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Thursday, June 28, 2012

NASA's Next Mars Rover to Face 7 Minutes of Terror

NASA's Next Mars Rover to Face 7 Minutes of Terror

It may be described as reasoned - even genius - engineering. But even the engineers who designed it agree it looks crazy. Six vehicle configurations, 76 pyrotechnic devices, 500,000 lines of code, zero margin for error. What exactly will it take to land NASA's next Mars rover, Curiosity, on the surface of Mars on Aug. 5? The latest video from NASA's Jet Propulsion Laboratory breaks down all "7 minutes of terror."

Watch it now at http://bit.ly/edlemail.

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Cassini Finds Likely Subsurface Ocean on Saturn Moon

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.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

News release: 2012-190 June 28, 2012

Cassini Finds Likely Subsurface Ocean on Saturn Moon

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-190&cid=release_2012-190

PASADENA, Calif. -- Data from NASA's Cassini spacecraft have revealed Saturn's moon Titan
likely harbors a layer of liquid water under its ice shell.

Researchers saw a large amount of squeezing and stretching as the moon orbited Saturn. They
deduced that if Titan were composed entirely of stiff rock, the gravitational attraction of Saturn
would cause bulges, or solid "tides," on the moon only 3 feet (1 meter) in height. Spacecraft data
show Saturn creates solid tides approximately 30 feet (10 meters) in height, which suggests Titan is
not made entirely of solid rocky material. The finding appears in today's edition of the journal
Science.

"Cassini's detection of large tides on Titan leads to the almost inescapable conclusion that there is a
hidden ocean at depth," said Luciano Iess, the paper's lead author and a Cassini team member at the
Sapienza University of Rome, Italy. "The search for water is an important goal in solar system
exploration, and now we've spotted another place where it is abundant."

Titan takes only 16 days to orbit Saturn, and scientists were able to study the moon's shape at
different parts of its orbit. Because Titan is not spherical, but slightly elongated like a football, its
long axis grew when it was closer to Saturn. Eight days later, when Titan was farther from Saturn, it
became less elongated and more nearly round. Cassini measured the gravitational effect of that
squeeze and pull.

Scientists were not sure Cassini would be able to detect the bulges caused by Saturn's pull on Titan.
By studying six close flybys of Titan from Feb. 27, 2006, to Feb. 18, 2011, researchers were able to
determine the moon's internal structure by measuring variations in the gravitational pull of Titan
using data returned to NASA's Deep Space Network (DSN).

"We were making ultrasensitive measurements, and thankfully Cassini and the DSN were able to
maintain a very stable link," said Sami Asmar, a Cassini team member at NASA's Jet Propulsion
Laboratory in Pasadena, Calif. "The tides on Titan pulled up by Saturn aren't huge compared to the
pull the biggest planet, Jupiter, has on some of its moons. But, short of being able to drill on Titan's
surface, the gravity measurements provide the best data we have of Titan's internal structure."

An ocean layer does not have to be huge or deep to create these tides. A liquid layer between the
external, deformable shell and a solid mantle would enable Titan to bulge and compress as it orbits
Saturn. Because Titan's surface is mostly made of water ice, which is abundant in moons of the outer
solar system, scientists infer Titan's ocean is likely mostly liquid water.

On Earth, tides result from the gravitational attraction of the moon and sun pulling on our surface
oceans. In the open oceans, those can be as high as two feet (60 centimeters). While water is easier to
move, the gravitational pulling by the sun and moon also causes Earth's crust to bulge in solid tides of
about 20 inches (50 centimeters).

The presence of a subsurface layer of liquid water at Titan is not itself an indicator for life. Scientists
think life is more likely to arise when liquid water is in contact with rock, and these measurements
cannot tell whether the ocean bottom is made up of rock or ice. The results have a bigger implication
for the mystery of methane replenishment on Titan.

"The presence of a liquid water layer in Titan is important because we want to understand how
methane is stored in Titan's interior and how it may outgas to the surface," said Jonathan Lunine, a
Cassini team member at Cornell University, Ithaca, N.Y. "This is important because everything that
is unique about Titan derives from the presence of abundant methane, yet the methane in the
atmosphere is unstable and will be destroyed on geologically short timescales."

