Tuesday, July 22, 2014

'Witch Head' Brews Baby Stars

'Witch Head' Brews Baby Stars:

An infrared portrait of the Witch Head nebula from NASA's Wide-field Infrared Survey Explorer
An infrared portrait of the Witch Head nebula from NASA's Wide-field Infrared Survey Explorer, or WISE, shows billowy clouds where new stars are brewing. Image credit: NASA/JPL-Caltech
› Larger image

October 30, 2013

A witch appears to be screaming out into space in this new image from NASA's Wide-Field Infrared Survey Explorer, or WISE. The infrared portrait shows the Witch Head nebula, named after its resemblance to the profile of a wicked witch. Astronomers say the billowy clouds of the nebula, where baby stars are brewing, are being lit up by massive stars. Dust in the cloud is being hit with starlight, causing it to glow with infrared light, which was picked up by WISE's detectors.


The Witch Head nebula is estimated to be hundreds of light-years away in the Orion constellation, just off the famous hunter's knee.


WISE was recently "awakened" to hunt for asteroids in a program called NEOWISE. The reactivation came after the spacecraft was put into hibernation in 2011, when it completed two full scans of the sky, as planned.

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-317
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Galaxy Growth Examined Like Rings of a Tree

Galaxy Growth Examined Like Rings of a Tree:

Galaxies Grow from Inside Out
New evidence from NASA's Wide-field Infrared Survey Explorer (WISE) and Galaxy Evolution Explorer (GALEX) missions provide support for the "inside-out" theory of galaxy evolution, which holds that star formation starts at the core of the galaxy and spreads outward. Image credit: NASA/JPL-Caltech
› Full image and caption

October 31, 2013

-- Like tree rings, inner and outer portions of a galaxy's disk are a historical record

-- Two NASA missions find evidence that star formation bursts started in galaxy centers and spread outward

-- Unexplained ultraviolet light might come from a late phase in the lives of older stars


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Watching a tree grow might be more frustrating than waiting for a pot to boil, but luckily for biologists, there are tree rings. Beginning at a tree trunk's dense core and moving out to the soft bark, the passage of time is marked by concentric rings, revealing chapters of the tree's history.


Galaxies outlive trees by billions of years, making their growth impossible to see. But like biologists, astronomers can read the rings in a galaxy's disk to unravel its past. Using data from NASA's Wide-field Infrared Survey Explorer (WISE) and Galaxy Evolution Explorer (GALEX), scientists have acquired more evidence for the "inside-out" theory of galaxy growth, showing that bursts of star formation in central regions were followed one to two billion years later by star birth in the outer fringes.


"Initially, a rapid star-forming period formed the mass at the center of these galaxies, followed later by a star-forming phase in the outer regions. Eventually, the galaxies stop making stars and become quiescent," said Sara Petty of Virginia Tech, Blacksburg, Va., lead author of a paper appearing in the October 2013 issue of the Astronomical Journal. "This later star-forming phase could have been caused by minor mergers with gas-rich neighbors, which provide the fuel for new stars."


The discovery may also solve a mystery of elderly galaxies. The galaxies in the study, known as "red and dead" for their red color and lack of new star births, have a surprising amount of ultraviolet light emanating from the outer regions. Often, ultraviolet light is generated by hot, young stars, but these galaxies were considered too old to host such a young population.


The solution to the puzzle is likely hot, old stars. Petty and colleagues used a new multi-wavelength approach to show that the unexplained ultraviolet light appears to be coming from a late phase in the lives of older stars, when they blow off their outer layers and heat up.


GALEX and WISE turned out to be the ideal duo for the study. GALEX was sensitive to the ultraviolet light, whereas WISE sees the infrared light coming from older stars. GALEX is no longer operating, but WISE was recently reactivated to hunt asteroids, a project called NEOWISE (see http://www.jpl.nasa.gov/news/news.php?release=2013-257 ). Both telescopes have large fields of view, allowing them to easily capture images of entire galaxies.


"The synergy between GALEX and WISE produces a very sensitive measurement of where the hot, older stars reside in these red-and-dead galaxies," said Don Neill, co-author of the paper from the California Institute of Technology, Pasadena. "This allows us to map the progress of star formation within each galaxy."


Ned Wright of UCLA, a co-author of the study and the principal investigator of WISE before it was reactivated, compares the multi-wavelength range of the two telescopes to musical notes, "WISE itself covers the equivalent of a three-octave range, while WISE and GALEX together cover a seven-octave range."


The technical paper for this study is online at http://arxiv.org/abs/1307.6282 .


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages and operates the recently 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 Caltech. 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 .


Caltech led the Galaxy Evolution Explorer mission and was responsible for science operations and data analysis. JPL managed the mission and built the science instrument. The mission was developed under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. Researchers sponsored by Yonsei University in South Korea and the Centre National d'Etudes Spatiales (CNES) in France collaborated on this mission. Graphics and additional information about the Galaxy Evolution Explorer are online at http://www.nasa.gov/galex and http://www.galex.caltech.edu .


Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-318
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Black Holes Don't Make a Big Splash

Black Holes Don't Make a Big Splash:

Black Holes Make Waves in Ocean of Space-Time
Merging black holes ripple space and time in this artist's concept. Pulsar-timing arrays -- networks of the pulsing cores of dead stars -- are one strategy for detecting these ripples, or gravitational waves, thought to be generated when two supermassive black holes merge into one.

Image credit: Swinburne Astronomy Productions
› Larger image

November 06, 2013

Throughout our universe, tucked inside galaxies far, far away, giant black holes are pairing up and merging. As the massive bodies dance around each other in close embraces, they send out gravitational waves that ripple space and time themselves, even as the waves pass right through our planet Earth.


Scientists know these waves, predicted by Albert Einstein's theory of relativity, exist but have yet to directly detect one. In the race to catch the waves, one strategy -- called pulsar-timing arrays -- has reached a milestone not through detecting any gravitational waves, but in revealing new information about the frequency and strength of black hole mergers.


"We expect that many gravitational waves are passing through us all the time, and now we have a better idea of the extent of this background activity," said Sarah Burke-Spolaor, co-author of a new Science paper published Oct. 18, which describes research she contributed to while based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Burke-Spolaor is now at the California Institute of Technology in Pasadena.


Gravitational waves, if detected, would reveal more information about black holes as well as one of the four fundamental forces of nature: gravity.


The team's inability to detect any gravitational waves in the recent search actually has its own benefits, because it reveals new information about supermassive black hole mergers -- their frequency, distance from Earth and masses. One theory of black hole growth to hit the theorists' cutting room floors had stated that mergers alone are responsible for black holes gaining mass.


The results come from the Commonwealth Scientific and Industrial Research Organization's (CSIRO) Parkes radio telescope in eastern Australia. The study was jointly led by Ryan Shannon of CSIRO, and Vikram Ravi, of the University of Melbourne and CSIRO.


Pulsar-timing arrays are designed to catch the subtle gravitational waves using telescopes on the ground, and spinning stars called pulsars. Pulsars are the burnt-out cores of exploded stars that send out beams of radio waves like lighthouse beacons. The timing of the pulsars' rotation is so precise that researchers say they are akin to atomic clocks.


When gravitational waves pass through an array of multiple pulsars, 20 in the case of the new study, they set the pulsars bobbing like buoys. Researchers recording the radio waves from the pulsars can then piece together the background hum of waves.


"The gravitational waves cause the space between Earth and pulsars to stretch and squeeze," said Burke-Spolaor.


The new study used the Parkes Pulsar Timing Array, which got its start in the 1990s. According to the research team, the array, at its current sensitivity, will be able to detect a gravitational wave within 10 years.


Researchers at JPL are currently developing a similar precision pulsar-timing capability for NASA's Deep Space Network, a system of large dish antennas located around Earth that tracks and communicates with deep-space spacecraft. During gaps in the network's tracking schedules, the antennas can be used to precisely measure the timing of pulsars' radio waves. Because the Deep Space Network's antennas are distributed around the globe, they can see pulsars across the whole sky, which improves sensitivity to gravitational waves.


"Right now, the focus in the pulsar-timing array communities is to develop more sensitive technologies and to establish long-term monitoring programs of a large ensemble of the pulsars," said Walid Majid, the principal investigator of the Deep Space Network pulsar-timing program at JPL. "All the strategies for detecting gravitational waves, including LIGO [Laser Interferometer Gravitational-Wave Observatory], are complementary, since each technique is sensitive to detection of gravitational waves at very different frequencies. While some might characterize this as a race, in the end, the goal is to detect gravitational waves, which will usher in the beginning of gravitational wave astronomy. That is the real exciting part of this whole endeavor."


The ground-based LIGO observatory is based in Louisiana and Washington. It is a joint project of Caltech and the Massachusetts Institute of Technology, Cambridge, Mass., with funding from the National Science Foundation. The European Space Agency is developing the space-based LISA Pathfinder (Laser Interferometer Space Antenna), a proof-of-concept mission for a future space observatory to detect gravitational waves. LIGO, LISA and pulsar-timing arrays would all detect different frequencies of gravitational waves and thus are sensitive to various types of merger events.


A video about the new Parkes findings from Swinburne University of Technology in Melbourne, Australia, is online at: http://astronomy.swin.edu.au/production/blackhole/ .


Caltech manages JPL for NASA.

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-320
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NASA's GRAIL Mission Puts a New Face on the Moon

NASA's GRAIL Mission Puts a New Face on the Moon:

Using a precision formation-flying technique, the twin GRAIL spacecraft will map the moon's gravity field, as depicted in this artist's rendering.
Using a precision formation-flying technique, the twin GRAIL spacecraft mapped the moon's gravity field, as depicted in this artist's rendering. Image credit: NASA/JPL-Caltech
› Full image and caption

November 07, 2013

Scientists using data from the lunar-orbiting twins of NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission are gaining new insight into how the face of the moon received its rugged good looks. A report on the asymmetric distribution of lunar impact basins is published in this week's edition of the journal Science.


