Monday, July 21, 2014

WISE Catalog Just Got Wiser

WISE Catalog Just Got Wiser:

AllWISE Brings Galaxies Out of Hiding
The new AllWISE catalog will bring distant galaxies that were once invisible out of hiding, as illustrated in this image.
› Full image and caption


November 14, 2013

NASA's WISE mission has released a new and improved atlas and catalog brimming with data on three-quarters of a billion objects detected during two full scans of the sky.


WISE, which stands for Wide-field Infrared Survey Explorer, scanned the entire sky in infrared light in 2010, snapping a dozen pictures of every star and galaxy. By October of that year, the spacecraft ran out of the coolant needed to chill some of its heat-seeking detectors. NASA then decided to fund a second scan of the sky to look for asteroids and comets, in a project called NEOWISE.


But the images from that second sky scan were designed to catch moving asteroids, not stars and galaxies. Now NASA has funded a project called AllWISE to stack up all the WISE images, including those from the second sky scan, thereby doubling exposure times and making new stars and galaxies visible.


"By stacking up the data, we have created a monster database with dozens of individual measurements on every one of the infrared sources we detect," said Ned Wright of UCLA, the principal investigator of WISE.


One new feature of the enhanced WISE images is the ability to search for nearby stars, especially cooler ones that only show up in infrared light. Objects that are closer to us will appear to move across the sky over time in relation to background stars. This is the same reason why the planets march across our night skies while the stars seem to stay still. With the new atlas, astronomers can look at images of the sky taken six months apart; if something jumps across the images, then it must be located nearby and could be a never-before-seen neighbor.


The new catalog will also help with studies of distant galaxies, bringing those that were invisible to us before out of hiding.


"The extra depth of AllWISE lets us see galaxies so distant that their light was emitted in the first half of the history of the universe," said Peter Eisenhardt, the WISE project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif.


In addition to AllWISE, NASA decided to wake up the WISE spacecraft again to search for more asteroids (see http://www.jpl.nasa.gov/news/news.php?release=2013-257 ).


The technical details for accessing the AllWISE data are online at: http://wise2.ipac.caltech.edu/docs/release/allwise/ .


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages and operates the newly activated 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 is online at 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


2013-335
Posted by Nelio Inacio at 5:24 PM 0 comments
Labels: , ,

Update on Near-Earth Objects

Update on Near-Earth Objects:

The orbits of 2013 UQ4, 2013 US10 and 2013 UP8 are shown as viewed from within the plane of the solar system
The orbits of 2013 UQ4, 2013 US10 and 2013 UP8 are shown as viewed from within the plane of the solar system (ecliptic plane), which makes clear their highly inclined orbits relative to Earth's orbit.
Image credit: NASA/JPL-Caltech
› Larger image

November 18, 2013

Near-Earth Object 2013 US10 is a Long-Period Comet

Updated November 6, 2013


While initial reports from the Minor Planet Center in Cambridge, Mass., categorized object 2013 US10 as a very large near-Earth asteroid, new observations now indicate that it is, in fact, a long-period comet, and it is now designated C/2013 US10 (Catalina). The comet was discovered by the Catalina Sky Survey near Tucson, Ariz., on Oct. 31, 2013, and linked to earlier pre-discovery Catalina observations made on Sept. 12. The initial orbit suggested this object is a large, short period, near-Earth asteroid, as reported here yesterday. An updated orbit, issued today by the Minor Planet Center, removed the September 12 observations that belong to another object and include earlier pre-discovery August and September observations made by the Catalina Sky Survey, the ISON-HD observatory in Russia and Hawaii's Pan-STARRS group. The new orbit indicates that this object is in a long-period, near parabolic orbit about the sun. Furthermore, observations made last night at the Canada-France-Hawaii telescope indicate the object is showing modest cometary activity, which means that yesterday's rough estimate for the object's size (about 12 miles, or 20 kilometers) must now be completely revised. A new size estimate is not yet available, but the object could very well be much smaller than yesterday's estimate.


_________________________________________________________________________


Surprising Recent Discoveries of Three Large Near-Earth Objects

November 5, 2013


Two surprisingly large Near-Earth Asteroids have been discovered in just the last week or so, as well as a third moderately large asteroid which, surprisingly, has also gone undetected until now, even though it can pass close enough to Earth to be classified as "potentially hazardous." Not since 1983 has any near-Earth asteroid been found as large as the approximately 12-mile (20-kilometer) size of the two new large ones. In fact, there are only three other known near-Earth asteroids that are of comparable size or larger than the two new large ones.


It is important to note that none of these three new large near-Earth asteroids can come close enough to Earth to represent a near-term threat to our planet.


The first of the new large near-Earth asteroid discoveries is named 2013 UQ4, and it is perhaps the most unusual. This approximately 12-mile (19-kilometer) wide object was spotted by the Catalina Sky Survey on Oct. 23 when the asteroid was 270 million miles (435 million kilometers) away from Earth. Not only is this object unusually large, it follows a very unusual, highly inclined, retrograde orbit about the sun, which means it travels around the sun in the opposite direction of all the planets and the vast majority of asteroids.


The only objects usually found in retrograde orbits are comets, which suggests that 2013 UQ4 may be the remains of an old comet that no longer possesses the near-surface ices required for it to become active while near the sun. Comets that have exhausted most, or all, of their volatile ices do not spew dust during sweeps through the inner-solar system like their less-seasoned, more hyperactive space kin. Without the telltale comet tails or atmospheres, dead comets look like, and in fact for all practical purposes are, asteroids.


As reported on Circular No. 9262 of the International Astronomical Union, the Massachusett's Institute of Technology's Richard Binzel, David Polishook and Rachel Bowens-Rubin observed this object on October 31 with NASA's 3-meter Infrared Telescope Facility in Hawaii and determined this object belongs to the so-called X-type spectral class and exhibits no obvious comet-like activity. This implies about a 4 percent reflectivity, from which they estimate a diameter of approximately 12 miles (19 kilometers).


The second very large near-Earth object, named 2013 US10, was discovered on October 31 by the Catalina Sky Survey. While the reflectivity of this object has not yet been determined, and hence its diameter is still uncertain, it is also likely to be about 12 miles (20 kilometers) in size. Only three near-Earth asteroids (1036 Ganymed, 433 Eros and 3552 Don Quixote) are of comparable size or larger.


Why has it taken so long to discover these large near-Earth asteroids? The delay in discovering 2013 UQ4 is more easily understood because it has a very long orbital period that has kept it out of Earth's neighborhood for centuries. But the delayed discovery of 2013 US10 is a bit harder to explain, since current population models suggest that almost all near-Earth asteroids of this size and orbit should have already been found. A contributing factor may be that this object's orbit does not allow it to get closer than 50 million miles (80 million kilometers) of Earth's orbit, so the asteroid seldom gets close enough to Earth to become easily detectable. However, NASA-supported telescopic surveys are now covering more sky and looking "deeper" than they ever have before, and in fact, 2013 US10 was first detected where it spends much of its time, well beyond the orbit of Jupiter.


