Sunday, July 20, 2014

NASA: Warm Rivers Play Role in Arctic Sea Ice Melt

NASA: Warm Rivers Play Role in Arctic Sea Ice Melt:

These images show sea surface temperatures of the Beaufort Sea where Canada's Mackenzie River discharges into the Arctic Ocean
These images show sea surface temperatures of the Beaufort Sea where Canada's Mackenzie River discharges into the Arctic Ocean, as measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra spacecraft. Image credit: NASA
› Larger image


March 05, 2014

The heat from warm river waters draining into the Arctic Ocean is contributing to the melting of Arctic sea ice each summer, a new NASA study finds.


A research team led by Son Nghiem of NASA's Jet Propulsion Laboratory in Pasadena, Calif., used satellite data to measure the surface temperature of the waters discharging from a Canadian river into the icy Beaufort Sea during the summer of 2012. They observed a sudden influx of warm river waters into the sea that rapidly warmed the surface layers of the ocean, enhancing the melting of sea ice. A paper describing the study is now published online in the journal Geophysical Research Letters.


This Arctic process contrasts starkly with those that occur in Antarctica, a frozen continent without any large rivers. The sea ice cover in the Southern Ocean surrounding Antarctica has been relatively stable, while Arctic sea ice has been declining rapidly over the past decade.


"River discharge is a key factor contributing to the high sensitivity of Arctic sea ice to climate change," said Nghiem. "We found that rivers are effective conveyers of heat across immense watersheds in the Northern Hemisphere. These watersheds undergo continental warming in summertime, unleashing an enormous amount of energy into the Arctic Ocean, and enhancing sea ice melt. You don't have this in Antarctica."


The team said the impacts of these warm river waters are increasing due to three factors. First, the overall volume of water discharged from rivers into the Arctic Ocean has increased. Second, rivers are getting warmer as their watersheds (drainage basins) heat up. And third, Arctic sea ice cover is becoming thinner and more fragmented, making it more vulnerable to rapid melt. In addition, as river heating contributes to earlier and greater loss of the Arctic's reflective sea ice cover in summer, the amount of solar heat absorbed into the ocean increases, causing even more sea ice to melt.


To demonstrate the extensive intrusion of warm Arctic river waters onto the Arctic sea surface, the team selected the Mackenzie River in western Canada. They chose the summer of 2012 because that year holds the record for the smallest total extent of sea ice measured across the Arctic in the more than 30 years that satellites have been making observations.


The researchers used data from satellite microwave sensors to examine the extent of sea ice in the study area from 1979 to 2012 and compared it to reports of Mackenzie River discharge. "Within this period, we found the record largest extent of open water in the Beaufort Sea occurred in 1998, which corresponds to the year of record high discharge from the river," noted co-author Ignatius Rigor of the University of Washington in Seattle.


The team analyzed data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra satellite to examine sea ice patterns and sea surface temperatures in the Beaufort Sea. They observed that on June 14, 2012, a stretch of landfast sea ice (sea ice that is stuck to the coastline) formed a barrier that held the river discharge close to its delta. After the river water broke through the ice barrier, sometime between June 14 and July 5, the team saw that the average surface temperature of the area of open water increased by 11.7 degrees Fahrenheit (6.5 degrees Celsius).


"When the Mackenzie River's water is held back behind the sea ice barrier, it accumulates and gets warmer later in the summer," said Nghiem. "So when it breaks through the barrier, it's like a strong surge, unleashing warmer waters into the Arctic Ocean that are very effective at melting sea ice. Without this ice barrier, the warm river waters would trickle out little by little, and there would be more time for the heat to dissipate to the atmosphere and to the cooler, deeper ocean."


"If you have an ice cube and drop a few water droplets on it, you're not going to see rapid melt," said co-author Dorothy Hall of NASA's Goddard Space Flight Center in Greenbelt, Md. "But if you pour a pitcher of warm water on the ice cube, it will appear to get smaller before your eyes. When warm river water surges onto sea ice, the ice melts rapidly."


Nghiem's team has linked this sea ice barrier, which forms recurrently and persistently in this area, to the physical characteristics of the shallow ocean continental shelf, and concludes the seafloor plays a role in delaying river discharge by holding the barrier in place along the shore of the Mackenzie delta.


The team estimated the heating power carried by the discharge of the 72 rivers in North America, Europe and Asia that flow into the Arctic Ocean. Based on published research of their average annual river discharge, and assuming an average summer river water temperature of around 41 degrees Fahrenheit (5 degrees Celsius), they calculated that the rivers are carrying as much heat into the Arctic Ocean each year as all of the electric energy used by the state of California in 50 years at today's consumption rate.


While MODIS can accurately measure sea surface temperature where rivers discharge warm waters into the Arctic Ocean, researchers currently lack reliable field measurements of subsurface temperatures across the mouths of river channels. Nghiem said more studies are needed to establish water temperature readings in Arctic-draining rivers to further understand their contribution to sea ice melt.


NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better understand how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.


For more information about NASA's Earth science activities in 2014, visit:

http://www.nasa.gov/earthrightnow .

For information on the latest NASA Earth science findings, visit:


http://www.nasa.gov/earth .

Written by Maria-Jose Vinas

NASA Earth Science News Team


Alan Buis

818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.buis@jpl.nasa.gov


2014-069
Posted by Nelio Inacio at 1:37 PM 0 comments

Mystery of Planet-forming Disks Explained by Magnetism

Mystery of Planet-forming Disks Explained by Magnetism:

Loops of Gas and Dust Rise from Planetary Disks
Magnetic loops carry gas and dust above disks of planet-forming material circling stars, as shown in this artist's conception. Image credit: NASA/JPL-Caltech
› Full image and caption


March 06, 2014

Astronomers say that magnetic storms in the gas orbiting young stars may explain a mystery that has persisted since before 2006.


Researchers using NASA's Spitzer Space Telescope to study developing stars have had a hard time figuring out why the stars give off more infrared light than expected. The planet-forming disks that circle the young stars are heated by starlight and glow with infrared light, but Spitzer detected additional infrared light coming from an unknown source.


A new theory, based on three-dimensional models of planet-forming disks, suggests the answer: Gas and dust suspended above the disks on gigantic magnetic loops like those seen on the sun absorb the starlight and glow with infrared light.


"If you could somehow stand on one of these planet-forming disks and look at the star in the center through the disk atmosphere, you would see what looks like a sunset," said Neal Turner of NASA's Jet Propulsion Laboratory, Pasadena, Calif.


The new models better describe how planet-forming material around stars is stirred up, making its way into future planets, asteroids and comets.


While the idea of magnetic atmospheres on planet-forming disks is not new, this is the first time they have been linked to the mystery of the observed excess infrared light. According to Turner and colleagues, the magnetic atmospheres are similar to what takes place on the surface of our sun, where moving magnetic field lines spur tremendous solar prominences to flare up in big loops.