"Since time immemorial, humanity has looked up and wondered what made the man in the moon," said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology in Cambridge. "We know the dark splotches are large, lava-filled, impact basins that were created by asteroid impacts about four billion years ago. GRAIL data indicate that both the near side and the far side of the moon were bombarded by similarly large impactors, but they reacted to them much differently."


Understanding lunar impact basins has been hampered by the simple fact that there is a lack of consensus on their size. Most of the largest impact basins on the near side of the moon (the moon's face) have been filled with lava flows, which hide important clues about the shape of the land that could be used for determining their dimensions. The GRAIL mission measured the internal structure of the moon in unprecedented detail for nine months in 2012. With the data, GRAIL scientists have redefined the sizes of massive impact basins on the moon.


Maps of crustal thickness generated by GRAIL revealed more large impact basins on the near-side hemisphere of the moon than on the far side. How could this be if both hemispheres were, as widely believed, on the receiving end of the same number of impacts?


Scientists have long known that the temperatures of the near-side hemisphere of the moon were higher than those on the far side: the abundances of the heat producing elements uranium and thorium are higher on the near side than the far side, and as a consequence, the vast majority of volcanic eruptions occurred on the moon's near-side hemisphere.


"Impact simulations indicate that impacts into a hot, thin crust representative of the early moon's near-side hemisphere would have produced basins with as much as twice the diameter as similar impacts into cooler crust, which is indicative of early conditions on the moon's far-side hemisphere," notes lead author Katarina Miljkovic of the Institut de Physique du Globe de Paris.


The new GRAIL research is also helping redefine the concept of the late heavy bombardment, a proposed spike in the rate of crater creation by impacts about 4 billion years ago. The late heavy bombardment is based largely on the ages of large near-side impact basins that are either within, or adjacent to the dark, lava-filled basins, or lunar maria, named Oceanus Procellarum and Mare Imbrium. However, the special composition of the material on and below the surface of the near side implies that the temperatures beneath this region were not representative of the moon as a whole at the time of the late heavy bombardment. The difference in the temperature profiles would have caused scientists to overestimate the magnitude of the basin-forming impact bombardment. Work by GRAIL scientists supports the hypothesis that the size distribution of impact basins on the far-side hemisphere of the moon is a more accurate indicator of the impact history of the inner solar system than those on the near side.


Launched as GRAIL A and GRAIL B in September 2011, the probes, renamed Ebb and Flow by schoolchildren in Montana, operated in a nearly circular orbit near the poles of the moon at an altitude of about 34 miles (55 kilometers) until their mission ended in December 2012. The distance between the twin probes changed slightly as they flew over areas of greater and lesser gravity caused by visible features, such as mountains and craters, and by masses hidden beneath the lunar surface.


JPL, a division of the California Institute of Technology in Pasadena, Calif. managed GRAIL for NASA's Science Mission Directorate in Washington. The mission was part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. NASA's Goddard Space Flight Center, in Greenbelt, Md., manages the Lunar Reconnaissance Orbiter. Operations of the spacecraft's laser altimeter, which provided supporting data used in this investigation, is led by the Massachusetts Institute of Technology in Cambridge. Lockheed Martin Space Systems in Denver built GRAIL.


For more information about GRAIL, visit http://www.nasa.gov/grail and http://grail.nasa.gov

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


Dwayne Brown 202-358-1726

Headquarters, Washington

dwayne.c.brown@nasa.gov


Sarah McDonnell 617-253-8923

Massachusetts Institute of Technology, Cambridge

s_mcd@mit.edu / cmcall5@mit.edu


2013-322
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Study Finds Climate Link to Atmospheric-River Storms

Study Finds Climate Link to Atmospheric-River Storms:

Animation of the atmospheric-river event.
Animation of the atmospheric-river event. This animation shows an atmospheric river event over Dec. 18-20, 2010. High-altitude winds pull large amounts of water vapor (yellow and orange) from the tropical ocean near Hawaii and carry it straight to California.
Image Credit:
Anthony Wimmers and Chris Velden, University of Wisconsin-CI
› Larger image

November 08, 2013

PASADENA, Calif. - A new NASA-led study of atmospheric-river storms from the Pacific Ocean may help scientists better predict major winter snowfalls that hit West Coast mountains and lead to heavy spring runoff and sometimes flooding.


Atmospheric rivers -- short-lived wind tunnels that carry water vapor from the tropical oceans to mid-latitude land areas -- are prolific producers of rain and snow on California's Sierra Nevada mountains. The finding, published in the journal Water Resources Research, has major implications for water management in the West, where Sierra runoff is used for drinking water, agriculture and hydropower.


The research team studied how two of the most common atmospheric circulation patterns in the Northern Hemisphere interact with atmospheric rivers. They found when those patterns line up in a certain way, they create a virtual freeway that leads the moisture-laden winds straight to the Sierras.