The third of the recent discoveries is the approximately 1.2-kilometer (two-kilometer) near-Earth asteroid 2013 UP8, found on Oct. 25 by the Pan-STARRS group in Hawaii. This asteroid can approach quite close to Earth's orbit, within 3.4 million miles (5.5 million kilometers), which makes it a "potentially hazardous asteroid" (PHA). 2013 UP8 is in the top 5th percentile of the largest PHAs, most of which were found much earlier during NASA's asteroid survey program. Like the other new discoveries, this asteroid has gone undetected for a long time because it has not approached Earth closely for decades. But the increasingly capable NASA-supported asteroid surveys finally found this object while it was still at a large distance from Earth, well beyond the orbit of Mars.


NASA's Near-Earth Object Program at NASA Headquarters, Washington, manages and funds the search, study and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.


More information about asteroids and near-Earth objects is available at: http://neo.jpl.nasa.gov/ , http://www.jpl.nasa.gov/asteroidwatch and via Twitter at http://www.twitter.com/asteroidwatch .

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


2013-336
Posted by Nelio Inacio at 5:24 PM 0 comments
Labels: , ,

Infant Galaxies Merge Near 'Cosmic Dawn'

Infant Galaxies Merge Near 'Cosmic Dawn':

Three-headed Galactic Blob
The big blob-like structure shown here, named Himiko after the legendary ancient queen of Japan, turns out to be three galaxies thought to be in the process of merging into one. In this image, infrared data from NASA's Spitzer Space Telescope are red; visible data from NASA's Hubble Space Telescope are green; and ultraviolet data from Japan's Subaru telescope on Mauna Kea, Hawaii are blue.
› Full image and caption


November 21, 2013

Astronomers using the combined power of the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile and NASA's Hubble and Spitzer space telescopes have discovered a far-flung trio of primitive galaxies nestled inside an enormous blob of primordial gas nearly 13 billion light-years from Earth. It's possible the trio will eventually merge into a single galaxy similar to our own Milky Way.


"This exceedingly rare triple system, seen when the universe was only 800 million years old, provides important insights into the earliest stages of galaxy formation during a period known as 'cosmic dawn,' when the universe was first bathed in starlight," said Richard Ellis of the California Institute of Technology, Pasadena, a member of the research team.


Researchers first detected this object, which appeared to be a giant bubble of hot, ionized gas, in 2009. Dubbed Himiko (after a legendary queen of ancient Japan), it is nearly 10 times larger than typical galaxies of that era and comparable in size to our own Milky Way. Subsequent infrared observations with NASA's Spitzer Space Telescope provided more clues about the object's mass, suggesting Himiko might represent a single galaxy, which would make it uncharacteristically massive for that period of the early universe.


"The new observations revealed that, rather than a single galaxy, Himiko harbors three distinct, bright sources, whose intense star formation is heating and ionizing this giant cloud of gas," said Masami Ouchi, an associate professor at the University of Tokyo who led the international team of astronomers from Japan and the United States.


New data from ALMA, Hubble and Spitzer also led astronomers to speculate that Himiko could be made up almost entirely of primordial gas, a mixture of the light elements hydrogen and helium, which were created in the Big Bang event that gave birth to our universe. If correct, this would be a landmark discovery signaling the detection of a primordial galaxy seen during its formation.


The results are accepted for publication in the Astrophysical Journal.


Read the full ALMA news release online at: https://public.nrao.edu/news/pressreleases/infant-galaxies-merge-near-cosmic-dawn .


Read the Caltech news release at: http://www.caltech.edu/content/himiko-and-cosmic-dawn .


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 Caltech. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. 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 .


ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-338
Posted by Nelio Inacio at 5:23 PM 0 comments
Labels: , ,

Three Questions About Comet ISON

Three Questions About Comet ISON:

Comet ISON appeared in the higher-resolution HI-1 camera on NASA's STEREO-A spacecraft.
Comet ISON appeared in the higher-resolution HI-1 camera on NASA's STEREO-A spacecraft. Dark "clouds" coming from the right are more dense areas in the solar wind, causing ripples in Comet Encke's tail. Using comet tails as tracers can provide valuable data about solar wind conditions near the sun. Image Credit:
Karl Battams/NASA/STEREO/CIOC
› Larger image

November 25, 2013

Don Yeomans, a senior research scientist at JPL, keeps a watchful eye on near-Earth objects -- asteroids, comets and other space rocks. Yeomans heads a group charged by NASA to watch for objects whose orbits bring them close to Earth.


Below is a comet ISON Q&A with Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory, Pasadena, Calif.


What is so interesting about comet ISON?

There's great interest in comet ISON for a couple of reasons. First of all, it's coming from the very edge of our solar system so it stills retains the primordial ices from which it formed four-and-a-half billion years ago. It's been traveling from the outer edge of the solar system for about five-and-a-half million years to reach us in the inner solar system, and it's going to make an extremely close approach to the sun and hence could become very bright and possibly a very easy naked-eye object in early December.


What will happen to comet ISON on Thanksgiving?

So there are three possibilities when this comet rounds the sun on Thanksgiving Day 2013 [Nov. 28]. It could be tough enough to survive the passage of the sun and be a fairly bright naked-eye object in the early morning sky in the first week of December. Or, the sun could actually pull it apart. The tidal forces could actually pull this comet apart and so it becomes several chunks rounding the sun and putting on a great show again in early December. Or, if the comet is very weak, it could break up into a cloud of dust and be a complete bust in December.


Do comets like ISON present a scientific opportunity?

There is going to be a small army of amateur and professional astronomers on the Earth, and spacecraft are going to be observing this object near the sun. So we're going to find out a great deal about what this comet is made of, and hence we are going to find out a great deal about what the solar system was like four-and-a-half billion years ago.


To learn more about comet ISON, go to www.nasa.gov/ison .

NASA's Near-Earth Object Program at NASA Headquarters, Washington, manages and funds the search, study and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.


More information about asteroids and near-Earth objects is available at: http://neo.jpl.nasa.gov/ , http://www.jpl.nasa.gov/asteroidwatch and via Twitter at http://www.twitter.com/asteroidwatch .

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


2013-341
Posted by Nelio Inacio at 5:22 PM 0 comments
Labels: , ,

Do Black Holes Come in Size Medium?

Do Black Holes Come in Size Medium?:

Topsy Turvy Black Holes
The magenta spots in this image show two black holes in the spiral galaxy called NGC 1313, or the Topsy Turvy galaxy. Both black holes belong to a class called ultraluminous X-ray sources, or ULXs. The magenta X-ray data come from NASA's Nuclear Spectroscopic Telescopic Array, and are overlaid on a visible image from the Digitized Sky Survey. Image credit: NASA/JPL-Caltech/IRAP
› Full image and caption

November 26, 2013

Black holes can be petite, with masses only about 10 times that of our sun -- or monstrous, boasting the equivalent in mass up to 10 billion suns. Do black holes also come in size medium? NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, is busy scrutinizing a class of black holes that may fall into the proposed medium-sized category.