Stars are born out of collapsing pockets in enormous clouds of gas and dust, rotating as they shrink down under the pull of gravity. As a star grows in size, more material rains down toward it from the cloud, and the rotation flattens this material out into a turbulent disk. Ultimately, planets clump together out of the disk material.


In the 1980s, the Infrared Astronomical Satellite mission, a joint project that included NASA, began finding more infrared light than expected around young stars. Using data from other telescopes, astronomers pieced together the presence of dusty disks of planet-forming material. But eventually it became clear the disks alone weren't enough to account for the extra infrared light -- especially in the case of stars a few times the mass of the sun.


One theory introduced the idea that instead of a disk, the stars were surrounded by a giant dusty halo, which intercepted the star's visible light and re-radiated it at infrared wavelengths. Then, recent observations from ground-based telescopes suggested that both a disk and a halo were needed. Finally, three-dimensional computer modeling of the turbulence in the disks showed the disks ought to have fuzzy surfaces, with layers of low-density gas supported by magnetic fields, similar to the way solar prominences are supported by the sun's magnetic field.


The new work brings these pieces together by calculating how the starlight falls across the disk and its fuzzy atmosphere. The result is that the atmosphere absorbs and re-radiates enough to account for all the extra infrared light.


"The starlight-intercepting material lies not in a halo, and not in a traditional disk either, but in a disk atmosphere supported by magnetic fields," said Turner. "Such magnetized atmospheres were predicted to form as the disk drives gas inward to crash onto the growing star."


Over the next few years, astronomers will further test these ideas about the structure of the disk atmospheres by using giant ground-based telescopes linked together as interferometers. An interferometer combines and processes data from multiple telescopes to show details finer than each telescope can see alone. Spectra of the turbulent gas in the disks will also come from NASA's SOFIA telescope, the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile, and from NASA's James Webb Space Telescope after its launch in 2018.


JPL 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. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colo. 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


2014-071
Posted by Nelio Inacio at 1:36 PM 0 comments

Cassini Nears 100th Titan Flyby with a Look Back

Cassini Nears 100th Titan Flyby with a Look Back:

This artist's concept shows a possible model of Titan's internal structure
This artist's concept shows a possible model of Titan's internal structure that incorporates data from NASA's Cassini spacecraft. Image credit: A. D. Fortes/UCL/STFC
› Full image and caption


March 05, 2014

Ten years ago, we knew Titan as a fuzzy orange ball about the size of Mercury. We knew it had a nitrogen atmosphere -- the only known world with a thick nitrogen atmosphere besides Earth. But what might lie beneath the hazy air was still just a guess.


On March 6, NASA's Cassini spacecraft will swoop down within 933 miles (1,500 kilometers) of Titan to conduct its 100th flyby of the Saturn moon. Each flyby gives us a little more knowledge of Titan and its striking similarities to our world. Even with its cold surface temperatures of minus 290 degrees Fahrenheit (94 kelvins), Titan is like early Earth in a deep freeze.


Since its 2004 arrival at Saturn, Cassini's radar instrument has identified remarkable surface features on Titan. The features include lakes and seas made of liquid methane and ethane, which are larger than North America's Great Lakes, and an extensive layer of liquid water deep beneath the surface. Organic molecules abound in Titan's atmosphere, formed from the breakup of methane by solar radiation.


A recent innovation was the discovery that radar could be used to determine the depth of a Titan sea. "It's something we didn't think we could do before," said Michael Malaska, an affiliate of the Cassini radar team at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The radar can measure the depth by receiving two different bounces: one from the surface and one from the bottom of the sea. This technique was used to determine that Ligeia Mare, the second largest sea on Titan, is about 160 meters [525 feet] deep. When coupled with some laboratory experiments, it gives us information about the composition of the liquid in Ligeia Mare, too."


As spring turns to summer in Titan's northern hemisphere for the first time since Cassini arrived at Saturn, scientists are looking forward to entering potentially the most exciting time for Titan weather - with waves and winds picking up. With increasing sunlight, the north polar lakes and seas can now be seen in near-infrared images, enabling scientists to learn more about their composition and giving them clues about the surrounding terrain.


"Methane is not only in the atmosphere, but probably in the crust," said Jonathan Lunine, a scientist on the Cassini mission at Cornell University, Ithaca, N.Y. "It's a hint there are organics not only in Titan's air and on the surface, but even in the deep interior, where liquid water exists as well. Organics are the building blocks of life, and if they are in contact with liquid water, there could be a chance of finding some form of life."


Linda Spilker, Cassini project scientist at JPL, speculated on the type of life that could exist. "The astrobiological potential for Titan is two-fold," she said. "Could a unique form of methane-based life exist in Titan's liquid lakes and seas? With a global ocean of liquid water beneath its icy crust, could life exist in Titan's subsurface ocean?"


Although the official Cassini mission name for this flyby is T-99, it is, in fact, the 100th targeted Titan flyby of the mission. Why the discrepancy? An extra flyby was inserted early in the mission, after the Titan flybys had been named.


For additional details on this 100th flyby, visit:

http://saturn.jpl.nasa.gov/mission/flybys/titan20140306/


For more information about Cassini, visit:

http://www.nasa.gov/cassini

and

http://saturn.jpl.nasa.gov


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, Pasadena, manages the mission for NASA's Science Mission Directorate in Washington.

Gay Hill

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-0344

gay.y.hill@jpl.nasa.gov


2014-070
Posted by Nelio Inacio at 1:36 PM 0 comments

NASA's WISE Survey Finds Thousands of New Stars, But No 'Planet X'

NASA's WISE Survey Finds Thousands of New Stars, But No 'Planet X':

A nearby star stands out in red in this image from the Second Generation Digitized Sky Survey.
A nearby star stands out in red in this image from the Second Generation Digitized Sky Survey. Image credit: DSS/NASA/JPL-Caltech
› Full image and caption


March 07, 2014

After searching hundreds of millions of objects across our sky, NASA's Wide-Field Infrared Survey Explorer (WISE) has turned up no evidence of the hypothesized celestial body in our solar system commonly dubbed "Planet X."


Researchers previously had theorized about the existence of this large, but unseen celestial body, suspected to lie somewhere beyond the orbit of Pluto. In addition to "Planet X," the body had garnered other nicknames, including "Nemesis" and "Tyche."


This recent study, which involved an examination of WISE data covering the entire sky in infrared light, found no object the size of Saturn or larger exists out to a distance of 10,000 astronomical units (au), and no object larger than Jupiter exists out to 26,000 au. One astronomical unit equals 93 million miles. Earth is 1 au, and Pluto about 40 au, from the sun.


"The outer solar system probably does not contain a large gas giant planet, or a small, companion star," said Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University, University Park, Pa., author of a paper in the Astrophysical Journal describing the results.