Bin Guan of the Joint Institute for Regional Earth System Science and Engineering, a collaboration between NASA's Jet Propulsion Laboratory in Pasadena, Calif., and UCLA, led a team of scientists from NASA, UCLA and the National Oceanic and Atmospheric Administration (NOAA) on this research.


An atmospheric river is a narrow stream of wind, about a mile (1.6 kilometers) high and sometimes of hurricane strength. Crossing the warm tropical Pacific in a few days, it becomes laden with water vapor. A moderate-sized atmospheric river carries as much water as the Mississippi River dumps into the Gulf of Mexico in an average week. When the river comes ashore and stalls over higher terrain, the water falls as snow or rain.


"Atmospheric rivers are the bridge between climate and West Coast snow," said Guan. "If scientists can predict these atmospheric patterns with reasonable lead times, we'll have a better understanding of water availability and flooding in the region." The benefit of improving flood prediction alone would be significant. A single California atmospheric-river storm in 1999 caused 15 deaths and $570 million in damage.


Guan's team used data from the JPL-developed Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite, along with NOAA satellite data and snowpack data from the California Department of Water Resources. They looked at the extremely snowy winter of 2010-2011, when 20 atmospheric rivers made landfall.


The team compared the dates of these events with the phases of the Arctic Oscillation (AO) and the Pacific/North American teleconnection (PNA). These large-scale weather patterns wax and wane, stretching thousands of miles across the atmosphere and shaping the climate of the mid-latitudes, somewhat as the better-known El Niño and La Niña patterns do in the tropical Pacific.


Each pattern affects a different part of the Northern Hemisphere by seesawing between phases of lower-than-average and higher-than-average air pressure over various parts of the globe. For example, the negative phase of the AO is associated with higher pressure in the Arctic and lower pressure in the surrounding lower latitudes. In the positive phase, those highs and lows are reversed.


The phases of each pattern change irregularly and at varying intervals. The researchers charted these phases throughout the winter of 2010-2011. During 15 of the winter's 20 atmospheric river occurrences, both patterns were in the negative phase. The team then looked at the period 1998-2011 and found a similar correspondence: more atmospheric rivers occurred when both patterns were negative.


According to Guan, in the double-negative periods, the high- and low-pressure systems associated with that phase in each pattern mesh to create a lingering atmospheric low-pressure system just northwest of California. That low directs the atmospheric river fire hose straight toward the Sierra Nevadas.


Guan points out that the double-negative phase correlation is rare.


"I looked at 50 years of atmospheric data. Only five months had those phases of the PNA and AO occurring together for more than 15 days of the month," he said.


AIRS was built and is managed by JPL for NASA's Science Mission Directorate in Washington. Aqua is managed by NASA's Goddard Space Flight Center, Greenbelt, Md. JPL is a division of the California Institute of Technology in Pasadena.


For more information on AIRS, visit: http://airs.jpl.nasa.gov .

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.Buis@jpl.nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

Stephen.e.cole@nasa.gov


Written by Carol Rasmussen


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Prolific NASA Mars Orbiter Passes Big Data Milestone

Prolific NASA Mars Orbiter Passes Big Data Milestone:

Artist concept of Mars Reconnaissance Orbiter. Image credit: NASA/JPL
Artist concept of Mars Reconnaissance Orbiter. Image credit: NASA/JPL
› Full image and caption

November 08, 2013

NASA's Mars Reconnaissance Orbiter, which has overhauled understanding of the Red Planet since 2006, has passed 200 terabits in the amount of science data returned. The data returned by the mission alone is more than three times the total data returned via NASA's Deep Space Network for all the other missions managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., over the past 10 years.


While the 200 terabits number includes all the data this orbiter has relayed to Earth from robots on the surface of Mars, about 99.9 percent of the volume has come from the six science instruments aboard Mars Reconnaissance Orbiter. The 200 terabits are equivalent to the data volume in three nonstop months of high-definition video. The number does not include the engineering data that specialists operating the orbiter from JPL and Lockheed Martin Space Systems, Denver, use for monitoring its health and performance.


The spacecraft pours data Earthward using a dish antenna 10 feet (3 meters) across and a transmitter powered by 215 square feet (20 square meters) of solar cells. Multiple sessions each day with giant dish antennas of the Deep Space Network in California, Spain and Australia enable Earth to receive such a torrent of data from the orbiter.


"The sheer volume is impressive, but of course what's most important is what we are learning about our neighboring planet," said JPL's Rich Zurek, the project scientist for the Mars Reconnaissance Orbiter.


The orbiter's instruments have examined Mars from subsurface to atmosphere in unprecedented detail. One instrument has provided images revealing features as small as a desk in surface areas equivalent to one-third of the United States (1.92 percent of Mars' surface). Another has covered areas equivalent to about 82 percent of Earth's land area (83.6 percent of Mars' surface), with resolution showing features smaller than a tennis court. These cameras have viewed many areas repeatedly, providing three-dimensional information from stereo and revealing several types of landscape changes over time. Other instruments identify surface minerals, probe underground layers, examine cross-sections of the atmosphere and track weather globally.