"Exactly how intermediate-sized black holes would form remains an open issue," said Dominic Walton of the California Institute of Technology, Pasadena. "Some theories suggest they could form in rich, dense clusters of stars through repeated mergers, but there are a lot of questions left to be answered."


The largest black holes, referred to as supermassive, dominate the hearts of galaxies. The immense gravity of these black holes drags material toward them, forcing the material to heat up and release powerful X-rays. Small black holes dot the rest of the galactic landscape. They form under the crush of collapsing, dying stars bigger than our sun.


Evidence for medium-sized black holes lying somewhere between these two extremes might come from objects called ultraluminous X-ray sources, or ULXs. These are pairs of objects in which a black hole ravenously feeds off a normal star. The feeding process is somewhat similar to what happens around supermassive black holes, but isn't as big and messy. In addition, ULXs are located throughout galaxies, not at the cores.


The bright glow of X-rays coming from ULXs is too great to be the product of typical small black holes. This and other evidence indicates the objects may be intermediate in mass, with 100 to 10,000 times the mass of our sun. Alternatively, an explanation may lie in some kind of exotic phenomenon involving extreme accretion, or "feeding," of a black hole.


NuSTAR is joining with other telescopes to take a closer look at ULXs. It's providing the first look at these objects in focused, high-energy X-rays, helping to get better estimates of their masses and other characteristics.


In a new paper from Walton and colleagues accepted for publication in the Astrophysical Journal, the astronomers report serendipitously finding a ULX that had gone largely unnoticed before. They studied the object, which lies in the Circinus spiral galaxy 13 million light-years away, not only with NuSTAR but also with the European Space Agency's XMM-Newton satellite. Archival data from NASA's Chandra, Swift and Spitzer space telescopes as well as Japan's Suzaku satellite, were also used for further studies. "We went to town on this object, looking at a range of epochs and wavelengths," said Walton.


The results indicate the black hole in question is about 100 times the mass of the sun, putting it right at the border between small and medium black holes.


In another accepted Astrophysical Journal paper, Matteo Bachetti of the Institut de Recherche en Astrophysique et Planétologie and colleagues looked at two ULXs in NGC 1313, a spiral galaxy known as the "Topsy Turvy galaxy," also about 13 million light-years way.


These are among the best-studied ULXs known. A single viewing with NuSTAR showed that the black holes didn't fit with models of medium-size black holes. As a result, the researchers now think both ULXs harbor small, stellar-mass black holes. One of the objects is estimated to be big for its size category, at 70 to 100 solar masses.


"It's possible that these objects are ultraluminous because they are accreting material at a high rate and not because of their size," said Bachetti. "If intermediate-mass black holes are out there, they are doing a good job of hiding from us."


NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley; Columbia University, New York; NASA's Goddard Space Flight Center, Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Livermore, Calif.; ATK Aerospace Systems, Goleta, Calif., and with support from the Italian Space Agency (ASI) Science Data Center.


NuSTAR's mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located at Malindi, Kenya. The mission's outreach program is based at Sonoma State University, Rohnert Park, Calif. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-343
Posted by Nelio Inacio at 5:22 PM 0 comments
Labels: , ,

Scientists Seek Other Scientists for Cosmology Problem

Scientists Seek Other Scientists for Cosmology Problem:

Warped Galaxies Quiz
Can you match each galaxy in the top row with its warped counterpart in the bottom row? For example, is the warped version of galaxy A in box D, E, or F? › Click for full-size quiz image  |  › See answers

November 26, 2013

How do you measure something that is invisible? It's a challenging task, but astronomers have made progress on one front: the study of dark matter and dark energy, two of the most mysterious substances in our cosmos. Dark matter is intermixed with normal matter, but it gives off no light, making it impossible to see. Dark energy is even more slippery, yet scientists think it works against gravity to pull our universe apart at the seams.


Now for the third time, an innovative competition has begun again with the goal of finding better tools for probing dark matter and dark energy. Called GREAT3, which stands for GRavitational lEnsing Accuracy Testing 3, the event is sponsored by NASA's Jet Propulsion Laboratory, Pasadena, Calif., and a European Union Network of Excellence called Pattern Analysis, Statistical Modeling and Computation Learning 2 (PASCAL2).


The idea behind the challenge is to spur scientists, including those from fields outside astronomy, to come up with new insight into the problems of measuring dark matter and dark energy. Contestants are asked to solve galaxy puzzles involving millions of images from NASA's Hubble Space Telescope. A better understanding of the "dark side of the cosmos" may reveal new information about the very fabric and fate of our universe.


The first two challenges were a big success, attracting new brainpower to the field, including scientists from machine learning and particle physics. Machine learning involves programming computers to learn on their own using actual data from the real world. It has several applications, such as facial-recognition software, medical diagnostics and spam filtering, to name a few.


"Other data scientists have been thinking about the same type of algorithms we need for our cosmology tools for a long time," said Jason Rhodes of JPL. "We want to acquire that knowledge and see this field grow."


One of the most powerful tools for studying dark matter and dark energy is gravitational lensing. When dark matter lies between us and a distant galaxy, the light of the galaxy can be warped by the gravity from the dark matter. By measuring this warping, scientists can map dark matter, despite it being invisible. What's more, by looking at the distribution of dark and normal matter in our universe, scientists can get a better handle on dark energy and how it battles gravity to slow the growth of galactic structures.


In some cases of gravitational lensing, galaxies look wacky, as if seen in a funhouse mirror, or they appear multiple times. This is referred to as strong lensing. But in most cases, called weak lensing, the warping effects are tiny and impossible to see by eye.


The GREAT3 challenge is designed to improve methods for measuring weak lensing in preparation for future dark matter/dark energy missions, such as the European Space Agency's Euclid, in which NASA plays an important role, and the National Academy of Science's highest priority for NASA, WFIRST -- also known as the WFIRST-AFTA mission, which stands for Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets.


The millions of images given to GREAT3 contestants show galaxies that have been artificially warped via weak lensing. The puzzle is to figure out precisely how the galaxy images were warped, a complex task that involves looking for patterns and sifting out artificial warping effects caused by telescope optics and the atmosphere.


The winner will be announced in May 2014 and will receive $3,000 worth of computing equipment, the perfect gift for programmers hoping to crack more cosmic codes.


"With these contests, we have seen new ideas seeping into our field," said Rachel Mandelbaum of Carnegie Mellon University, Pittsburgh, who is working with Rhodes and Barnaby Rowe of UCL (University College London), England, to organize the challenge, along with a special committee. "It's a fun problem to work on and it's a problem that needs to be solved."


A visual quiz involving strongly lensed, or warped, galaxies is at: http://www.nasa.gov/jpl/news/galaxy20131126.html .


More information about the competition is online at: http://great3challenge.info/ .