But searches of the WISE catalog are not coming up empty. A second study reveals several thousand new residents in our sun's "backyard," consisting of stars and cool bodies called brown dwarfs.


"Neighboring star systems that have been hiding in plain sight just jump out in the WISE data," said Ned Wright of the University of California, Los Angeles, the principal investigator of the mission.


The second WISE study, which concentrated on objects beyond our solar system, found 3,525 stars and brown dwarfs within 500 light-years of our sun.


"We're finding objects that were totally overlooked before," said Davy Kirkpatrick of NASA's Infrared and Processing Analysis Center at the California Institute of Technology, Pasadena, Calif. Kirkpatrick is lead author of the second paper, also in the Astrophysical Journal. Some of these 3,525 objects also were found in the Luhman study, which catalogued 762 objects.


The WISE mission operated from 2010 through early 2011, during which time it performed two full scans of the sky -- with essentially a six-month gap between scans. The survey captured images of nearly 750 million asteroids, stars and galaxies. In November 2013, NASA released data from the AllWISE program, which now enables astronomers to compare the two full-sky surveys to look for moving objects.


In general, the more an object in the WISE images appears to move over time, the closer it is. This visual clue is the same effect at work when one observes a plane flying low to the ground versus the same plane flying at higher altitude. Though traveling at the same speed, the plane at higher altitude will appear to be moving more slowly.


Searches of the WISE data catalog for these moving objects are uncovering some of the closest stars. The discoveries include a star located about 20 light-years away in the constellation Norma, and as reported last March, a pair of brown dwarfs only 6.5 light-years away -- making it the closest star system to be discovered in nearly a century.


Despite the large number of new solar neighbors found by WISE, "Planet X" did not show up. Previous speculations about this hypothesized body stemmed in part from geological studies that suggested a regular timing associated with mass extinctions on Earth. The idea was that a large planet or small star hidden in the farthest reaches of our solar system might periodically sweep through bands of outer comets, sending them flying toward our planet. The Planet X-based mass extinction theories were largely ruled out even prior to the new WISE study.


Other theories based on irregular comet orbits had also postulated a Planet X-type body. The new WISE study now argues against these theories as well.


Both of the WISE searches were able to find objects the other missed, suggesting many other celestial bodies likely await discovery in the WISE data.


"We think there are even more stars out there left to find with WISE. We don't know our own sun's backyard as well as you might think," said Wright.


WISE was put into hibernation upon completing its primary mission in 2011. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE will also characterize previously known asteroids and comets to better understand their sizes and compositions.


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

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-4673

whitney.clavin@jpl.nasa.gov


J.D. Harrington

Headquarters, Washington

202-358-5241

j.d.harrington@nasa.gov


2014-075
Posted by Nelio Inacio at 1:35 PM 0 comments

NASA Orbiter Safe After Unplanned Computer Swap

NASA Orbiter Safe After Unplanned Computer Swap:

Artist concept of Mars Reconnaissance Orbiter. Image credit: NASA/JPL
Artist concept of Mars Reconnaissance Orbiter. Image credit: NASA/JPL

› Full image and caption


March 11, 2014

NASA's long-lived Mars Reconnaissance Orbiter put itself into a precautionary safe standby mode March 9 after an unscheduled swap from one main computer to another. The mission's ground team has begun restoring the spacecraft to full operations.


"The spacecraft is healthy, in communication and fully powered," said Mars Reconnaissance Orbiter Project Manager Dan Johnston of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We have stepped up the communication data rate, and we plan to have the spacecraft back to full operations within a few days."


Mars Reconnaissance Orbiter's science observations and its relaying of communications from NASA's two active Mars rovers have been suspended. The rovers continue to use NASA's Mars Odyssey orbiter as a communications relay.


Entry into safe mode is the prescribed response by a spacecraft when it detects conditions outside the range of normal expectations. Mars Reconnaissance Orbiter has experienced unplanned computer swaps triggering safe-mode entry four times previously, most recently in November 2011. The root cause of the previous events has not been determined. The spacecraft has also experienced safe-mode entries that have not involved computer swaps.


Unlike any previous safe-mode entries experienced in this mission, the March 9 event included a swap to a redundant radio transponder on the orbiter. While the mission resumes operations with this transponder, engineers are investigating the status of the one that is now out of service.


NASA's Mars Reconnaissance Orbiter entered orbit around Mars eight years ago, on March 10, 2006. Since then, it has returned more data than all other past and current interplanetary missions combined. The mission met all its science goals in a two-year primary science phase. Three extensions, the latest beginning in 2012, have added to the science returns. The longevity of the mission has given researchers tools to study seasonal and longer-term changes on the Red Planet.


JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it. For more information about the Mars Reconnaissance Orbiter, visit http://www.nasa.gov/mro and http://mars.jpl.nasa.gov/mro/ .

Guy Webster 818-354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

guy.webster@jpl.nasa.gov


2013-078
Posted by Nelio Inacio at 1:35 PM 0 comments

Your 15 Minutes of 'Frame' - from NASA's Cassini

Your 15 Minutes of 'Frame' - from NASA's Cassini:

NASA's Cassini mission invites the public to transform images from the spacecraft for posting on an amateur image page
To help mark its 10th anniversary of exploring Saturn, its moons and rings, NASA's Cassini mission invites the public to transform images from the spacecraft for posting on an amateur image page. Image credit: NASA/JPL-Caltech


March 14, 2014

Arguably the most photogenic planet in the solar system, Saturn is the sixth planet from the sun and the second largest planet after Jupiter. With its luminous striped surface and stunning ring system, the planet is a wonder to view, especially from orbit, as NASA's Cassini spacecraft has demonstrated since arriving at the Saturn system in 2004.


Over the years, the Cassini mission website has been sharing raw, unprocessed versions of images sent to Earth by the spacecraft. On June 30 (July 1 EDT), Cassini will celebrate 10 years exploring Saturn, its rings and moons. To help mark 10 years in orbit, NASA's Jet Propulsion Laboratory in Pasadena, Calif., has created a special gallery on the Saturn website where members of the public can experience "15 minutes of frame" by submitting their own amateur images made up from image data brought back by Cassini.


With more than a half-dozen images and GIFs already live on the page, users are invited to visit Cassini's raw image database, dig through the treasure trove and create their own digital masterpiece and suggested caption. The submission process is as simple as filling out a form and uploading the image. Guidelines and further information can be found on the Cassini website.


Now that Cassini has completed its first decade of observations, mission planners are looking forward to the next phase, when the spacecrafts's instruments will return additional data and images. The mission will probe the densest part of the geysers spewing from Enceladus, and dive between Saturn and its innermost ring.


As part of the 10-year anniversary celebration, the Cassini team is releasing a video preview of the next four years of the mission:


http://youtu.be/fAQM9rfZq7w


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, 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 and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.