"The mission has taught us about three very different periods of Mars history," Zurek said.


Its observations of the heavily cratered terrains of Mars, the oldest on the planet, show that different types of ancient watery environments formed water-related minerals. Some of these would have been more favorable for life than others. In more recent times, water appears to have cycled as a gas between polar ice deposits and lower-latitude deposits of ice and snow. Extensive layering in ice or rock probably took hundreds of thousands to millions of years to form. The present climate is also dynamic, with volatile carbon dioxide and, possibly, flows of briny water forming dark streaks that are observed to appear in the warmest seasons and places and fade in colder weather.


"Mars Reconnaissance Orbiter has shown that Mars is still an active planet, with changes such as new craters, avalanches and dust storms," Zurek said. "Mars is a partially frozen world, but not frozen in time."


Each of the 200 trillion bits of science data from the orbiter has followed a complex path, aided by sophisticated software to make it feasible for a small team to handle tens of billions of new bits daily and get the data products to the appropriate scientists.


Data gathered by the orbiter's instruments and relayed from rovers are recorded onto the orbiter's central memory. Each orbit around Mars takes the spacecraft about two hours. For part of each orbit, Mars itself usually blocks the communication path to Earth. When Earth is in view, a Deep Space Network antenna on whichever part of Earth is turned toward Mars at that hour can be listening. Complex preparations coordinate scheduling the use of the network's antennas by all deep-space missions -- 32 of them this month. Mars Reconnaissance Orbiter typically gets several sessions every day.


"The Deep Space Network collects the incoming data into 30-minute chunks," said Mars Reconnaissance Orbiter software engineer Bryan Allen, of JPL. "At that point, it doesn't matter which products are in it -- just a big pile of bits."


The chunks of mixed data from the antenna stations in California, Spain and Australia come to JPL, where software sorts it into specific products, such as an image from a camera, measurements from a scan of the atmosphere, radar readings from the subsurface sounder, or data from a rover. Another process at JPL determines which products to send where -- such as to a mineral-mapping team in Maryland, a camera team in Arizona, a radar team in Italy. On a typical recent day, the system sorted 58 billion bits from Mars Reconnaissance Orbiter into 303 data products.


The Mars Reconnaissance Orbiter mission met all its science goals in a two-year primary science phase ending in 2008. Three extensions, the latest beginning in 2012, have added to the science returns. The longevity of this mission and of NASA's even longer-lived Mars Odyssey orbiter, which has been studying Mars since 2002, have 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 and Mars Odyssey projects for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems built both orbiters and collaborates with JPL to operate them. JPL operates the Deep Space Network for NASA's Human Exploration and Operations Mission Directorate, Washington. For more information about the Mars Reconnaissance Orbiter, visit http://www.nasa.gov/mro and http://mars.jpl.nasa.gov/mro/ .

DC Agle/Guy Webster 818-393-9011/354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov / guy.webster@jpl.nasa.gov

2013-324
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Spitzer and ALMA Reveal a Star's Bubbly Birth

Spitzer and ALMA Reveal a Star's Bubbly Birth:

Bubbly Newborn Star
Combined observations from NASA's Spitzer Space Telescope and the newly completed Atacama Large Millimeter/submillimeter Array (ALMA) in Chile have revealed the throes of stellar birth, as never before, in the well-studied object known as HH 46/47. Image credit: NASA/JPL-Caltech/ALMA
› Full image and caption

November 11, 2013

It's a bouncing baby . . . star! Combined observations from NASA's Spitzer Space Telescope and the newly completed Atacama Large Millimeter/submillimeter Array (ALMA) in Chile have revealed the throes of stellar birth as never before in the well-studied object known as HH 46/47.


Herbig-Haro (HH) objects form when jets shot out by newborn stars collide with surrounding material, producing small, bright, nebulous regions. To our eyes, the dynamics within many HH objects are obscured by enveloping gas and dust. But the infrared and submillimeter wavelengths of light seen by Spitzer and ALMA, respectively, pierce the dark cosmic cloud around HH 46/47 to let us in on the action.


The Spitzer observations show twin supersonic jets emanating from the central star that blast away surrounding gas and set it alight into two bubbly lobes. HH 46/47 happens to sit on the edge of its enveloping cloud in such a way that the jets pass through two differing cosmic environments. The rightward jet, heading into the cloud, is plowing through a "wall" of material, while the leftward jet's path out of the cloud is relatively unobstructed, passing through less material. This orientation serves scientists well by offering a handy compare-and-contrast setup for how the outflows from a developing star interact with their surroundings.


"Young stars like our sun need to remove some of the gas collapsing in on them to become stable, and HH 46/47 is an excellent laboratory for studying this outflow process," said Alberto Noriega-Crespo, a scientist at the Infrared Processing and Analysis Center at the California Institute of Technology, Pasadena, Calif. "Thanks to Spitzer, the HH 46/47 outflow is considered one of the best examples of a jet being present with an expanding bubble-like structure."