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

Whitney Clavin (818) 354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-342
Posted by Nelio Inacio at 5:22 PM 0 comments
Labels: , ,

NASA Holds Google+ Hangout on Cassini's Findings at Saturn

NASA Holds Google+ Hangout on Cassini's Findings at Saturn:

The Day the Earth Smiled
On July 19, 2013, in an event celebrated the world over, NASA's Cassini spacecraft slipped into Saturn's shadow and turned to image the planet, seven of its moons, its inner rings -- and, in the background, our home planet, Earth. Image credit: NASA/JPL-Caltech/SSI
› Full image and caption


December 02, 2013

NASA will host a Google+ Hangout at 12:30 p.m. PST (3:30 p.m. EST) on Wednesday, Dec. 4, to discuss images of Saturn taken by the agency's Cassini spacecraft. The Hangout also will look ahead to the next few years of the Cassini mission.


The event will also be broadcast live on NASA Television and streamed on the agency's website.


The panelists are:

-- Kunio Sayanagi, Cassini imaging team associate, Hampton University, Va.

-- Carolyn Porco, Cassini imaging team lead, Space Science Institute, Boulder, Colo.

-- Linda Spilker, Cassini project scientist, NASA's Jet Propulsion Laboratory, Pasadena, Calif.

-- Earl Maize, Cassini program manager, JPL



Reporters and the public can ask questions on the Google+ Hangout event page, in the chat box on the Ustream site and via Twitter using the hashtag #askCassini.


The Google+ Hangout will be available at: http://bit.ly/askcassini .


For NASA TV streaming video, downlink and scheduling information, visit:
http://www.nasa.gov/nasatv .


The event will be streamed live on Ustream with a moderated chat available at: http://www.ustream.com/nasajpl2 .


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

Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-344
Posted by Nelio Inacio at 5:21 PM 0 comments
Labels: , ,

Massive Black Hole Duo: Possible Sighting by NASA's WISE

Massive Black Hole Duo: Possible Sighting by NASA's WISE:

Two Black Holes on Way to Becoming One
Two black holes are entwined in a gravitational tango in this artist's conception. Supermassive black holes at the hearts of galaxies are thought to form through the merging of smaller, yet still massive black holes, such as the ones depicted here. Image credit: NASA
› Full image and caption

December 03, 2013

Astronomers have spotted what appear to be two supermassive black holes at the heart of a remote galaxy, circling each other like dance partners. The incredibly rare sighting was made with the help of NASA's Wide-field Infrared Survey Explorer, or WISE.


Follow-up observations with the Australian Telescope Compact Array near Narrabri, Australia, and the Gemini South telescope in Chile, revealed unusual features in the galaxy, including a lumpy jet thought to be the result of one black hole causing the jet of the other to sway.


"We think the jet of one black hole is being wiggled by the other, like a dance with ribbons," said Chao-Wei Tsai of NASA's Jet Propulsion Laboratory, Pasadena, Calif., who is lead author of a paper on the findings appearing in the Dec. 10 issue of Astrophysical Journal. "If so, it is likely the two black holes are fairly close and gravitationally entwined."


The findings could teach astronomers more about how supermassive black holes grow by merging with each other.


The WISE satellite scanned the entire sky twice in infrared wavelengths before being put into hibernation in 2011. NASA recently gave the spacecraft a second lease on life, waking it up to search for asteroids, in a project called NEOWISE.


The new study took advantage of previously released all-sky WISE data. Astronomers sifted through images of millions of actively feeding supermassive black holes spread throughout our sky before an oddball, also known as WISE J233237.05-505643.5, jumped out.


"At first we thought this galaxy's unusual properties seen by WISE might mean it was forming new stars at a furious rate," said Peter Eisenhardt, WISE project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and a co-author of the study. "But on closer inspection, it looks more like the death spiral of merging giant black holes."


Almost every large galaxy is thought to harbor a supermassive black hole filled with the equivalent in mass of up to billions of suns. How did the black holes grow so large? One way is by swallowing ambient materials. Another way is through galactic cannibalism. When galaxies collide, their massive black holes sink to the center of the new structure, becoming locked in a gravitational tango. Eventually, they merge into one even-more-massive black hole.


The dance of these black hole duos starts out slowly, with the objects circling each other at a distance of about a few thousand light-years. So far, only a few handfuls of supermassive black holes have been conclusively identified in this early phase of merging. As the black holes continue to spiral in toward each other, they get closer, separated by just a few light-years.


It is these close-knit black holes, also called black hole binaries, that have been the hardest to find. The objects are usually too small to be resolved even by powerful telescopes. Only a few strong candidates have been identified to date, all relatively nearby. The new WISE J233237.05-505643.5 is a new candidate, and located much farther away, at 3.8 billion light-years from Earth.


Radio images with the Australian Telescope Compact Array were key to identifying the dual nature of WISE J233237.05-505643.5. Supermassive black holes at the cores of galaxies typically shoot out pencil-straight jets, but, in this case, the jet showed a zigzag pattern. According to the scientists, a second massive black hole could, in essence, be pushing its weight around to change the shape of the other black hole's jet.


Visible-light spectral data from the Gemini South telescope in Chile showed similar signs of abnormalities, thought to be the result of one black hole causing disk material surrounding the other black hole to clump. Together, these and other signs point to what is probably a fairly close-knit set of circling black holes, though the scientists can't say for sure how much distance separates them.


"We note some caution in interpreting this mysterious system," said Daniel Stern of JPL, a co-author of the study. "There are several extremely unusual properties to this system, from the multiple radio jets to the Gemini data, which indicate a highly perturbed disk of accreting material around the black hole, or holes. Two merging black holes, which should be a common event in the universe, would appear to be simplest explanation to explain all the current observations."


The final stage of merging black holes is predicted to send gravitational waves rippling through space and time. Researchers are actively searching for these waves using arrays of dead stars called pulsars in hopes of learning more about the veiled black hole dancers (see http://www.nasa.gov/centers/jpl/news/pulsar20131106.html ).


The technical paper is online at http://arxiv.org/abs/1310.2257 .


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages and operates the WISE 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 is online at 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


2013-345
Posted by Nelio Inacio at 5:18 PM 0 comments
Labels: , ,

NASA's Dawn Fills out its Ceres Dance Card

NASA's Dawn Fills out its Ceres Dance Card:

On the Way to Ceres
This artist's concept shows NASA's Dawn spacecraft heading toward the dwarf planet Ceres. Dawn spent nearly 14 months orbiting Vesta, the second most massive object in the main asteroid belt between Mars and Jupiter, from 2011 to 2012. It is heading towards Ceres, the largest member of the asteroid belt. When Dawn arrives, it will be the first spacecraft to go into orbit around two destinations in our solar system beyond Earth. Image credit: NASA/JPL-Caltech
› Full image and caption

December 03, 2013

It's going to be a ball when NASA's Dawn spacecraft finally arrives at the dwarf planet Ceres, and mission managers have now inked in the schedule on Dawn's dance card.


