time.


One of the most intriguing findings shows the most intense orange-red central part of the spot is about 3 to 4 Kelvin (5 to 7 degrees Fahrenheit) warmer than the environment around it, said Leigh Fletcher, the lead author of the paper, who completed much of the research as a postdoctoral fellow at JPL and is currently a fellow at the University of Oxford in England. This temperature differential might not seem like a lot, but it is enough to allow the storm circulation, usually counter-clockwise, to shift to a weak clockwise circulation in the very middle of the storm. Not only that, but on other parts of Jupiter, the temperature change is enough to alter wind velocities and affect cloud patterns in the belts and zones.


"This is the first time we can say that there's an intimate link between environmental conditions -- temperature, winds, pressure and composition - and the actual color of the Great Red Spot," Fletcher said. "Although we can speculate, we still don't know for sure which chemicals or processes are causing that deep red color, but we do know now that it is related to changes in the environmental conditions right in the heart of the storm."


Unlocking the secrets of Jupiter's giant storm systems will be one of the targets for infrared spacecraft observations from future missions including NASA's Juno mission.


Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jia-rui.c.cook@jpl.nasa.gov



2010-086
Posted by Nelio Inacio at 7:02 PM 0 comments

Colony of Young Stars Shines in New Spitzer Image

Colony of Young Stars Shines in New Spitzer Image:

A colony of hot, young stars is stirring up the cosmic scene in this new picture from NASA's Spitzer Space Telescope
A colony of hot, young stars is stirring up the cosmic scene in this new picture from NASA's Spitzer Space Telescope. Image credit: NASA/JPL-Caltech

› Full image and caption


April 01, 2010

Astronomers have their eyes on a hot group of young stars, watching their every move like the paparazzi. A new infrared image from NASA's Spitzer Space Telescope shows the bustling star-making colony of the Orion nebula, situated in the hunter's sword of the famous constellation. Like Hollywood starlets, the cosmic orbs don't always shine their brightest, but vary over time. Spitzer is watching the stellar show, helping scientists learn more about why the stars change, and to what degree planet formation might play a role.


"This is an exploratory project. Nobody has done this before at a wavelength sensitive to the heat from dust circling around so many stars," said John Stauffer, the principal investigator of the research at NASA's Spitzer Science Center, located at the California Institute of Technology in Pasadena. "We are seeing a lot of variation, which may be a result of clumps or warped structures in the planet-forming disks."


The new image was taken after Spitzer ran out of its coolant in May 2009, beginning its extended "warm" mission. The coolant was needed to chill the instruments, but the two shortest-wavelength infrared channels still work normally at the new, warmer temperature of 30 Kelvin (minus 406 Fahrenheit). In this new phase of the mission, Spitzer is able to spend more time on projects that cover a lot of sky and require longer observation times.


One such project is the "Young Stellar Object Variability" program, in which Spitzer looks repeatedly at the same patch of the Orion nebula, monitoring the same set of about 1,500 variable stars over time. It has already taken about 80 pictures of the region over 40 days. A second set of observations will be made in fall 2010. The region's twinkling stars are about one million years old - this might invoke thoughts of wrinkle cream to a movie star, but in the cosmos, it is quite young. Our middle-aged sun is 4.6 billion years old.


Young stars are fickle, with brightness levels that change more than those of adult, sun-like stars. They also spin around faster. One reason for the ups and downs in brightness is the existence of cold spots on their surfaces. Cold spots are the opposite of "age spots" - the younger the star, the more it has. The cold spots come and go as a star whips around, changing the amount of light that reaches our telescopes.


Stellar brightness can also change due to hot spots, which are caused by gas accreting onto a young star from the material out of which it formed.


"In the 1950s and 60s, astronomers knew that younger stars varied, and they postulated this had something to do with the birthing process," said Stauffer. "Later, with improved technology, we could see a lot more and learned a great deal about the stars' spots."


Spitzer is particularly suited to study yet another reason why the stars are changing. The telescope's infrared sight can see the warm, dusty disks orbiting around them. These disks are where planets may eventually clump together and form. When the disks are young, they can have asymmetries, possibly caused by forming planets or gravitational disturbances from formed planets. As the skewed disks circle around a star, they block varying amounts of starlight.