Noriega-Crespo led the team that began studying HH 46/47 with Spitzer nearly 10 years ago when the telescope first began observing the heavens. Now, using a new image processing technique developed in the past few years, he and his colleagues have been able to render HH 46/47 in higher resolution.


Meanwhile, the fresh views of HH 46/47 by ALMA have revealed that the gas in the lobes is expanding faster than previously thought. This faster expansion has an influence on the overall amount of turbulence in the gaseous cloud that originally spawned the star. In turn, the extra turbulence could have an impact on whether and how other stars might form in this gaseous, dusty, and thus fertile, ground for star-making.


A team led by Hector Arce at Yale University, New Haven, Conn., carried out the ALMA observations and their analysis was published recently in The Astrophysical Journal.


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. 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.


The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile.

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-328
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NASA Cassini Spacecraft Provides New View of Saturn and Earth

NASA Cassini Spacecraft Provides New View of Saturn and Earth:

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

November 12, 2013

• Natural-color portrait that is first to show Saturn, its moons and rings, plus Earth, Venus and Mars


• Sweeps nearly 405,000 miles across Saturn and its inner rings


NASA has released a natural-color image of Saturn from space, the first in which Saturn, its moons and rings, and Earth, Venus and Mars, all are visible.


The new panoramic mosaic of the majestic Saturn system taken by NASA's Cassini spacecraft, which shows the view as it would be seen by human eyes, was unveiled at the Newseum in Washington on Tuesday.


Cassini's imaging team processed 141 wide-angle images to create the panorama. The image sweeps 404,880 miles (651,591 kilometers) across Saturn and its inner ring system, including all of Saturn's rings out to the E ring, which is Saturn's second outermost ring. For perspective, the distance between Earth and our moon would fit comfortably inside the span of the E ring.


"In this one magnificent view, Cassini has delivered to us a universe of marvels," said Carolyn Porco, Cassini's imaging team lead at the Space Science Institute in Boulder, Colo. "And it did so on a day people all over the world, in unison, smiled in celebration at the sheer joy of being alive on a pale blue dot."


The mosaic is part of Cassini's "Wave at Saturn" campaign, where on July 19, people for the first time had advance notice a spacecraft was taking their picture from planetary distances. NASA invited the public to celebrate by finding Saturn in their part of the sky, waving at the ringed planet and sharing pictures over the Internet.


An annotated version of the Saturn system mosaic labels points of interest. Earth is a bright blue dot to the lower right of Saturn. Venus is a bright dot to Saturn's upper left. Mars also appears, as a faint red dot, above and to the left of Venus. Seven Saturnian moons are visible, including Enceladus on the left side of the image. Zooming into the image reveals the moon and the icy plume emanating from its south pole, supplying fine, powder-sized icy particles that make up the E ring.


The E ring shines like a halo around Saturn and the inner rings. Because it is so tenuous, it is best seen with light shining from behind it, when the tiny particles are outlined with light because of the phenomenon of diffraction. Scientists who focus on Saturn's rings look for patterns in optical bonanzas like these. They use computers to increase dramatically the contrast of the images and change the color balance, for example, to see evidence for material tracing out the full orbits of the tiny moons Anthe and Methone for the first time.


"This mosaic provides a remarkable amount of high-quality data on Saturn's diffuse rings, revealing all sorts of intriguing structures we are currently trying to understand," said Matt Hedman, a Cassini participating scientist at the University of Idaho in Moscow. "The E ring in particular shows patterns that likely reflect disturbances from such diverse sources as sunlight and Enceladus' gravity."


Cassini does not attempt many images of Earth because the sun is so close to our planet that an unobstructed view would damage the spacecraft's sensitive detectors. Cassini team members looked for an opportunity when the sun would slip behind Saturn from Cassini's point of view. A good opportunity came on July 19, when Cassini was able to capture a picture of Earth and its moon, and this multi-image, backlit panorama of the Saturn system.


"With a long, intricate dance around the Saturn system, Cassini aims to study the Saturn system from as many angles as possible," said Linda Spilker, Cassini project scientist based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Beyond showing us the beauty of the Ringed Planet, data like these also improve our understanding of the history of the faint rings around Saturn and the way disks around planets form -- clues to how our own solar system formed around the sun."


Launched in 1997, Cassini has explored the Saturn system for more than nine years. NASA plans to continue the mission through 2017, with the anticipation of many more images of Saturn, its rings and moons, as well as other scientific data.


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. 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.


To view the image, visit: http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17172 .


A new version of the collage of photos shared by the public, with the Saturn system as backdrop, is available at: http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17679 .