Dawn has been cruising toward Ceres, the largest object in the main asteroid belt between Mars and Jupiter, since September 2012. That's when it departed from its first dance partner, Vesta.


Ceres presents an icy -- possibly watery -- counterpoint to the dry Vesta, where Dawn spent almost 14 months. Vesta and Ceres are two of the largest surviving protoplanets -- bodies that almost became planets -- and will give scientists clues about the planet-forming conditions at the dawn of our solar system.


When Dawn enters orbit around Ceres, it will be the first spacecraft to see a dwarf planet up-close and the first spacecraft to orbit two solar system destinations beyond Earth.


"Our flight plan around Ceres will be choreographed to be very similar to the strategy that we successfully used around Vesta," said Bob Mase, Dawn's project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This approach will build on that and enable scientists to make direct comparisons between these two giants of the asteroid belt."


As a prelude, the team will begin approach operations in late January 2015. The next month, Ceres will be big enough in Dawn's view to be imaged and used for navigation purposes. Dawn will arrive at Ceres -- or, more accurately, it will be captured by Ceres' gravity -- in late March or the beginning of April 2015.


Dawn will make its first full characterization of Ceres later in April, at an altitude of about 8,400 miles (13,500 kilometers) above the icy surface. Then, it will spiral down to an altitude of about 2,750 miles (4,430 kilometers), and obtain more science data in its survey science orbit. This phase will last for 22 days, and is designed to obtain a global view of Ceres with Dawn's framing camera, and global maps with the visible and infrared mapping spectrometer (VIR).


Dawn will then continue to spiral its way down to an altitude of about 920 miles (1,480 kilometers), and in August 2015 will begin a two-month phase known as the high-altitude mapping orbit. During this phase, the spacecraft will continue to acquire near-global maps with the VIR and framing camera at higher resolution than in the survey phase. The spacecraft will also image in "stereo" to resolve the surface in 3-D.


Then, after spiraling down for two months, Dawn will begin its closest orbit around Ceres in late November, at a distance of about 233 miles (375 kilometers). The dance at low-altitude mapping orbit will be a long waltz -- three months -- and is specifically designed to acquire data with Dawn's gamma ray and neutron detector (GRaND) and gravity investigation. GRaND will reveal the signatures of the elements on and near the surface. The gravity experiment will measure the tug of the dwarf planet, as monitored by changes in the high-precision radio link to NASA's Deep Space Network on Earth.


At this low-altitude mapping orbit, Dawn will begin using a method of pointing control that engineers have dubbed "hybrid" mode because it utilizes a combination of reaction wheels and thrusters to point the spacecraft. Up until this final mission phase, Dawn will have used just the small thruster jets, which use a fuel called hydrazine, to control its orientation and pointing. While it is possible to explore Ceres completely using only these jets, mission managers want to conserve precious fuel. At this lowest orbit, using two of the reaction wheels to help with pointing will provide the biggest hydrazine savings. So Dawn will be spinning up two of the gyroscope-like devices to aid the thrusters.


In 2011, the Dawn team prepared the capability to operate in a hybrid mode, but it wasn't needed during the Vesta mission. It was only when a second (of four) reaction wheels developed excessive friction while Dawn was leaving Vesta in 2012 that mission managers decided to use the hybrid mode at Ceres. To prove the technique works, Dawn engineers completed a 27-hour in-flight test of the hybrid mode, ending on Nov. 13. It operated just as expected.


"The successful test of this new way to control our orientation gives us great confidence that we'll have a steady hand at Ceres, which will enable us to get really close to a world that we only know now as a fuzzy dot amidst the stars," said Marc Rayman, Dawn's chief engineer and mission director, based at JPL.


Of course, mission planners have built some extra days into the schedule to account for the small uncertainty in the efficiency of the solar arrays at such a large distance from the sun, where sunlight will be very faint. The solar arrays provide power to the ion propulsion system, in addition to operating power for the spacecraft and instruments. Mission planners also account for potential variations in the gravity field of Ceres, which will not be known precisely until Dawn measures them.


"We are expecting changes when we get to Ceres and, fortunately, we built a very capable spacecraft and developed flexible plans to accommodate the unknowns," said Rayman. "There's great excitement in the unexpected -- that's part of the thrill of exploration."


Starting on Dec. 27, Dawn will be closer to Ceres than it will be to Vesta.


"This transition makes us eager to see what secrets Ceres will reveal to us when we get up close to this ancient, giant, icy body," said Christopher Russell, Dawn's principal investigator, based at UCLA. "While Ceres is a lot bigger than the candidate asteroids that NASA is working on sending humans to, many of these smaller bodies are produced by collisions with larger asteroids such as Ceres and Vesta. It is of much interest to determine the nature of small asteroids produced in collisions with Ceres. These might be quite different from the small rocky asteroids associated with Vesta collisions."


Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. The California Institute of Technology in Pasadena manages JPL for NASA.


To learn more about hybrid mode at Ceres, read Rayman's Dawn Journal [link].


For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .


To learn more about hybrid mode at Ceres, read Rayman's Dawn Journal .

Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


2013-347
Posted by Nelio Inacio at 5:18 PM 0 comments
Labels: , ,

NASA's Cassini Spacecraft Obtains Best Views of Saturn Hexagon

NASA's Cassini Spacecraft Obtains Best Views of Saturn Hexagon:

In Full View: Saturn's Streaming Hexagon
This colorful view from NASA's Cassini mission is the highest-resolution view of the unique six-sided jet stream at Saturn's north pole known as "the hexagon." This movie, made from images obtained by Cassini's imaging cameras, is the first to show the hexagon in color filters, and the first movie to show a complete view from the north pole down to about 70 degrees north latitude. Image credit: NASA/JPL-Caltech/SSI/Hampton University
› Full image and caption


December 04, 2013

NASA's Cassini spacecraft has obtained the highest-resolution movie yet of a unique six-sided jet stream, known as the hexagon, around Saturn's north pole.


This is the first hexagon movie of its kind, using color filters, and the first to show a complete view of the top of Saturn down to about 70 degrees latitude. Spanning about 20,000 miles (30,000 kilometers) across, the hexagon is a wavy jet stream of 200-mile-per-hour winds (about 322 kilometers per hour) with a massive, rotating storm at the center. There is no weather feature exactly, consistently like this anywhere else in the solar system.


"The hexagon is just a current of air, and weather features out there that share similarities to this are notoriously turbulent and unstable," said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena. "A hurricane on Earth typically lasts a week, but this has been here for decades -- and who knows -- maybe centuries."


Weather patterns on Earth are interrupted when they encounter friction from landforms or ice caps. Scientists suspect the stability of the hexagon has something to do with the lack of solid landforms on Saturn, which is essentially a giant ball of gas.


Better views of the hexagon are available now because the sun began to illuminate its interior in late 2012. Cassini captured images of the hexagon over a 10-hour time span with high-resolution cameras, giving scientists a good look at the motion of cloud structures within.