For more information about Cassini amateur images, visit:


http://saturn.jpl.nasa.gov/photos/amateurimages/


For more information about Cassini, visit:


http://saturn.jpl.nasa.gov/


and


http://www.nasa.gov/cassini

Jane Platt 818-354-0880

Jet Propulsion Laboratory, Pasadena, Calif.

jane.platt@jpl.nasa.gov


2014-081
Posted by Nelio Inacio at 1:34 PM 0 comments

NASA Technology Views Birth of the Universe

NASA Technology Views Birth of the Universe:

The BICEP2 telescope at the South Pole
The BICEP2 telescope at the South Pole used a specialized array of superconducting detectors to capture polarized light from billions of years ago. Image credit: NASA/JPL-Caltech
› Full image and caption


March 17, 2014

Astronomers are announcing today that they have acquired the first direct evidence that gravitational waves rippled through our infant universe during an explosive period of growth called inflation. This is the strongest confirmation yet of cosmic inflation theories, which say the universe expanded by 100 trillion trillion times, in less than the blink of an eye.

The findings were made with the help of NASA-developed detector technology on the BICEP2 telescope at the South Pole, in collaboration with the National Science Foundation.

"Operating the latest detectors in ground-based and balloon-borne experiments allows us to mature these technologies for space missions and, in the process, make discoveries about the universe," said Paul Hertz, NASA's Astrophysics Division director in Washington.

Our universe burst into existence in an event known as the Big Bang 13.8 billion years ago. Moments later, space itself ripped apart, expanding exponentially in an episode known as inflation. Telltale signs of this early chapter in our universe's history are imprinted in the skies, in a relic glow called the cosmic microwave background. Recently, this basic theory of the universe was again confirmed by the Planck satellite, a European Space Agency mission for which NASA provided detector and cooler technology.

But researchers had long sought more direct evidence for inflation in the form of gravitational waves, which squeeze and stretch space.

"Small, quantum fluctuations were amplified to enormous sizes by the inflationary expansion of the universe. We know this produces another type of waves called density waves, but we wanted to test if gravitational waves are also produced," said project co-leader Jamie Bock of NASA's Jet Propulsion Laboratory, Pasadena, Calif., which developed the BICEP2 detector technology. Bock has a joint appointment with the California Institute of Technology, also in Pasadena.

The gravitational waves produced a characteristic swirly pattern in polarized light, called "B-mode" polarization. Light can become polarized by scattering off surfaces, such as a car or pond. Polarized sunglasses reject polarized light to reduce glare. In the case of the cosmic microwave background, light scattered off particles called electrons to become slightly polarized.

The BICEP2 team took on the challenge to detect B-mode polarization by pulling together top experts in the field, developing revolutionary technology and traveling to the best observing site on Earth at the South Pole. The collaboration includes major contributions from Caltech; JPL; Stanford University, Stanford, Calif.; Harvard University, Cambridge, Mass.; and the University of Minnesota, Minneapolis.

As a result of experiments conducted since 2006, the team has been able to produce compelling evidence for the B-mode signal, and with it, the strongest support yet for cosmic inflation. The key to their success was the use of novel superconducting detectors. Superconductors are materials that, when chilled, allow electrical current to flow freely, with zero resistance.

"Our technology combines the properties of superconductivity with tiny structures that can only be seen with a microscope. These devices are manufactured using the same micro-machining process as the sensors in cellphones and Wii controllers," said Anthony Turner, who makes these devices using specialized fabrication equipment at JPL's Microdevices Laboratory.

The B-mode signal is extremely faint. In order to gain the necessary sensitivity to detect the polarization signal, Bock and Turner developed a unique array of multiple detectors, akin to the pixels in modern digital cameras but with the added ability to detect polarization. The whole detector system operates at a frosty 0.25 Kelvin, just 0.45 degrees Fahrenheit above the lowest temperature achievable, absolute zero.

"This extremely challenging measurement required an entirely new architecture," said Bock. "Our approach is like taking a camera and building it on a printed circuit board."

The BICEP2 experiment used 512 detectors, which sped up observations of the cosmic microwave background by 10 times over the team's previous measurements. Their new experiment, already making observations, uses 2,560 detectors.

These and future experiments not only help confirm that the universe inflated dramatically, but are providing theorists with the first clues about the exotic forces that drove space and time apart.

The results of this study have been submitted to the journal Nature.

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

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-4673

whitney.clavin@jpl.nasa.gov


2014-082
Posted by Nelio Inacio at 1:34 PM 0 comments

NASA Historic Earth Images Still Hold Research Value

NASA Historic Earth Images Still Hold Research Value:
This Seasat synthetic aperture radar image from Aug. 27, 1978
This Seasat synthetic aperture radar image from Aug. 27, 1978, shows the Massachusetts coast from Nantucket Island in the south past Cape Cod and Boston to Cape Ann in the north. Image Credit: Alaska Satellite Facility
› Full image and caption


March 18, 2014

NASA's Seasat satellite became history long ago, but it left a legacy of images of Earth's ocean, volcanoes, forests and other features that were made by the first synthetic aperture radar ever mounted on a satellite. Potential research uses for the recently released 35-year-old images are outlined in a paper published in the journal Eos today, March 18.

Seasat, which was managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., was the first satellite mission designed specifically to observe the ocean. Launched in 1978, it suffered a mission-ending power failure after 105 days of operation. But in that short time, Seasat collected more information about the ocean than had been acquired in the previous hundred years of shipboard research, said Benjamin Holt, a research scientist at JPL and coauthor of the Eos paper. The complete catalog of Seasat images has been processed digitally and is freely available from the Alaska Satellite Facility.

To access the Seasat images, visit:

https://www.asf.alaska.edu/seasat/ .

"There's still unique oceanographic data in these products that haven't been duplicated by more recent missions," said Holt. "We see different things in the Seasat images of the ocean currents than are seen by other satellites carrying synthetic aperture radar." This technology allows researchers to create very high-resolution images using complex information-processing techniques.

The 1978 data set also has value for climate studies of land cover simply because of its age. Holt noted that the images of Alaskan, Canadian and Norwegian glaciers are much earlier than any other satellite images that are currently available. This gives glaciologists an earlier baseline against which to measure the glaciers' rates of change.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's Earth science activities in 2014, visit:
http://www.nasa.gov/earthrightnow .

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.Buis@jpl.nasa.gov


Written by Carol Rasmussen

NASA Earth Science News Team


2014-085
Posted by Nelio Inacio at 1:33 PM 0 comments

NASA's Spitzer Telescope Brings 360-Degree View of Galaxy to Our Fingertips

NASA's Spitzer Telescope Brings 360-Degree View of Galaxy to Our Fingertips:

GLIMPSE the Galaxy All the Way Around
When you look up at the Milky Way on a clear, dark night, you'll see a band of bright stars arching overhead. This is the plane of our flat spiral galaxy, within which our solar system lies. NASA/JPL-Caltech/University of Wisconsin
› Full image and caption | Play video


March 20, 2014

Touring the Milky Way now is as easy as clicking a button with NASA's new zoomable, 360-degree mosaic presented Thursday at the TEDActive 2014 Conference in Vancouver, Canada.