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


Steve Mullins 720-974-5859

Space Science Institute, Boulder, Colo.

media@ciclops.org


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Curiosity Out of Safe Mode

Curiosity Out of Safe Mode:

Mars Rover Curiosity in Artist's Concept, Close-up
This artist concept features NASA's Mars Science Laboratory Curiosity rover, a mobile robot for investigating Mars' past or present ability to sustain microbial life. Image credit:
NASA/JPL-Caltech
› Full image and caption

November 12, 2013

Mars Science Laboratory Mission Status Report


NASA's Mars Science Laboratory Project received confirmation from Mars Sunday (Nov. 10) that the Curiosity rover has successfully transitioned back into nominal surface operations mode. Curiosity had been in safe mode since Nov. 7, when an unexpected software reboot (also known as a warm reset) occurred during a communications pass with the Mars Reconnaissance Orbiter. Mission science planning will resume tomorrow, and Curiosity science operations will recommence on Thursday.


"We returned to normal engineering operations," said Rajeev Joshi, a software and systems engineer for the Curiosity mission at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We are well into planning the next several days of surface operations and expect to resume our drive to Mount Sharp this week."


After analyzing the data returned by the spacecraft on Thursday evening, Nov. 7 (Pacific Time), the Curiosity operations team was able to determine the root cause. An error in existing onboard software resulted in an error in a catalog file. This caused an unexpected reset when the catalog was processed by a new version of flight software which had been installed on Thursday. The team was able to replicate the problem on ground testbeds the following day. Commands recovering the spacecraft were uplinked to the spacecraft early Sunday morning.


NASA's Mars Science Laboratory Project is using Curiosity to assess whether areas inside Gale Crater ever offered a habitable environment for microbes. JPL, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate in Washington.


More information about Curiosity is online at http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com/marscuriosity .

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


2013-330
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NASA Helps Melt Secrets of Great Lakes Ice

NASA Helps Melt Secrets of Great Lakes Ice:

colorful radar photo of Lake Superior
A color-coded image of major ice types on Lake Superior, made from a RADARSAT1 radar backscatter image using a new NASA and NOAA-developed technique. Credit: NOAA Great Lakes Environmental Research Laboratory and NASA/JPL-Caltech

› Larger image

November 13, 2013

Two scientists from NASA and NOAA have developed a new space-based technique for monitoring the ice cover of the Great Lakes that is so accurate it can identify a narrow channel of open water cut through the ice by an icebreaker -- even at night.


"In the dark, it's difficult to read a map that's right in front of you," said Son Nghiem of NASA's Jet Propulsion Laboratory, Pasadena, Calif., one of the developers of the new technique. "Yet we now have a way to use satellite radars almost 500 miles [800 kilometers] out in space to see through clouds and darkness and map ice across the Great Lakes."


Ice on the Great Lakes puts a big chill on the U.S. and Canadian economies, affecting shipping, fishing and also public safety when winter and spring flooding are caused by ice jams. It has a significant impact on the regional environment and ecological systems as well. Yet previous techniques of analyzing satellite observations of the ice sometimes misidentified ice as water and vice versa.


The new method, co-developed by Nghiem and his colleague George Leshkevich of NOAA's Great Lakes Environmental Research Laboratory, Ann Arbor, Mich., not only corrects that problem, it also gives a more accurate analysis of ice characteristics, such as whether the ice is dense or full of bubbles, and whether it has melted and refrozen.


The method uses a special dictionary that translates binary digital data from satellite radar instruments on the Canadian Space Agency's RADARSAT-1/2, the European Space Agency's European Remote Sensing Satellite 2 (ERS-2), and Envisat to identify and map different types of ice over the Great Lakes. The researchers compiled the dictionary by pairing each observed ice type to a library of unique radar signatures that were measured on the lakes using a JPL-developed advanced radar aboard a U.S. Coast Guard icebreaking ship.


Leshkevich said the method has now been transitioned to NOAA for routine use in generating ice maps across the Great Lakes. "These maps will provide important information for environmental management, ice forecasting and modeling, off-shore wind farm development, operational icebreaking activities in support of winter navigation, and science research."


The more accurate classification of ice will also be useful for scientific research into such questions as how the Great Lakes are responding to, and leading, climate change in the upper Midwest.


Results of the study were published recently in the Journal of Great Lakes Research.


For more information, visit: http://www.iaglr.org/jglr/release/39/2013.05.003_leshkevich.php .

Written by Carol Rasmussen


Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.buis@jpl.nasa.gov


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Monday, July 21, 2014

Nature Pulls a Fast One on Astronomers

Nature Pulls a Fast One on Astronomers:

Two Galaxies Masquerading as One
The edge-on spiral galaxy UGC 10288 appeared to be a single object in previous observations. However, new detailed radio data from the NRAO's Jansky Very Large Array (VLA) revealed that the large perpendicular extension of UGC 10288's halo (blue) is really a distant background galaxy with radio jets. Image credit: VLA/NASA/JPL-Caltech/SDSS/NOAO/University of Manitoba
› Full image and caption


November 14, 2013

What might look like a colossal jet shooting away from a galaxy turns out to be an illusion. New data from the National Science Foundation's Karl G. Jansky Very Large Array (VLA) reveal that two galaxies, one lying behind the other, have been masquerading as one.


In a new image highlighting the chance alignment, radio data from the VLA are blue and infrared observations from NASA's Spitzer Space Telescope and Wide-field Infrared Survey Explorer (WISE) are yellow and orange, respectively. Visible data are also shown, with starlight in purplish blue and heated gas in rose.