They saw the storm around the pole, as well as small vortices rotating in the opposite direction of the hexagon. Some of the vortices are swept along with the jet stream as if on a racetrack. The largest of these vortices spans about 2,200 miles (3,500 kilometers), or about twice the size of the largest hurricane recorded on Earth.


Scientists analyzed these images in false color, a rendering method that makes it easier to distinguish differences among the types of particles suspended in the atmosphere -- relatively small particles that make up haze -- inside and outside the hexagon.


"Inside the hexagon, there are fewer large haze particles and a concentration of small haze particles, while outside the hexagon, the opposite is true," said Kunio Sayanagi, a Cassini imaging team associate at Hampton University in Virginia. "The hexagonal jet stream is acting like a barrier, which results in something like Earth's Antarctic ozone hole."


The Antarctic ozone hole forms within a region enclosed by a jet stream with similarities to the hexagon. Wintertime conditions enable ozone-destroying chemical processes to occur, and the jet stream prevents a resupply of ozone from the outside. At Saturn, large aerosols cannot cross into the hexagonal jet stream from outside, and large aerosol particles are created when sunlight shines on the atmosphere. Only recently, with the start of Saturn's northern spring in August 2009, did sunlight begin bathing the planet's northern hemisphere.


"As we approach Saturn's summer solstice in 2017, lighting conditions over its north pole will improve, and we are excited to track the changes that occur both inside and outside the hexagon boundary," said Scott Edgington, Cassini deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.


A black-and-white version of the imaging camera movie and movies obtained by Cassini's visual and infrared mapping spectrometer are also tools Cassini scientists can use to look at wind speeds and the mini-storms inside the jet stream.


Cassini launched in 1997 and arrived at Saturn on July 1, 2004. Its mission is scheduled to end in September 2017. 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. JPL designed, developed and assembled the Cassini orbiter and its two onboard cameras. The imaging team is based at the Space Science Institute, Boulder, Colo.


A Google+ Hangout to discuss these results and other Cassini images will take place today at 12:30 p.m. PST (3:30 p.m. EST): http://bit.ly/askcassini .


The event will be broadcast live on NASA Television and streamed on the agency's website. For information on NASA TV, visit: http://www.nasa.gov/ntv .


The event will also be streamed live on Ustream with a moderated chat available at: http://www.ustream.tv/nasajpl2 .


Questions can be asked on the Google Hangout event page, in the chat box on the Ustream site and via Twitter using the hashtag #askCassini.


More information about Cassini 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.

jccook@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-350
Posted by Nelio Inacio at 5:12 PM 0 comments
Labels: , ,

Thinking Inside the Box, Launching into Space

Thinking Inside the Box, Launching into Space:

NASA CubeSats Heading into Orbit
The NROL-39 GEMSat mission lifted off from California's Vandenberg Air Force Base on Dec. 5, 2013, aboard a United Launch Alliance Atlas V rocket. The mission includes two NASA Earth-orbiting cube satellites ("CubeSats") led by NASA's Jet Propulsion Laboratory, Pasadena, Calif.: the Intelligent Payload Experiment (IPEX) and M-Cubed/COVE. Image credit: P. Corkery/ULA

› Larger image

December 06, 2013

Two tiny, cube-shaped research satellites hitched a ride to Earth orbit to validate new hardware and software technologies for future NASA Earth-observing instruments.


The cube satellites, or "CubeSats," which typically have a volume of exactly 33.814 ounces (1 liter), were launched on a United Launch Alliance Atlas V rocket at 11:14 p.m. PST last night (Dec. 5) from California's Vandenberg Air Force Base as part of the NROL-39 GEMSat mission. Led by NASA's Jet Propulsion Laboratory, Pasadena, Calif., and developed with university and industry partners, these two CubeSats will help enable near-real-time processing capabilities relevant to future climate science measurements.


One of the CubeSats that launched was developed in collaboration with California Polytechnic State University, San Luis Obispo, and is called the Intelligent Payload Experiment, or IPEX. It enables imagery to be transmitted more rapidly from satellite missions back to Earth. By using new software and algorithms, the spacecraft can sift through the data, looking only for the most important images that the scientists urgently need on the ground. This method is designed to speed delivery time of critical data products from days to minutes.


"IPEX will demonstrate software that will enable future NASA missions to recognize science events such as flooding, volcanism and wildfires, and respond by sending alerts and autonomously acquiring follow-up imagery," said Steve Chien of JPL, principal investigator for the IPEX mission.


The other CubeSat launched is the Michigan Multipurpose Mini-satellite/CubeSat On-board processing Validation Experiment, or M-Cubed/COVE.


M-Cubed, developed in partnership with the University of Michigan, Ann Arbor, will image Earth. The COVE payload will use these data to validate an instrument image data processing algorithm that will greatly reduce the science data transmission rate required for on-orbit operations.


"The COVE payload will advance processor and algorithm technology designed for use in a future science instrument to characterize properties of aerosols and clouds, which will help our understanding of global climate change," said Paula Pingree of JPL, principal investigator of the MCubed/COVE-2 mission.


These technology validation missions are sponsored by NASA's Earth Science Technology Office. They are designed to satisfy their science objectives within six months, but will remain in Earth orbit for many years.


The California Institute of Technology in Pasadena manages JPL for NASA.
For additional information on NASA's CubeSat Launch Initiative program, visit: http://go.nasa.gov/nXOuPI .

David Israel 818-354-4797

Jet Propulsion Laboratory, Pasadena, Calif.

david.israel@jpl.nasa.gov


Joshua Buck 202-358-1100

NASA Headquarters, Washington

jbuck@nasa.gov


2013-353
Posted by Nelio Inacio at 5:09 PM 0 comments
Labels: , ,

NASA Highlights Mars, Earth and Other Science at AGU Event

NASA Highlights Mars, Earth and Other Science at AGU Event:

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


December 06, 2013

NASA researchers, including some from the Jet Propulsion Laboratory, will present new findings on a wide range of Earth and space science topics next week at the annual meeting of the American Geophysical Union (AGU).


The meeting will take place Dec. 9 to 13 at the Moscone Convention Center in San Francisco.


Some news conference will be available via live streaming at http://www.ustream.tv/nasajpl2, as follows:


Monday, 9 a.m. PSTCuriosity Rover Update

Monday, 10:30 a.m. PST Mapping Snowpack from the Sky

Tuesday, 9 a.m. PST Improving Natural Hazard Warnings

Tuesday, 10:30 a.m. PST News from Juno's Earth Flyby

Tuesday, 11:30 a.m. PST Dynamic Mars Over Time

Thursday, 11:30 a.m. PST New Results from Cassini Mission to Saturn


The briefings will not be carried on NASA Television.


After the Curiosity briefing on Dec. 9 hosted by AGU, a NASA media teleconference will be held at 10 a.m. PST (1 p.m. EST) to discuss the new results from the Radiation Assessment Detector on Curiosity. Audio will be streamed live on NASA's website at: http://www.nasa.gov/newsaudio .
NASA's media briefings during the meeting will feature topics such as the latest discoveries from Mars. Saturn's moon Titan, prospects for the recovery of the Antarctic ozone hole, Comet ISON, and close-up views of the sun from a NASA spacecraft launched this year.