By gathering more and more data on these varying disks, Stauffer and his team hope to learn more about how planets develop -- not exactly tabloid fodder, but an ongoing drama of one large, stellar family.


NASA's Jet Propulsion Laboratory in 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. Caltech manages JPL for NASA.


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

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2010-108
Posted by Nelio Inacio at 7:01 PM 0 comments

Cassini Doubleheader: Flying By Titan and Dione

Cassini Doubleheader: Flying By Titan and Dione:

Composite of Saturn's moons Titan and Dione
Composite of two images from NASA's Cassini spacecraft of Saturn's moons Titan (left) and Dione (right). Image credits: NASA/JPL/University of Arizona/Space Science Institute


› Full image and caption (Titan) | › Full image and caption (Dione)


April 02, 2010

In a special double flyby early next week, NASA's Cassini spacecraft will visit Saturn's moons Titan and Dione within a period of about a day and a half, with no maneuvers in between. A fortuitous cosmic alignment allows Cassini to attempt this doubleheader, and the interest in swinging by Dione influenced the design of its extended mission.


The Titan flyby, planned for Monday, April 5, will take Cassini to within about 7,500 kilometers (4,700 miles) of the moon's surface. The distance is relatively long as far as encounters go, but it works to the advantage of Cassini's imaging science subsystem. Cassini's cameras will be able to stare at Titan's haze-shrouded surface for a longer time and capture high-resolution pictures of the Belet and Senkyo areas, dark regions around the equator that ripple with sand dunes.


In the early morning of Wednesday, April 7 in UTC time zones, which is around 9 p.m. on Tuesday, April 6 in California, Cassini will make its closest approach to the medium-sized icy moon Dione. Cassini will plunge to within about 500 kilometers (300 miles) of Dione's surface.


This is only Cassini's second close encounter with Dione. The first flyby in October 2005, and findings from the Voyager spacecraft in the 1990s, hinted that the moon could be sending out a wisp of charged particles into the magnetic field around Saturn and potentially exhaling a diffuse plume that contributes material to one of the planet's rings. Like Enceladus, Saturn's more famous moon with a plume, Dione features bright, fresh fractures. But if there were a plume on Dione, it would certainly be subtler and produce less material.


Cassini plans to use its magnetometer and fields and particles instruments to see if it can find evidence of activity at Dione. Thermal mapping by the composite infrared spectrometer will also help in that search. In addition, the visual and infrared mapping spectrometer will examine dark material found on Dione. Scientists would like to understand the source of this dark material.


Cassini has made three previous double flybys and another two are planned in the years ahead. The mission is nearing the end of its first extension, known as the Equinox mission. It will begin its second mission extension, known as the Solstice Mission, in October 2010.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed, developed and assembled at JPL.


More information about the Titan flyby, dubbed "T67," is available at:

http://saturn.jpl.nasa.gov/mission/flybys/titan20100405/ .


More information about the Dione flyby, dubbed "D2," is available at:

http://saturn.jpl.nasa.gov/mission/flybys/dione20100407/

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jia-rui.c.cook@jpl.nasa.gov



2010-110
Posted by Nelio Inacio at 7:01 PM 0 comments

Asteroid to Fly by Within Moon's Orbit Thursday

Asteroid to Fly by Within Moon's Orbit Thursday:

Orbit of asteroid 2010 GA6
Orbit of asteroid 2010 GA6. Image credit: NASA/JPL



April 06, 2010

Updated April 08, 2010


With additional observations coming in, scientists at NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif. have been able to further refine the trajectory estimate for the orbit of asteroid 2010 GA6. This latest trajectory indicates that the closest approach for asteroid 2010 GA6 will be just slightly beyond the moon's orbit, about 434,000 kilometers (270,000 miles) from Earth. The time of closest approach will be 7:06 p.m. Pacific Daylight Time on April 8 (2:06 U.T.C. on April 9).

A newly discovered asteroid, 2010 GA6, will safely fly by Earth this Thursday at 4:06 p.m. Pacific (23:06 U.T.C.). At time of closest approach 2010 GA6 will be about 359,000 kilometers (223,000 miles) away from Earth - about 9/10ths the distance to the moon. The asteroid, approximately 22 meters (71 feet) wide, was discovered by the Catalina Sky Survey, Tucson, Az.