A liquid water ocean, "salted" with ammonia, could produce buoyant ammonia-water liquids that
bubble up through the crust and liberate methane from the ice. Such an ocean could serve also as a
deep reservoir for storing methane.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the
Italian Space Agency. The mission is managed by JPL for NASA's Science Mission Directorate in
Washington. DSN, also managed by JPL, is an international network of antennas that supports
interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of
the solar system and the universe. The network also supports selected Earth-orbiting missions.
Cassini's radio science team is based at Wellesley College in Massachusetts. JPL is a division of the
California Institute of Technology in Pasadena.

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

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Tuesday, June 26, 2012

Astronomers Spot Rare Arc From Hefty Galaxy Cluster

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. PHONE 818-354-5011
http://www.jpl.nasa.gov

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

Donna Weaver / Ray Villard 410-338-4493 / 338-4514
Space Telescope Science Institute, Baltimore, Md.
dweaver@stsci.edu / villard@stsci.edu

News release: 2012-187 June 26, 2012

Astronomers Spot Rare Arc From Hefty Galaxy Cluster

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-187&cid=release_2012-187

PASADENA, Calif. -- Seeing is believing, except when you don't believe what you see.
Astronomers using NASA's Hubble Space Telescope have found a puzzling arc of light behind
an extremely massive cluster of galaxies residing 10 billion light-years away. The galactic
grouping, discovered by NASA's Spitzer Space Telescope, was observed as it existed when the
universe was roughly a quarter of its current age of 13.7 billion years.

The giant arc is the stretched shape of a more distant galaxy whose light is distorted by the
monster cluster's powerful gravity, an effect called gravitational lensing. The trouble is, the arc
shouldn't exist.

"When I first saw it, I kept staring at it, thinking it would go away," said study leader Anthony
Gonzalez of the University of Florida in Gainesville, whose team includes researchers from
NASA's Jet Propulsion Laboratory, Pasadena, Calif. "According to a statistical analysis, arcs
should be extremely rare at that distance. At that early epoch, the expectation is that there are not
enough galaxies behind the cluster bright enough to be seen, even if they were 'lensed,' or
distorted by the cluster. The other problem is that galaxy clusters become less massive the further
back in time you go. So it's more difficult to find a cluster with enough mass to be a good lens
for gravitationally bending the light from a distant galaxy."

Galaxy clusters are collections of hundreds to thousands of galaxies bound together by gravity.
They are the most massive structures in our universe. Astronomers frequently study galaxy
clusters to look for faraway, magnified galaxies behind them that would otherwise be too dim to
see with telescopes. Many such gravitationally lensed galaxies have been found behind galaxy
clusters closer to Earth.

The surprise in this Hubble observation is spotting a galaxy lensed by an extremely distant
cluster. Dubbed IDCS J1426.5+3508, the cluster is the most massive found at that epoch,
weighing as much as 500 trillion suns. It is 5 to 10 times larger than other clusters found at such
an early time in the history of the universe. The team spotted the cluster in a search using
NASA's Spitzer Space Telescope in combination with archival optical images taken as part of
the National Optical Astronomy Observatory's Deep Wide Field Survey at the Kitt Peak National
Observatory, Tucson, Ariz. The combined images allowed them to see the cluster as a grouping
of very red galaxies, indicating they are far away.

This unique system constitutes the most distant cluster known to "host" a giant gravitationally
lensed arc. Finding this ancient gravitational arc may yield insight into how, during the first
moments after the Big Bang, conditions were set up for the growth of hefty clusters in the early
universe.

The arc was spotted in optical images of the cluster taken in 2010 by Hubble's Advanced Camera
for Surveys. The infrared capabilities of Hubble's Wide Field Camera 3 helped provide a precise
distance, confirming it to be one of the farthest clusters yet discovered.

Once the astronomers determined the cluster's distance, they used Hubble, the Combined Array
for Research in Millimeter-wave Astronomy (CARMA) radio telescope, and NASA's Chandra
X-ray Observatory to independently show that the galactic grouping is extremely massive.

"The chance of finding such a gigantic cluster so early in the universe was less than one percent
in the small area we surveyed," said team member Mark Brodwin of the University of Missouri-
Kansas City. "It shares an evolutionary path with some of the most massive clusters we see
today, including the Coma cluster and the recently discovered El Gordo cluster."

An analysis of the arc revealed that the lensed object is a star-forming galaxy that existed 10
billion to 13 billion years ago. The team hopes to use Hubble again to obtain a more accurate
distance to the lensed galaxy.