The star-studded panorama of our galaxy is constructed from more than 2 million infrared snapshots taken over the past 10 years by NASA's Spitzer Space Telescope.

"If we actually printed this out, we'd need a billboard as big as the Rose Bowl Stadium to display it," said Robert Hurt, an imaging specialist at NASA's Spitzer Space Science Center in Pasadena, Calif. "Instead, we've created a digital viewer that anyone, even astronomers, can use."

The 20-gigapixel mosaic uses Microsoft's WorldWide Telescope visualization platform. It captures about three percent of our sky, but because it focuses on a band around Earth where the plane of the Milky Way lies, it shows more than half of all the galaxy's stars.

The image, derived primarily from the Galactic Legacy Mid-Plane Survey Extraordinaire project, or GLIMPSE, is online at:

http://www.spitzer.caltech.edu/glimpse360

Spitzer, launched into space in 2003 and has spent more than 10 years studying everything from asteroids in our solar system to the most remote galaxies at the edge of the observable universe. In this time, it has spent a total of 4,142 hours (172 days) taking pictures of the disk, or plane, of our Milky Way galaxy in infrared light. This is the first time those images have been stitched together into a single, expansive view.

Our galaxy is a flat spiral disk; our solar system sits in the outer one-third of the Milky Way, in one of its spiral arms. When we look toward the center of our galaxy, we see a crowded, dusty region jam-packed with stars. Visible-light telescopes cannot look as far into this region because the amount of dust increases with distance, blocking visible starlight. Infrared light, however, travels through the dust and allows Spitzer to view past the galaxy's center.

"Spitzer is helping us determine where the edge of the galaxy lies," said Ed Churchwell, co-leader of the GLIMPSE team at the University of Wisconsin-Madison. "We are mapping the placement of the spiral arms and tracing the shape of the galaxy."

Using GLIMPSE data, astronomers have created the most accurate map of the large central bar of stars that marks the center of the galaxy, revealing the Milky Way to be slightly larger than previously thought. GLIMPSE images have also shown a galaxy riddled with bubbles. These bubble structures are cavities around massive stars, which blast wind and radiation into their surroundings.

All together, the data allow scientists to build a more global model of stars, and star formation in the galaxy -- what some call the "pulse" of the Milky Way. Spitzer can see faint stars in the "backcountry" of our galaxy -- the outer, darker regions that went largely unexplored before.

"There are a whole lot more lower-mass stars seen now with Spitzer on a large scale, allowing for a grand study," said Barbara Whitney of the University of Wisconsin-Madison, co-leader of the GLIMPSE team. "Spitzer is sensitive enough to pick these up and light up the entire 'countryside' with star formation."

The Spitzer team previously released an image compilation showing 130 degrees of our galaxy, focused on its hub. The new 360-degree view will guide NASA's upcoming James Webb Space Telescope to the most interesting sites of star-formation, where it will make even more detailed infrared observations.

Some sections of the GLIMPSE mosaic include longer-wavelength data from NASA's Wide-field Infrared Survey Explorer, or WISE, which scanned the whole sky in infrared light.

The GLIMPSE data are also part of a citizen science project, where users can help catalog bubbles and other objects in our Milky Way galaxy. To participate, visit:

http://www.milkywayproject.org

More information about Spitzer is online at:

http://www.nasa.gov/spitzer

The Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer and WISE missions for NASA. The Spitzer Science Center is at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-4673

whitney.clavin@jpl.nasa.gov


J.D. Harrington

Headquarters, Washington

202-358-5241

j.d.harrington@nasa.gov


2014-088
Posted by Nelio Inacio at 1:31 PM 0 comments

Space Sunflower May Help Snap Pictures of Planets

Space Sunflower May Help Snap Pictures of Planets:

This animation shows the prototype starshade, a giant structure designed to block the glare of stars so that future space telescopes can take pictures of planets.
This animation shows the prototype starshade, a giant structure designed to block the glare of stars so that future space telescopes can take pictures of planets.
› Play video


March 20, 2014

A spacecraft that looks like a giant sunflower might one day be used to acquire images of Earth-like rocky planets around nearby stars. The prototype deployable structure, called a starshade, is being developed by NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The hunt is on for planets that resemble Earth in size, composition and temperature. Rocky planets with just the right temperature for liquid water -- not too hot, not too cold -- could be possible abodes for life outside our solar system. NASA's Kepler mission has discovered hundreds of planets orbiting other stars, called exoplanets, some of which are a bit larger than Earth and lie in this comfortable "Goldilocks" zone.

Researchers generally think it's only a matter of time before we find perfect twins of Earth. The next step would be to image and characterize their spectra, or chemical signatures, which provide clear clues about whether those worlds could support life. The starshade is designed to help take those pictures of planets by blocking out the overwhelmingly bright light of their stars. Simply put, the starshade is analogous to holding your hand up to the sun to block it while taking a picture of somebody.

The proposed starshade could launch together with a telescope. Once in space, it would separate from the rocket and telescope, unfurl its petals, then move into position to block the light of stars.

The project is led by Jeremy Kasdin, a professor at Princeton University, N.J., in conjunction with JPL and support from Northrop Grumman of Redondo Beach, Calif.

Kasdin gave a TED talk about the project on March 19. More information is at:

http://bit.ly/1nHgLhU

Read more about the Starshade at:

http://planetquest.jpl.nasa.gov/video/15

JPL manages NASA's Exoplanet Exploration program office.

Whitney Clavin

818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2014-089
Posted by Nelio Inacio at 1:31 PM 0 comments

NASA Hosts Deep Space Network Social Media Event

NASA Hosts Deep Space Network Social Media Event:

Beam Wave Guide antennas at Goldstone, known as the
Beam Wave Guide antennas at Goldstone, known as the "Beam Waveguide Cluster." Each antenna is 111.5-feet (34-m) in diameter. They're located in an area at Goldstone called "Apollo Valley." This photograph was taken on Jan. 11, 2012. Credit: NASA/JPL-Caltech
› Full image and caption


March 25, 2014

About 50 people from 11 U.S. states will attend a two-day NASA Social, to be held April 1 at the agency's Jet Propulsion Laboratory in Pasadena, Calif., and April 2 at NASA's Deep Space Network complex in Goldstone, Calif.

The attendees, who follow NASA and JPL on Twitter, Facebook, Google+ and other social networks, will be provided a unique, in-person experience, which they are encouraged to share with others through their favorite social networks. They were selected from nearly 500 people who registered online last month. Participants represent California, Florida, Illinois, Maryland, New Jersey, New York, Ohio, Rhode Island, Texas, Virginia and Washington.