"Fly bys of near-Earth objects within the moon's orbit occur every few weeks," said Don Yeomans of NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif.


NASA detects and tracks asteroids and comets passing close to Earth using both ground and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them and plots their orbits to determine if any could be potentially hazardous to our planet.


JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Cornell University, Ithaca, N.Y., operates the Arecibo Observatory under a cooperative agreement with the National Science Foundation in Arlington, Va.


For more information about asteroids and near-Earth objects, visit: http://www.jpl.nasa.gov/asteroidwatch


DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


2010-115
Posted by Nelio Inacio at 7:00 PM 0 comments

Hiding Out Behind the Milky Way

Hiding Out Behind the Milky Way:

IC 342 galaxy
A leggy cosmic creature comes out of hiding in this new infrared view from NASA's Wide-field Infrared Survey Explorer, or WISE. Image credit: NASA/JPL-Caltech/UCLA


› Full image and caption


April 07, 2010

A leggy cosmic creature comes out of hiding in this new infrared view from NASA's Wide-field Infrared Survey Explorer, or WISE. The spiral beauty, called IC 342 and sometimes the "hidden galaxy," is shrouded behind our own galaxy, the Milky Way. Stargazers and professional astronomers have a hard time seeing the galaxy through the Milky Way's bright band of stars, dust and gas. WISE's infrared vision cuts through this veil, offering a crisp view.


In a spiral galaxy like IC 342, dust and gas are concentrated in the arms. The denser pockets of gas trigger the formation of new stars, as represented here in green and yellow. The core, shown in red, is also bursting with young stars, which are heating up dust. Stars that appear blue reside within our Milky Way, between us and IC 342.


This galaxy has been of great interest to astronomers because it is relatively close. However, determining its distance from Earth has proven difficult due to the intervening Milky Way. Astronomer Edwin Hubble first thought the galaxy might belong to our own Local Group of galaxies, but current estimates now place it farther away, at about 6.6 to 11 million light-years.


This image was made from observations by all four infrared detectors aboard WISE. Blue and cyan represent infrared light at wavelengths of 3.4 and 4.6 microns, which is primarily light from stars. Green and red represent light at 12 and 22 microns, which is primarily emission from warm dust.


Image credit: NASA/JPL-Caltech/UCLA


Whitney Clavin

(818) 354-4673

Whitney.clavin@jpl.nasa.gov



2010-116
Posted by Nelio Inacio at 7:00 PM 0 comments

Cassini Double Play: Enceladus and Titan

Cassini Double Play: Enceladus and Titan:

Saturn's moon Enceladus (left) and Titan (right)
On the left, Saturn's moon Enceladus is backlit by the sun, showing the fountain-like sources of the fine spray of material that towers over the south polar region. On the right, is a composite image of Titan. Image credit: NASA/JPL/SSI and NASA/JPL/University of Arizona


› Larger image


May 17, 2010

About a month and a half after its last double flyby, NASA's Cassini spacecraft will be turning another double play this week, visiting the geyser moon Enceladus and the hazy moon Titan. The alignment of the moons means that Cassini can catch glimpses of these two contrasting worlds within less than 48 hours, with no maneuver in between.


Cassini will make its closest approach to Enceladus late at night on May 17 Pacific time, which is in the early hours of May 18 UTC. The spacecraft will pass within about 435 kilometers (270 miles) of the moon's surface.


The main scientific goal at Enceladus will be to watch the sun play peekaboo behind the water-rich plume emanating from the moon's south polar region. Scientists using the ultraviolet imaging spectrograph will be able to use the flickering light to measure whether there is molecular nitrogen in the plume. Ammonia has already been detected in the plume and scientists know heat can decompose ammonia into nitrogen molecules. Determining the amount of molecular nitrogen in the plume will give scientists clues about thermal processing in the moon's interior.


The second of Cassini's two flybys is an encounter with Titan. The closest approach will take place in the late evening May 19 Pacific time, which is in the early hours of May 20 UTC. The spacecraft will fly to within 1,400 kilometers (750 miles) of the surface.