The team's results are described in three papers, which will appear online today and will be
published in the July 10, 2012 issue of The Astrophysical Journal. Gonzalez is the first author on
one of the papers; Brodwin, on another; and Adam Stanford of the University of California at
Davis, on the third. Daniel Stern and Peter Eisenhardt of JPL are co-authors on all three papers.

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

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Monday, June 25, 2012

Cassini Shows Why Jet Streams Cross-Cut Saturn

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov

Joe Mason 720-974-5859
Space Science Institute, Boulder, Colo.
media@ciclops.org

Bill Steigerwald/Nancy Neal Jones 301-286-5017/6-0039
Goddard Space Flight Center, Greenbelt, Md.
william.a.steigerwald@nasa.gov / nancy.n.jones@nasa.gov

News feature: 2012-186 June 25, 2012

Cassini Shows Why Jet Streams Cross-Cut Saturn

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-186&cid=release_2012-186

Turbulent jet streams, regions where winds blow faster than in other places, churn east and west
across Saturn. Scientists have been trying to understand for years the mechanism that drives these
wavy structures in Saturn's atmosphere and the source from which the jets derive their energy.

In a new study appearing in the June edition of the journal Icarus, scientists used images collected
over several years by NASA's Cassini spacecraft to discover that the heat from within the planet
powers the jet streams. Condensation of water from Saturn's internal heating led to temperature
differences in the atmosphere. The temperature differences created eddies, or disturbances that move
air back and forth at the same latitude, and those eddies, in turn, accelerated the jet streams like
rotating gears driving a conveyor belt.

A competing theory had assumed that the energy for the temperature differences came from the sun.
That is how it works in the Earth's atmosphere.

"We know the atmospheres of planets such as Saturn and Jupiter can get their energy from only two
places: the sun or the internal heating. The challenge has been coming up with ways to use the data
so that we can tell the difference," said Tony Del Genio of NASA's Goddard Institute for Space
Studies, N.Y., the lead author of the paper and a member of the Cassini imaging team.

The new study was possible in part because Cassini has been in orbit around Saturn long enough to
obtain the large number of observations required to see subtle patterns emerge from the day-to-day
variations in weather. "Understanding what drives the meteorology on Saturn, and in general on
gaseous planets, has been one of our cardinal goals since the inception of the Cassini mission," said
Carolyn Porco, imaging team lead, based at the Space Science Institute, Boulder, Colo. "It is very
gratifying to see that we're finally coming to understand those atmospheric processes that make Earth
similar to, and also different from, other planets."

Rather than having a thin atmosphere and solid-and-liquid surface like Earth, Saturn is a gas giant
whose deep atmosphere is layered with multiple cloud decks at high altitudes. A series of jet streams
slice across the face of Saturn visible to the human eye and also at altitudes detectable to the near-
infrared filters of Cassini's cameras. While most blow eastward, some blow westward. Jet streams
occur on Saturn in places where the temperature varies significantly from one latitude to another.

Thanks to the filters on Cassini's cameras, which can see near-infrared light reflected to space,
scientists now have observed the Saturn jet stream process for the first time at two different, low
altitudes. One filtered view shows the upper part of the troposphere, a high layer of the atmosphere
where Cassini sees thick, high-altitude hazes and where heating by the sun is strong. Views through
another filter capture images deeper down, at the tops of ammonia ice clouds, where solar heating is
weak but closer to where weather originates. This is where water condenses and makes clouds and
rain.

In the new study, which is a follow-up to results published in 2007, the authors used automated cloud
tracking software to analyze the movements and speeds of clouds seen in hundreds of Cassini images
from 2005 through 2012.

"With our improved tracking algorithm, we've been able to extract nearly 120,000 wind vectors from
560 images, giving us an unprecedented picture of Saturn's wind flow at two independent altitudes on
a global scale," said co-author and imaging team associate John Barbara, also at the Goddard Institute
for Space Studies. The team's findings provide an observational test for existing models that
scientists use to study the mechanisms that power the jet streams.