On April 1 at JPL, attendees will be based inside the Space Flights Operations Facility, which is the mission control center of NASA's Deep Space Network. That's where engineers communicate with spacecraft across the solar system. Tour stops will include the Spacecraft Assembly Facility, where hardware for upcoming missions is under construction, and the Mars Yard, where engineering models of NASA's Curiosity rover are tested in a sandy, Mars-like environment.

On April 2, participants will attend the Deep Space Network's 50th anniversary celebration at the Goldstone Deep Space Communications Complex near Barstow in California's Mojave Desert. The tour will include Apollo Valley, site of the historic Apollo antenna; Mars Valley, home of the 70-meter Mars antenna; and the Spacecraft Operations Control Center.

NASA Television will broadcast a portion of the NASA Social on April 1 starting at 9:30 a.m. PDT (12:30 p.m. EDT) at: http://www.nasa.gov/ntv and http://www.ustream.tv/nasajpl2 .

To join and track the conversation online during the NASA Social, follow the hashtags #NASASocial and #DSN50.

More information about connecting and collaborating with NASA is at: http://www.nasa.gov/connect

More information about the Deep Space Network is at: http://deepspace.jpl.nasa.gov

The California Institute of Technology manages JPL for NASA.

Courtney O'Connor 818-354-2274

Jet Propulsion Laboratory, Pasadena, Calif.

oconnor@jpl.nasa.gov


John Yembrick/Jason Townsend 650-604-2065 / 202-358-0359

NASA Headquarters, Washington

john.yembrick@nasa.gov / jason.c.townsend@nasa.gov


2014-092
Posted by Nelio Inacio at 1:30 PM 0 comments

The Search for Seeds of Black Holes

The Search for Seeds of Black Holes:

Bulgeless Galaxy Hides Black Hole
The galaxy NGC 4395 is shown here in infrared light, captured by NASA's Spitzer Space Telescope. Image credit: NASA/JPL-Caltech
› Full image and caption


March 26, 2014

How do you grow a supermassive black hole that is a million to a billion times the mass of our sun? Astronomers do not know the answer, but a new study using data from NASA's Wide-field Infrared Survey Explorer, or WISE, has turned up what might be the cosmic seeds from which a black hole will sprout. The results are helping scientists piece together the evolution of supermassive black holes -- powerful objects that dominate the hearts of all galaxies.

Growing a black hole is not as easy as planting a seed in soil and adding water. The massive objects are dense collections of matter that are literally bottomless pits; anything that falls in will never come out. They come in a range of sizes. The smallest, only a few times greater in mass than our sun, form from exploding stars. The biggest of these dark beasts, billions of times the mass of our sun, grow together with their host galaxies over time, deep in the interiors. But how this process works is an ongoing mystery.

Researchers using WISE addressed this question by looking for black holes in smaller, "dwarf" galaxies. These galaxies have not undergone much change, so they are more pristine than their heavier counterparts. In some ways, they resemble the types of galaxies that might have existed when the universe was young, and thus they offer a glimpse into the nurseries of supermassive black holes.

In this new study, using data of the entire sky taken by WISE in infrared light, up to hundreds of dwarf galaxies have been discovered in which buried black holes may be lurking. Infrared light, the kind that WISE collects, can see through dust, unlike visible light, so it's better able to find the dusty, hidden black holes. The researchers found that the dwarf galaxies' black holes may be about 1,000 to 10,000 times the mass of our sun -- larger than expected for these small galaxies.

"Our findings suggest the original seeds of supermassive black holes are quite massive themselves," said Shobita Satyapal of George Mason University, Fairfax, Va. Satyapal is lead author of a paper published in the March issue of Astrophysical Journal.

Daniel Stern, an astronomer specializing in black holes at NASA's Jet Propulsion Laboratory, Pasadena, Calif., who was not a part of the new study, says the research demonstrates the power of an all-sky survey like WISE to find the rarest black holes. "Though it will take more research to confirm whether the dwarf galaxies are indeed dominated by actively feeding black holes, this is exactly what WISE was designed to do: find interesting objects that stand out from the pack."

The new observations argue against one popular theory of black hole growth, which holds that the objects bulk up in size through galaxy collisions. When our universe was young, galaxies were more likely to crash into others and merge. It is possible the galaxies' black holes merged too, accumulating more mass. In this scenario, supermassive black holes grow in size through a series of galaxy mergers.

The discovery of dwarf galaxy black holes that are bigger than expected suggests that galaxy mergers are not necessary to create big black holes. Dwarf galaxies don't have a history of galactic smash-ups, and yet their black holes are already relatively big.

Instead, supermassive black holes might form very early in the history of the universe. Or, they might grow harmoniously with their host galaxies, feeding off surrounding gas.

"We still don't know how the monstrous black holes that reside in galaxy centers formed," said Satyapal. "But finding big black holes in tiny galaxies shows us that big black holes must somehow have been created in the early universe, before galaxies collided with other galaxies."

Other authors of the study include: N.J. Secrest, W. McAlpine and J.L. Rosenberg of George Mason University; S.L. Ellison of the University of Victoria, Canada; and J. Fischer of the Naval Research Laboratory, Washington.

WISE was put into hibernation upon completing its primary mission in 2011. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE will also characterize previously known asteroids and comets to better understand their sizes and compositions.

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

More information on WISE and NEOWISE can be found online at:

http://www.nasa.gov/wise, http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2014-093
Posted by Nelio Inacio at 1:29 PM 0 comments

Satellite Shows High Productivity from U.S. Corn Belt

Satellite Shows High Productivity from U.S. Corn Belt:

The magnitude of fluorescence portrayed in this visualization
The magnitude of fluorescence portrayed in this visualization prompted researchers to take a closer look at the productivity of the U.S. Corn Belt. The glow represents fluorescence measured from land plants in early July, over a period from 2007 to 2011. Image credit:
NASA's Goddard Space Flight Center
› Larger image


March 31, 2014

Data from satellite sensors show that during the Northern Hemisphere's growing season, the Midwest region of the United States boasts more photosynthetic activity than any other spot on Earth, according to NASA and university scientists.

Healthy plants convert light to energy via photosynthesis, but chlorophyll also emits a fraction of absorbed light as a fluorescent glow that is invisible to the naked eye. The magnitude of the glow is an excellent indicator of the amount of photosynthesis, or gross productivity, of plants in a given region.

Research in 2013, led by Joanna Joiner of NASA's Goddard Space Flight Center in Greenbelt, Md., demonstrated that fluorescence from plants could be teased out from existing data from satellites that were designed and built for other purposes. The new research, led by Luis Guanter of the Freie Universität Berlin, used the data for the first time to estimate photosynthesis from agriculture. Results were published March 25 in the Proceedings of the National Academy of Sciences.