Cassini will primarily be doing radio science during this pass to detect the subtle variations in the gravitational tug on the spacecraft by Titan, which is 25 percent larger in volume than the planet Mercury. Analyzing the data will help scientists learn whether Titan has a liquid ocean under its surface and get a better picture of its internal structure. The composite infrared spectrometer will also get its southernmost pass for thermal data to fill out its temperature map of the smoggy moon.


Cassini has made four previous double flybys and one more is planned in the years ahead.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed, developed and assembled at JPL.


More information on the Enceladus flyby, dubbed "E10," is available at: http://saturn.jpl.nasa.gov/mission/flybys/enceladus20100518/


More information on the Titan flyby, dubbed "T68," is available at: http://saturn.jpl.nasa.gov/mission/flybys/titan20100520/


Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jia-rui.c.cook@jpl.nasa.gov



2010-164
Posted by Nelio Inacio at 6:59 PM 0 comments

Saturday, August 2, 2014

Cassini Double Play: Enceladus and Titan

Cassini Double Play: Enceladus and Titan:

Saturn's moon Enceladus (left) and Titan (right)
On the left, Saturn's moon Enceladus is backlit by the sun, showing the fountain-like sources of the fine spray of material that towers over the south polar region. On the right, is a composite image of Titan. Image credit: NASA/JPL/SSI and NASA/JPL/University of Arizona


› Larger image


May 17, 2010

About a month and a half after its last double flyby, NASA's Cassini spacecraft will be turning another double play this week, visiting the geyser moon Enceladus and the hazy moon Titan. The alignment of the moons means that Cassini can catch glimpses of these two contrasting worlds within less than 48 hours, with no maneuver in between.


Cassini will make its closest approach to Enceladus late at night on May 17 Pacific time, which is in the early hours of May 18 UTC. The spacecraft will pass within about 435 kilometers (270 miles) of the moon's surface.


The main scientific goal at Enceladus will be to watch the sun play peekaboo behind the water-rich plume emanating from the moon's south polar region. Scientists using the ultraviolet imaging spectrograph will be able to use the flickering light to measure whether there is molecular nitrogen in the plume. Ammonia has already been detected in the plume and scientists know heat can decompose ammonia into nitrogen molecules. Determining the amount of molecular nitrogen in the plume will give scientists clues about thermal processing in the moon's interior.


The second of Cassini's two flybys is an encounter with Titan. The closest approach will take place in the late evening May 19 Pacific time, which is in the early hours of May 20 UTC. The spacecraft will fly to within 1,400 kilometers (750 miles) of the surface.


Cassini will primarily be doing radio science during this pass to detect the subtle variations in the gravitational tug on the spacecraft by Titan, which is 25 percent larger in volume than the planet Mercury. Analyzing the data will help scientists learn whether Titan has a liquid ocean under its surface and get a better picture of its internal structure. The composite infrared spectrometer will also get its southernmost pass for thermal data to fill out its temperature map of the smoggy moon.


Cassini has made four previous double flybys and one more is planned in the years ahead.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed, developed and assembled at JPL.


More information on the Enceladus flyby, dubbed "E10," is available at: http://saturn.jpl.nasa.gov/mission/flybys/enceladus20100518/


More information on the Titan flyby, dubbed "T68," is available at: http://saturn.jpl.nasa.gov/mission/flybys/titan20100520/


Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jia-rui.c.cook@jpl.nasa.gov



2010-164
Posted by Nelio Inacio at 6:53 AM 0 comments

WISE Telescope has Heart and Soul

WISE Telescope has Heart and Soul:

Heart and Soul nebulae
The Heart and Soul nebulae are seen in this infrared mosaic from NASA's Wide-field Infrared Survey Explorer, or WISE. Image credit: NASA/JPL-Caltech/UCLA › Full image and caption


May 24, 2010

PASADENA, Calif. -- NASA's Wide-field Infrared Survey Explorer, or WISE, has captured a huge mosaic of two bubbling clouds in space, known as the Heart and Soul nebulae. The space telescope, which has completed about three-fourths of its infrared survey of the entire sky, has already captured nearly one million frames like the ones making up this newly released mosaic.


"This new image demonstrates the power of WISE to capture vast regions," said Ned Wright, the mission's principal investigator at UCLA, who presented the new picture today at the American Astronomical Society meeting in Miami. "We're looking north, south, east and west to map the whole sky."