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

Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

stephen.e.cole@nasa.gov


2013-352
Posted by Nelio Inacio at 5:05 PM 0 comments
Labels: , ,

NASA Snow Mapper Reaps Big Benefits for California

NASA Snow Mapper Reaps Big Benefits for California:

Spatial distribution of snow water equivalent across the Tuolumne River Basin
Spatial distribution of snow water equivalent across the Tuolumne River Basin from April 10 to June 1, 2013 as measured by NASA's Airborne Snow Observatory. Image credit: NASA/JPL-Caltech
› Full image and caption


December 09, 2013

Unprecedented snowpack maps from NASA's prototype Airborne Snow Observatory mission helped water managers for 2.6 million residents of the San Francisco Bay Area achieve near-perfect water operations this summer, despite the driest year in California's recorded history.


The high-resolution NASA snow maps of the Tuolumne River Basin in the Sierra Nevada helped optimize reservoir filling and hydroelectric generation at the Hetch Hetchy reservoir and its O'Shaughnessy Dam. This resulted in a full reservoir at the end of the snowmelt season, no water spillage, and generation of more than $3.9 million in hydropower. The NASA data helped optimize operations during the last two critical weeks of runoff.


At a media briefing today at the American Geophysical Union meeting in San Francisco, scientists from NASA; the University of Washington, Seattle; and McGurk Hydrologic Associates, Orinda, Calif., discussed the observatory's first year of operations in California and the Uncompahgre watershed in Colorado's Upper Colorado River Basin. The three-year demonstration mission is a collaboration between NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the California Department of Water Resources in Sacramento.


"For the first time, Airborne Snow Observatory data are telling us the total water in the snowpack in the watershed and the absorption of sunlight that control its melt speed, enabling us to estimate how much water will flow out of a basin when the snow melts," said Tom Painter, observatory principal investigator at JPL. "By combining near-real-time information on the total amount of water in the snowpack with observations of water inflow to Hetch Hetchy reservoir between April and July, we were able to greatly improve the model we developed to predict inflow into the reservoir."


Painter said this helped reservoir managers more efficiently allocate water inflow between power generation, water supplies and ecological purposes.


He noted that the improved snowpack measurements and more efficient reservoir operations are vital in the face of continued climate change, larger weather uncertainties, California's continuing severe drought and increasing demand for water.


Flying aboard a Twin Otter aircraft, the Airborne Snow Observatory measures two properties most critical to understanding snowmelt runoff and timing: snow depth and snow reflectivity. By combining snow depth with estimated density, snow water equivalent -- the amount of water in the snow -- is derived and used to calculate the amount of water that will run off. Snow reflectivity, or albedo, is the fraction of the incoming amount of sunlight reflected by snow. Subtracting reflected sunlight from incoming sunlight gives the absorbed sunlight, which largely controls the speed of snowmelt and timing of its runoff.


Before now, Tuolumne River Basin runoff forecasts could only be made using monthly manual ground snow surveys and daily automated measurement devices called snow pillows at sparsely located sites in lower to middle elevations. As those sites melt free of snow in early spring, an unknown amount of snow remains at higher elevations. The total area of the basin measured at all of these survey sites is only about 270 square feet (25 square meters). The observatory measured all the snow in the basin over an area 46 million times larger: 460 square miles (1,140 square kilometers).


The observatory mapped the basin weekly from early April through early June. Over 65 days, it measured the decline in water volume as the Hetch Hetchy basin snowpack melted, shrinking from 218.1 thousand acre-feet (71.06 billion gallons) to 15.2 thousand acre-feet (4.94 billion gallons). An acre-foot is the amount of water needed to cover an acre of land to a depth of one foot, or 325,851 gallons. For comparison, the average family of four uses about an acre-foot per year.


Every day in summer, 290 million gallons, or 870 acre-feet, come out of Hetch Hetchy and travel 150 miles (241 kilometers) to the San Francisco Peninsula, providing all or some of the water for 2.6 million customers. When full, the 8-mile-long (13-kilometer) reservoir holds 360.4 thousand acre-feet. The reservoir's water level is typically lowered about a third of the way (about 120 feet, or 37 meters) every summer.


In early June, a modeling forecast of predicted water inflow to the reservoir that had been corrected using Airborne Snow Observatory data was used to supplement the City of San Francisco's Hetch Hetchy Water & Power managers' existing models as they topped off the reservoir. Hydrologist Bruce McGurk of McGurk Hydrologic, Orinda, Calif., provided the results from a daily forecasting model he built to use with observatory results. Without the observatory data, his model over-predicted by 32,000 acre-feet the amount of water that would flow into the reservoir. Had all that water been used to generate power, it would have drafted the reservoir down 16 feet (4.9 meters) - water supplies that would not have been available to the thirsty city this summer. "The Airborne Snow Observatory provides information on snow depth and water quantity at weekly intervals that water managers have never had before, but have always wanted," McGurk said.


Beyond its water management applications, Associate Professor Jessica Lundquist of the University of Washington, Seattle, said the observatory data are game-changing in providing useful snow information for snow hydrology, climate sciences, glaciology and ecosystem studies. "Snow controls high-elevation streamflow and ecosystems, but we've historically had to guess how much snow fell and where it was stored," Lundquist said. "With these data, we can improve how we model mountain systems and predictions of how those systems will change in time. It's pretty amazing that we can both forecast for Hetch Hetchy and also drill down to one small basin affecting a meadow and see details that match photos taken on the ground. To me, the Airborne Snow Observatory snow maps are cooler than pictures from Mars."


"The Airborne Snow Observatory is an innovative use of NASA advanced sensor research applied to one of the top challenges our nation and our planet face: freshwater management and practical water management information needs," said Brad Doorn, program manager in Applied Sciences at NASA Headquarters in Washington. "The observatory is also advancing our scientific understanding of Earth processes and how we can better monitor them in the future, from both air and space."


JPL is a division of the California Institute of Technology in Pasadena. For more information on the Airborne Snow Observatory, visit: http://aso.jpl.nasa.gov/ .

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.Buis@jpl.nasa.gov


2013-357
Posted by Nelio Inacio at 5:05 PM 0 comments
Labels: , ,

NASA's Juno Gives Starship-Like View of Earth Flyby

NASA's Juno Gives Starship-Like View of Earth Flyby:

This cosmic pirouette of Earth and our moon was captured by the Juno spacecraft as it flew by Earth on Oct. 9, 2013.
This cosmic pirouette of Earth and our moon was captured by the Juno spacecraft as it flew by Earth on Oct. 9, 2013.
Image Credit: NASA/JPL-Caltech
› Larger image | 'HI' to Juno in Morse Code


December 10, 2013

When NASA's Juno spacecraft flew past Earth on Oct. 9, 2013, it received a boost in speed of more than 8,800 mph (about 3.9 kilometers per second), which set it on course for a July 4, 2016, rendezvous with Jupiter, the largest planet in our solar system. One of Juno's sensors, a special kind of camera optimized to track faint stars, also had a unique view of the Earth-moon system. The result was an intriguing, low-resolution glimpse of what our world would look like to a visitor from afar.