According to co-author Christian Frankenberg of NASA's Jet Propulsion Laboratory in Pasadena, Calif., "The paper shows that fluorescence is a much better proxy for agricultural productivity than anything we've had before. This can go a long way regarding monitoring -- and maybe even predicting -- regional crop yields."

Guanter, Joiner and Frankenberg launched their collaboration at a 2012 workshop, hosted by the Keck Institute for Space Studies at the California Institute of Technology (Caltech) in Pasadena, to explore measurements of photosynthesis from space. The team noticed that on an annual basis, the tropics are the most active in photosynthesis. But during the Northern Hemisphere's growing season, the U.S. Corn Belt "really stands out," Frankenberg said. "Areas all over the world are not as productive as this area."

The researchers set out to describe the phenomenon observed by carefully interpreting data from the Global Ozone Monitoring Experiment 2 (GOME-2) on Metop-A, a European meteorological satellite. Data showed that fluorescence from the U.S. Corn Belt peaks in July at levels 40 percent greater than those observed in the Amazon.

Comparison with ground-based measurements from carbon flux towers and yield statistics confirmed the results.

"The match between ground-based measurements and satellite measurements was a pleasant surprise," said Joiner, a co-author on the paper.

Ground-based measurements have a resolution of about 0.4 square mile (1 square kilometer), while the satellite measurements currently have a resolution of more than 1,158 square miles (3,000 square kilometers). The study confirms that even with coarse resolution, the satellite method could estimate the photosynthetic activity occurring inside plants at the molecular level for areas with relatively homogenous vegetation like the Corn Belt.

Challenges remain in estimating the productivity of fragmented agricultural areas not properly sampled by current space-borne instruments. That's where missions with better resolution could help, such as NASA's Orbiting Carbon Observatory-2 (OCO-2) -- a mission planned for launch in July 2014 that will also measure solar-induced fluorescence.

The research could also help scientists improve the computer models that simulate Earth's carbon cycle, as Guanter found a strong underestimation of crop photosynthesis in models. The analysis revealed that carbon cycle models -- which scientists use to understand how carbon cycles through the ocean, land and atmosphere over time -- underestimate the productivity of the U.S. Corn Belt by 40 to 60 percent.

Unlike most vegetation, food crops are managed to maximize productivity. They usually have access to abundant nutrients and are irrigated. The U.S. Corn Belt, for example, receives water from the Mississippi River. Accounting for the region's irrigation is currently a challenge for models, which is one reason why they underestimate agricultural productivity.

"If we don't take into account irrigation and other human influences in the agricultural areas, we're not going to correctly estimate the amount of carbon taken up by vegetation, particularly corn," Joiner said. "Corn plants are very productive in terms of assimilating carbon dioxide from the atmosphere. This needs to be accounted for going forward in trying to predict how much of the atmospheric carbon dioxide will be taken up by crops in a changing climate."

According to Frankenberg, the remote sensing-based techniques now available could be a powerful monitoring tool for food security, especially data from OCO-2 in combination with data from other upcoming satellites such as NASA's Soil Moisture Active Passive (SMAP), scheduled for launch later this year.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

Caltech manages the Jet Propulsion Laboratory for NASA.

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

Kathryn Hansen

NASA's Goddard Space Flight Center, Greenbelt, Md.

301-286-1046

kathryn.h.hansen@nasa.gov


Alan Buis
NASA's Jet Propulsion Laboratory, Pasadena, Calif.

818-354-0474

alan.buis@jpl.nasa.gov


Carsten Wette

Freie Universität Berlin

030-838-73189

carsten.wette@fu-berlin.de


2014-097
Posted by Nelio Inacio at 1:28 PM 0 comments

NASA Model Provides a 3-D Look at L.A.-area Quake

NASA Model Provides a 3-D Look at L.A.-area Quake:


JPL scientists modeled the March 28, 2014 magnitude 5.1 quake near Los Angeles based on USGS seismic data. This model image shows how the quake may appear to airborne radar, such as NASA's UAVSAR, which will survey the area soon. Blue shades indicate the greatest surface displacement. Credit: NASA/JPL-Caltech/USGS/Google Earth
› Larger image


March 31, 2014

On March 28, residents of Greater Los Angeles experienced the largest earthquake to strike the region since 2008. The magnitude 5.1 quake was centered near La Habra in northwestern Orange County about 21 miles (33 kilometers) east-southeast of Los Angeles, and was widely felt throughout Southern California. There have been hundreds of aftershocks, including one of magnitude 4.1.

Scientists at NASA's Jet Propulsion Laboratory, Pasadena, Calif., have developed a model of the earthquake, based on the distribution of aftershocks and other seismic information from the U.S. Geological Survey.

A new image based on the model shows what the earthquake may look like through the eyes of an interferometric synthetic aperture radar, such as NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR). JPL scientists plan to acquire UAVSAR data from the region of the March 28 quake, possibly as soon as this week, and process the data to validate and improve the results of their model.

The model image is online at:

http://www.jpl.nasa.gov/spaceimages/details.php?id=pia18041

The earthquake is believed to be associated with the Puente Hills Thrust fault, a blind thrust fault (meaning it does not break the earth surface) that zigzags from Orange County northwest through downtown Los Angeles. The same fault was responsible for the magnitude 5.9 Whittier Narrows earthquake on Oct. 1, 1987, which caused eight fatalities, injured several hundred and left about $360 million in property damage.

The NASA model is based on a fault estimated to be 5.6 miles (9 kilometers) long, 3.1 miles (5 kilometers) deep and 1.9 miles (3 kilometers) wide. The modeled fault segment dips upward through the ground at a 60-degree angle. The model estimated that in this earthquake, one side of the fault moved at a slanted angle horizontally and vertically 3.9 inches (10 centimeters) relative to the other side. The model also estimated the maximum displacement of Earth's surface from the quake at approximately 0.4 inch (1 centimeter), which is at the threshold of what is detectable with UAVSAR. The region of greatest ground displacement is indicated by the darker blue area located in the right center of the image.

In Nov. 2008, NASA JPL scientists began conducting a series of UAVSAR flights over regions of Northern and Southern California that are actively deforming and are marked by frequent earthquakes. About every six months, the scientists precisely repeat the same flight paths to produce images of ground deformation called interferograms. From these data, 3-D maps are being created for regions of interest, including the San Andreas and other California faults, extending from the Gulf of California in Mexico to Santa Rosa in the northern San Francisco Bay.

UAVSAR, which flies on a NASA C-20A aircraft from NASA's Armstrong Flight Research Center in California, measures ground deformation over large areas to a precision of 0.04 to 0.2 inches (0.1 to 0.5 centimeters).