The picture is online at http://www.nasa.gov/mission_pages/WISE/news/wise20100524.html .


The Heart nebula is named after its resemblance to a human heart; the nearby Soul nebula happens to resemble a heart too, but only the symbolic kind with two lobes. The nebulae, which lie about 6,000 light-years away in the constellation Cassiopeia, are both massive star-making factories, marked by giant bubbles blown into surrounding dust by radiation and winds from the stars. The infrared vision of WISE allows it to see into the cooler and dustier crevices of clouds like these, where gas and dust are just beginning to collect into new stars.


The new image was captured as WISE circled over Earth's poles, scanning strips of the sky. It is stitched together from 1,147 frames, taken with a total exposure time of three-and-a-half hours.


The mission will complete its first map of the sky in July 2010. It will then spend the next three months surveying much of the sky a second time, before the solid-hydrogen coolant needed to chill its infrared detectors runs dry. The first installment of the public WISE catalog will be released in summer 2011.


About 960,000 WISE images have been beamed down from space to date. Some show ethereal star-forming clouds, while others reveal the ancient light of very remote, powerful galaxies. And many are speckled with little dots that are asteroids in our solar system. So far, the mission has observed more than 60,000 asteroids, most of which lie in the main belt, orbiting between Mars and Jupiter. About 11,000 of these objects are newly discovered, and about 50 of them belong to a class of near-Earth objects, which have paths that take them within about 48 million kilometers (30 million miles) of Earth’s orbit.


One goal of the WISE mission is to study asteroids throughout our solar system and to find out more about how they vary in size and composition. Infrared helps with this task because it can get better size measurements of the space rocks than visible light.


"Infrared will help us understand more about the sizes, properties and origins of asteroids near and far," said Amy Mainzer, the principal investigator of NEOWISE, a program to study and catalog asteroids seen by WISE (the acronym comes from combining near-Earth object, or NEO, with WISE).


WISE will also study the Trojans, asteroids that run along with Jupiter in its orbit around the sun in two packs -- one in front of and one behind the gas giant. It has seen more than 800 of these objects, and by the end of the mission, should have observed about half of all 4,500 known Trojans. The results will address dueling theories about how the outer planets evolved.


"WISE is the first survey capable of observing the two clouds in a uniform way, and this will provide valuable insight into the early solar system," said astronomer Tommy Grav of Johns Hopkins University, Baltimore, Md., who presented the information today at the astronomy meeting.


Comets have also made their way into WISE images, with more than 72 observed so far, about a dozen of them new. WISE is taking a census of the types of orbits comets ride in. The data will help explain what kicks comets out of their original, more distant orbits and in toward the sun.


JPL manages WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu .



Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov

2010-174
Posted by Nelio Inacio at 6:53 AM 0 comments

Next Stop, Titan: Looking at the Land o' Lakes

Next Stop, Titan: Looking at the Land o' Lakes:

Artist's concept of Cassini's June 4, 2010, flyby of Saturn's moon Titan
Artist's concept of Cassini's June 4, 2010, flyby of Saturn's moon Titan. Image credit: NASA/JPL


› Larger view


June 03, 2010

NASA's Cassini spacecraft will be eyeing the north polar region of Saturn's moon Titan this weekend, scanning the moon's land o' lakes.


At closest approach on early morning Saturday, June 5 UTC, which is Friday afternoon, June 4 Pacific time, Cassini will glide to within about 2,000 kilometers (1,300 miles) of the Titan surface.


Cassini will make infrared scans of the north polar region, which was in darkness for the first several years of Cassini's tour around the Saturn system. The lighting has improved as northern spring has started to dawn over the area.


The visual and infrared spectrometer will be prime during closest approach, but the imaging science subsystem cameras will also be taking pictures. Among the scientific bounties, Cassini team members are hoping to get another good look at Kraken Mare, the largest lake on Titan, which covers a greater area than the Caspian Sea on Earth.