"If Captain Kirk of the USS Enterprise said, 'Take us home, Scotty,' this is what the crew would see," said Scott Bolton, Juno principal investigator at the Southwest Research Institute, San Antonio. "In the movie, you ride aboard Juno as it approaches Earth and then soars off into the blackness of space. No previous view of our world has ever captured the heavenly waltz of Earth and moon."


The Juno Earth flyby movie is available at: http://www.youtube.com/watch?v=_CzBlSXgzqI&feature=youtu.be . The music accompaniment is an original score by Vangelis.


The cameras that took the images for the movie are located near the pointed tip of one of the spacecraft's three solar-array arms. They are part of Juno's Magnetic Field Investigation (MAG) and are normally used to determine the orientation of the magnetic sensors. These cameras look away from the sunlit side of the solar array, so as the spacecraft approached, the system's four cameras pointed toward Earth. Earth and the moon came into view when Juno was about 600,000 miles (966,000 kilometers) away -- about three times the Earth-moon separation.


During the flyby, timing was everything. Juno was traveling about twice as fast as a typical satellite, and the spacecraft itself was spinning at 2 rpm. To assemble a movie that wouldn't make viewers dizzy, the star tracker had to capture a frame each time the camera was facing Earth at exactly the right instant. The frames were sent to Earth, where they were processed into video format.


"Everything we humans are and everything we do is represented in that view," said the star tracker's designer, John Jørgensen of the Danish Technical University, near Copenhagen.


Also during the flyby, Juno's Waves instrument, which is tasked with measuring radio and plasma waves in Jupiter's magnetosphere, recorded amateur radio signals. This was part of a public outreach effort involving ham radio operators from around the world. They were invited to say "HI" to Juno by coordinating radio transmissions that carried the same Morse-coded message. Operators from every continent, including Antarctica, participated. The results can be seen in this video clip: http://www.jpl.nasa.gov/video/?id=1263 . A four-minute video depicting the efforts of a few of the amateur radio operators who participated in the event can be seen at: http://www.jpl.nasa.gov/video/?id=1262


"With the Earth flyby completed, Juno is now on course for arrival at Jupiter on July 4, 2016," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif.


The Juno spacecraft was launched from Kennedy Space Center in Florida on August 5, 2011. Juno's launch vehicle was capable of giving the spacecraft only enough energy to reach the asteroid belt, at which point the sun's gravity pulled it back toward the inner solar system. Mission planners designed the swing by Earth as a gravity assist to increase the spacecraft's speed relative to the sun, so that it could reach Jupiter. (The spacecraft's speed relative to Earth before and after the flyby is unchanged.)


After Juno arrives and enters into orbit around Jupiter in 2016, the spacecraft will circle the planet 33 times, from pole to pole, and use its collection of science instruments to probe beneath the gas giant's obscuring cloud cover. Scientists will learn about Jupiter's origins, internal structure, atmosphere and magnetosphere.


Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief from his wife, but the goddess Juno used her special powers to peer through the clouds and reveal Jupiter's true nature.


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of the California Institute of Technology in Pasadena.


More information about Juno is online at:
http://www.nasa.gov/juno and http://missionjuno.swri.edu

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

Stephen.e.cole@nasa.gov


2013-360
Posted by Nelio Inacio at 5:04 PM 0 comments
Labels: , ,

Clay-Like Minerals Found on Icy Crust of Europa

Clay-Like Minerals Found on Icy Crust of Europa:

This image, using data from NASA's Galileo mission, shows the first detection of clay-like minerals on the surface of Jupiter's moon Europa
This image, using data from NASA's Galileo mission, shows the first detection of clay-like minerals on the surface of Jupiter's moon Europa. Image credit: NASA/JPL-Caltech/SETI
› Full image and caption


December 11, 2013

A new analysis of data from NASA's Galileo mission has revealed clay-type minerals at the surface of Jupiter's icy moon Europa that appear to have been delivered by a spectacular collision with an asteroid or comet. This is the first time such minerals have been detected on Europa's surface. The types of space rocks that deliver such minerals typically also often carry organic materials.


"Organic materials, which are important building blocks for life, are often found in comets and primitive asteroids," said Jim Shirley, a research scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Shirley is giving a talk on this topic at the American Geophysical Union meeting in San Francisco on Friday, Dec. 13. "Finding the rocky residues of this comet crash on Europa's surface may open up a new chapter in the story of the search for life on Europa," he said.


Many scientists believe Europa is the best location in our solar system to find existing life. It has a subsurface ocean in contact with rock, an icy surface that mixes with the ocean below, salts on the surface that create an energy gradient, and a source of heat (the flexing that occurs as it gets stretched and squeezed by Jupiter's gravity). Those conditions were likely in place shortly after Europa first coalesced in our solar system.


Scientists have also long thought there must be organic materials at Europa, too, though they have yet to detect them directly. One theory is that organic material could have arrived by comet or asteroid impacts, and this new finding supports that idea.


Shirley and colleagues, funded by a NASA Outer Planets Research grant, were able to see the clay-type minerals called phyllosilicates in near-infrared images from Galileo taken in 1998. Those images are low resolution by today's standards, and Shirley's group is applying a new technique for pulling a stronger signal for these materials out of the noisy picture. The phyllosilicates appear in a broken ring about 25 miles (40 kilometers) wide, which is about 75 miles (120 kilometers) away from the center of a 20-mile-diameter (30 kilometers) central crater site.


The leading explanation for this pattern is the splash back of material ejected when a comet or asteroid hits the surface at an angle of 45 degrees or more from the vertical direction. A shallow angle would allow some of the space rock's original material to fall back to the surface. A more head-on collision would likely have vaporized it or driven that space rock's materials below the surface. It is hard to see how phyllosilicates from Europa's interior could make it to the surface, due to Europa's icy crust, which scientists think may be up to 60 miles (100 kilometers) thick in some areas.


Therefore, the best explanation is that the materials came from an asteroid or comet. If the body was an asteroid, it was likely about 3,600 feet (1,100 meters) in diameter. If the body was a comet, it was likely about 5,600 feet (1,700 meters) in diameter. It would have been nearly the same size as the comet ISON before it passed around the sun a few weeks ago.


"Understanding Europa's composition is key to deciphering its history and its potential habitability," said Bob Pappalardo of JPL, the pre-project scientist for a proposed mission to Europa. "It will take a future spacecraft mission to Europa to pin down the specifics of its chemistry and the implications for this moon hosting life."


For more information about Europa, visit: http://solarsystem.nasa.gov/europa/home.cfm .


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

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


2013-362
Posted by Nelio Inacio at 5:03 PM 0 comments
Labels: , ,
Subscribe to: Posts (Atom)