The closer galaxy, called UGC 10288, is located 100 million light-years away. It is spiral in shape, but from our viewpoint on Earth, we are seeing its thin edge. The farther galaxy, seen in blue, is nearly 7 billion light-years away. Two giant jets shoot away from this galaxy, one of which is seen above the plane of the closer galaxy's disk.


Earlier radio images of the two galaxies appeared as one fuzzy blob, and fooled astronomers into thinking they were looking at one galaxy. Thanks to the VLA pulling the curtain back on the disguised duo, the scientists have a unique opportunity to learn otherwise-unobtainable facts about the nearer galaxy.


"We can use the radio waves from the background galaxy, coming through the nearer one, as a way to measure the properties of the nearer galaxy," said Judith Irwin, of Queen's University, Canada, lead author of a recent paper on the findings, appearing online Nov. 15 in the Astronomical Journal.


Observations from Spitzer and WISE helped to reveal new structures above and below the plane of the closer galaxy's disk. For example, Spitzer helped confirm an arc-like feature rising more than 11,000 light-years above the disk, which was seen in the radio observations.


Irwin worked with an international team of astronomers from North America, India and Europe who are part of the "Continuum Halos in Nearby Galaxies -- an EVLA Survey" (CHANG-ES) consortium.


The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. 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 .


JPL 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 Caltech. 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


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NASA Damage Map Helps in Typhoon Disaster Response

NASA Damage Map Helps in Typhoon Disaster Response:

NASA-Generated Damage Map To Assist With Typhoon Haiyan Disaster Response
When Super Typhoon Haiyan, one of the most powerful storms ever recorded on Earth, struck the Philippines Nov. 8, 2013, it tore a wide swath of destruction across large parts of the island nation. Image Credit:
ASI/NASA/JPL-Caltech
› Full image and caption


November 13, 2013

A new, space-based map generated by scientists at NASA's Jet Propulsion Laboratory, Pasadena, Calif., in collaboration with the Italian Space Agency to assist in disaster response efforts shows the regions in the Philippines hit hardest by Super Typhoon Haiyan. The typhoon tore a wide swath of devastation across the island nation on Nov. 8, 2013.


The map, which depicts the storm's destruction, is available online at:
http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17687 .


This 27-by-33-mile (43-by-53-kilometer) map covers a region near Tacloban City, where the massive storm, one of the most powerful ever recorded on Earth, made landfall. It was made from radar imagery obtained before and after the typhoon hit. It was processed by JPL's Advanced Rapid Imaging and Analysis (ARIA) team using X-band interferometric synthetic aperture radar data from the Italian Space Agency's COSMO-SkyMed satellite constellation. The technique uses a prototype algorithm to rapidly detect surface changes caused by natural or human-produced damage.


The technique is most sensitive to detecting destruction of the human-made environment. In the image, damage detected by radar is shown as an overlay on a Google Earth image. Areas in red reflect the heaviest damage to cities and towns in the storm's path. The estimated intensity of damage is proportional to the opacity of the red. When the radar observes areas that have little to no destruction, its image pixels are transparent. The satellite data used to generate the map span the time frame from Aug. 19 to Nov. 11, 2013. Each pixel in the damage map measures approximately 33 yards (30 meters) across.


ARIA is a JPL- and NASA-funded project being developed by JPL and the California Institute of Technology, Pasadena, Calif. It is building an automated system for providing rapid and reliable GPS and satellite data to support the local, national and international hazard monitoring and response communities. Using space-based imagery of disasters, ARIA data products can provide rapid assessments of the geographic region affected by a disaster, as well as detailed imaging of the locations where damage occurred.


NASA is making the data publicly available for agencies that might be responding to the event through the U.S. Geological Survey's Earth Resources Observation and Science (EROS) Data Center's Hazards Data Distribution System, as well as through NASA's ARIA website.


The ARIA team began developing and evaluating this technique using case studies from the magnitude 6.3 earthquake in Christchurch, New Zealand, in February 2011 to detect building damage, landslides and liquefaction. Following the magnitude 9.0 earthquake in Tohoku, Japan, in March 2011, the team used the technique to assess tsunami damage, as well as ground deformation from high-rate GPS network and imaging radar satellites. Those ground-deformation data were downloaded more than 1,400 times within the first two days they were available. Following last year's Hurricane Sandy, the team produced damage maps that were delivered to the International Charter 11 days after landfall and subsequently validated with crowdsourcing with the assistance of the GISCorps.


The ARIA team continues to improve its response time for generating products -- the Haiyan satellite data were available three days after landfall and were processed within 11 hours of data acquisition. The improved response time has been aided by NASA's recent joint collaboration with the Italian Space Agency, which operates four identical radar satellites.


For more information about ARIA, visit: http://aria.jpl.nasa.gov .


Caltech manages JPL for NASA.

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.buis@jpl.nasa.gov


2013-333
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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
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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
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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


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