By comparing the repeat-pass radar observations, scientists hope to measure any crustal deformations that may occur between observations, allowing them to "see" the amount of strain building up on fault lines, and giving them a clearer picture of which faults are active and at what rates they're moving, both before earthquakes and after them. The UAVSAR fault mapping project is designed to substantially improve knowledge of regional earthquake hazards in California. The 3-D UAVSAR data will allow scientists to bring entire faults into focus, allowing them to understand faults not just at their surfaces, but also at depth. When integrated into computer models, the data should give scientists a much clearer picture of California's complex fault systems.

The scientists are estimating the total displacement occurring in each region. As additional observations are collected, they expect to be able to determine how strain is partitioned between individual faults.

The UAVSAR flights serve as a baseline for pre-earthquake activity. As earthquakes occur during the course of this project, the team is measuring the deformation at the time of the earthquakes to determine the distribution of slip on the faults, and then monitoring longer-term motions after the earthquakes to learn more about fault zone properties.

Airborne UAVSAR mapping can allow a rapid response after an earthquake to determine what fault was the source and which parts of the fault slipped during the earthquake. Information about the earthquake source can be used to estimate what areas were most affected by an earthquake's shaking to guide rescue efforts and damage assessment.

The model was developed as part of NASA's QuakeSim project. The JPL-developed QuakeSim is a comprehensive, state-of-the-art software tool for simulating and understanding earthquake fault processes and improving earthquake forecasting. Initiated in 2002, QuakeSim uses NASA remote sensing and other earthquake-related data to simulate and model the behavior of faults in 3-D both individually and as part of complex, interacting systems. This provides long-term histories of fault behavior that can be used for statistical evaluation. QuakeSim also is used to identify regions of increased earthquake probabilities, called hotspots.

NASA's Earthquake Data Enhanced Cyber-Infrastructure for Disaster Evaluation and Response (E-DECIDER) project, which provides tools for earthquake disaster management and response using remote sensing data and NASA earthquake modeling software, published the model results, along with automatically generated deformation models and aftershock forecasts on a La Habra earthquake event page: http://e-decider.org/content/la-habra-earthquake-march-2014


For more on QuakeSim, visit: http://www.quakesim.org

For more information about UAVSAR, visit:

http://uavsar.jpl.nasa.gov/

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.buis@jpl.nasa.gov


2014-098
Posted by Nelio Inacio at 1:28 PM 0 comments

NASA Space Assets Detect Ocean inside Saturn Moon

NASA Space Assets Detect Ocean inside Saturn Moon:

Ocean Inside Saturn's Moon Enceladus
Gravity measurements by NASA's Cassini spacecraft and Deep Space Network suggest that Saturn's moon Enceladus, which has jets of water vapor and ice gushing from its south pole, also harbors a large interior ocean beneath an ice shell, as this illustration depicts. Image credit: NASA/JPL-Caltech
› Full image and caption


April 03, 2014

NASA's Cassini spacecraft and Deep Space Network have uncovered evidence Saturn's moon Enceladus harbors a large underground ocean of liquid water, furthering scientific interest in the moon as a potential home to extraterrestrial microbes.

Researchers theorized the presence of an interior reservoir of water in 2005 when Cassini discovered water vapor and ice spewing from vents near the moon's south pole. The new data provide the first geophysical measurements of the internal structure of Enceladus, consistent with the existence of a hidden ocean inside the moon. Findings from the gravity measurements are in the Friday, April 4 edition of the journal Science.

"The way we deduce gravity variations is a concept in physics called the Doppler Effect, the same principle used with a speed-measuring radar gun," said Sami Asmar of NASA's Jet Propulsion Laboratory in Pasadena, Calif., a coauthor of the paper. "As the spacecraft flies by Enceladus, its velocity is perturbed by an amount that depends on variations in the gravity field that we're trying to measure. We see the change in velocity as a change in radio frequency, received at our ground stations here all the way across the solar system."

The gravity measurements suggest a large, possibly regional, ocean about 6 miles (10 kilometers) deep, beneath an ice shell about 19 to 25 miles (30 to 40 kilometers) thick. The subsurface ocean evidence supports the inclusion of Enceladus among the most likely places in our solar system to host microbial life. Before Cassini reached Saturn in July 2004, no version of that short list included this icy moon, barely 300 miles (500 kilometers) in diameter.

"This then provides one possible story to explain why water is gushing out of these fractures we see at the south pole," said David Stevenson of the California Institute of Technology, Pasadena, one of the paper's co-authors.

Cassini has flown near Enceladus 19 times. Three flybys, from 2010 to 2012, yielded precise trajectory measurements. The gravitational tug of a planetary body, such as Enceladus, alters a spacecraft's flight path. Variations in the gravity field, such as those caused by mountains on the surface or differences in underground composition, can be detected as changes in the spacecraft's velocity, measured from Earth.

The technique of analyzing a radio signal between Cassini and the Deep Space Network can detect changes in velocity as small as less than one foot per hour (90 microns per second). With this precision, the flyby data yielded evidence of a zone inside the southern end of the moon with higher density than other portions of the interior.

The south pole area has a surface depression that causes a dip in the local tug of gravity. However, the magnitude of the dip is less than expected given the size of the depression, leading researchers to conclude the depression's effect is partially offset by a high-density feature in the region, beneath the surface.

"The Cassini gravity measurements show a negative gravity anomaly at the south pole that however is not as large as expected from the deep depression detected by the onboard camera," said the paper's lead author, Luciano Iess of Sapienza University of Rome. "Hence the conclusion that there must be a denser material at depth that compensates the missing mass: very likely liquid water, which is seven percent denser than ice. The magnitude of the anomaly gave us the size of the water reservoir."

There is no certainty the subsurface ocean supplies the water plume spraying out of surface fractures near the south pole of Enceladus, however, scientists reason it is a real possibility. The fractures may lead down to a part of the moon that is tidally heated by the moon's repeated flexing, as it follows an eccentric orbit around Saturn.

Much of the excitement about the Cassini mission's discovery of the Enceladus water plume stems from the possibility that it originates from a wet environment that could be a favorable environment for microbial life.

"Material from Enceladus' south polar jets contains salty water and organic molecules, the basic chemical ingredients for life," said Linda Spilker, Cassini's project scientist at JPL. "Their discovery expanded our view of the 'habitable zone' within our solar system and in planetary systems of other stars. This new validation that an ocean of water underlies the jets furthers understanding about this intriguing environment."

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 in Washington. For more information about Cassini, visit:

http://www.nasa.gov/cassini

and

http://saturn.jpl.nasa.gov

Jane Platt
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0880
jane.platt@jpl.nasa.gov

Dwayne Brown

Headquarters, Washington

202-358-1726

dwayne.c.brown@nasa.gov


Brian Bell

California Institute of Technology, Pasadena

626-395-5832

bpbell@caltech.edu
Posted by Nelio Inacio at 1:24 PM 0 comments
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