Although this latest flyby is dubbed "T69," planning changes early in the orbital tour made this the 70th targeted flyby of Titan.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jia-rui.c.cook@jpl.nasa.gov


2010-191
Posted by Nelio Inacio at 6:52 AM 0 comments

NASA Demonstrates Tsunami Prediction System

NASA Demonstrates Tsunami Prediction System:

Graphs showing Tsunami prediction system
Figure (a): NASA's Global Differential GPS (GDGPS) network measured the ground displacement caused by the magnitude 8.8 Chile earthquake on February 27, 2010, in real time at its station in Santiago, Chile. Figure (b): The coastal GPS data were used to calculate the tsunami source energy and drive the tsunami prediction model. Figure (c): The NASA/French Space AgencyJason-1 and Ocean Surface Topography Mission/Jason-2 satellites were used to confirm the tsunami amplitude prediction of the GPS-based model prediction. Image credits: NASA/JPL-Caltech


› Larger image


June 14, 2010

PASADENA, Calif. – A NASA-led research team has successfully demonstrated for the first time elements of a prototype tsunami prediction system that quickly and accurately assesses large earthquakes and estimates the size of resulting tsunamis.


After the magnitude 8.8 Chilean earthquake on Feb. 27, a team led by Y. Tony Song of NASA's Jet Propulsion Laboratory in Pasadena, Calif., used real-time data from the agency's Global Differential GPS (GDGPS) network to successfully predict the size of the resulting tsunami. The network, managed by JPL, combines global and regional real-time data from hundreds of GPS sites and estimates their positions every second. It can detect ground motions as small as a few centimeters.


"This successful test demonstrates that coastal GPS systems can effectively be used to predict the size of tsunamis," said Song. "This could allow responsible agencies to issue better warnings that can save lives and reduce false alarms that can unnecessarily disturb the lives of coastal residents."


Song's team concluded that the Chilean earthquake, the fifth largest ever recorded by instruments, would generate a moderate, or local, tsunami unlikely to cause significant destruction in the Pacific. The tsunami's effect was relatively small outside of Chile.


Song's GPS-based prediction was later confirmed using sea surface height measurements from the joint NASA/French Space Agency Jason-1 and Jason-2 altimetry satellites. This work was partially carried out by researchers at Ohio State University, Columbus.


"The value of coordinated real-time observations from precision GPS, satellite altimetry and advanced Earth models has been demonstrated," said John LaBrecque, manager of the Solid Earth and Natural Hazards program in the Earth Science Division of NASA's Science Mission Directorate in Washington.


Song's prediction method, published in 2007, estimates the energy an undersea earthquake transfers to the ocean to generate a tsunami. It relies on data from coastal GPS stations near an epicenter, along with information about the local continental slope. The continental slope is the descent of the ocean floor from the edge of the continental shelf to the ocean bottom.


Conventional tsunami warning systems rely on estimates of an earthquake's location, depth and magnitude to determine whether a large tsunami may be generated. However, history has shown earthquake magnitude is not a reliable indicator of tsunami size. Previous tsunami models presume a tsunami's power is determined by how much the seafloor is displaced vertically. Song's theory says horizontal motions of a faulting continental slope also contribute to a tsunami's power by transferring kinetic energy to the ocean.


The theory is further substantiated in a recently accepted research paper by Song and co-author Shin-Chan Han of NASA's Goddard Space Flight Center, Greenbelt, Md. That study used data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment (Grace) satellites to examine the 2004 Indian Ocean tsunami.


When the Feb. 27, 2010, earthquake struck, its ground motion was captured by the NASA GDGPS network's station in Santiago, Chile, about 235 kilometers (146 miles) from the earthquake's epicenter. These data were made available to Song within minutes of the earthquake, enabling him to derive the seafloor motions.


Based on these GPS data, Song calculated the tsunami's source energy, ranking it as moderate: a 4.8 on the system's 10-point scale (10 being most destructive). His conclusion was based on the fact that the ground motion detected by GPS indicated the slip of the fault transferred fairly minimal kinetic energy to the ocean.


"We were fortunate to have a station sufficiently close to the epicenter," said Yoaz Bar-Sever, JPL manager of the GDGPS system. "Broad international collaboration is required to densify the GPS tracking network so that it adequately covers all the fault zones that can give rise to large earthquakes around the world."


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


JPL is managed for NASA by the California Institute of Technology in Pasadena.


Alan Buis

818-354-0880

alan.buis@jpl.nasa.gov


2010-198
Posted by Nelio Inacio at 6:52 AM 0 comments
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