By seeing for the first time how these eddies accelerate the jet streams at two different altitudes,
scientists found the eddies were weak at the higher altitudes where previous researchers had found
that most of the sun's heating occurs. The eddies were stronger deeper in the atmosphere. Thus, the
authors could discount heating from the sun and infer instead that the internal heat of the planet is
ultimately driving the acceleration of the jet streams, not the sun. The mechanism that best matched
the observations would involve internal heat from the planet stirring up water vapor from Saturn's
interior. That water vapor condenses in some places as air rises and releases heat as it makes clouds
and rain. This heat provides the energy to create the eddies that drive the jet streams.

The condensation of water was not actually observed; most of that process occurs at lower altitudes
not visible to Cassini. But the condensation in mid-latitude storms does happen on both Saturn and
Earth. Storms on Earth – the low- and high-pressure centers on weather maps – are driven mainly by
the sun's heating and do not mainly occur because of the condensation of water, Del Genio said. On
Saturn, the condensation heating is the main driver of the storms, and the sun's heating is not
important.

Images of one of the strongest jet streams and a figure from the paper can be found at
http://www.nasa.gov/cassini , http://saturn.jpl.nasa.gov and http://ciclops.org .

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the
Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of
Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission
Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed
and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo.

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Tuesday, June 19, 2012

Most Quasars Live on Snacks, Not Large Meals

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. PHONE 818-354-5011
http://www.jpl.nasa.gov

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

Donna Weaver / Ray Villard 410-338-4493 / 410-338-4514
Space Telescope Science Institute, Baltimore, Md.
dweaver@stsci.edu / villard@stsci.edu

News release: 2012-180 June 19, 2012

Most Quasars Live on Snacks, Not Large Meals

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-180&cid=release_2012-180

Black holes in the early universe needed a few snacks rather than one giant meal to fuel their
quasars and help them grow, according to observations from NASA's Spitzer and Hubble space
telescopes.

Quasars are the brilliant beacons of light that are powered by black holes feasting on captured
material, and in the process, heating some of the matter to millions of degrees. The brightest quasars
reside in galaxies distorted by collisions with other galaxies. These encounters send lots of gas and
dust into the gravitational whirlpool of hungry black holes.

Now, however, astronomers are uncovering an underlying population of fainter quasars that thrive
in normal-looking spiral galaxies. They are triggered by black holes snacking on such tasty treats as
a batch of gas or the occasional small satellite galaxy.

A census of 30 quasar host galaxies conducted with two of NASA's premier observatories, Hubble
and Spitzer, has found that 26 of the host galaxies bear no telltale signs of collisions with neighbors,
such as distorted shapes. Only one galaxy in the sample shows evidence of an interaction with
another galaxy. The galaxies existed roughly 8 billion to 12 billion years ago, during a peak epoch
of black-hole growth.

The study, led by Kevin Schawinski of Yale University, New Haven, Conn., bolsters evidence that
the growth of most massive black holes in the early universe was fueled by small, long-term events
rather than dramatic short-term major mergers.

"Quasars that are products of galaxy collisions are very bright," Schawinski said. "The objects we
looked at in this study are the more typical quasars. They're a lot less luminous. The brilliant
quasars born of galaxy mergers get all the attention because they are so bright and their host
galaxies are so messed up. But the typical bread-and-butter quasars are actually where most of the
black-hole growth is happening. They are the norm, and they don't need the drama of a collision to
shine."

Schawinski's science paper has been accepted for publication in a letter to the Monthly Notices of
the Royal Astronomical Society.

For his analysis, Schawinski analyzed galaxies observed by the Spitzer and Hubble telescopes in the
Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. He chose 30 dust-enshrouded
galaxies that appeared extremely bright in infrared images taken by the Spitzer telescope, a sign that
their resident black holes are feasting on surrounding material. The dust is blocking the quasar's
light at visible wavelengths. But infrared light pierces the dust, allowing Schawinski to study the
galaxies' detailed structure. The masses of those galaxies are comparable to that of our Milky Way.

Schawinski then studied the galaxies in near-infrared images taken by Hubble's Wide Field Camera
3. Hubble's sharp images allowed careful analysis of galaxy shapes, which would be significantly
distorted if major galaxy mergers had taken place and were disrupting the structure. Instead, in all
but one instance, the galaxies show no such disruption.

Whatever process is stoking the quasars, it's below the detection capability of even Hubble. "I think
it's a combination of processes, such as random stirring of gas, supernovae blasts, swallowing of
small bodies, and streams of gas and stars feeding material into the nucleus," Schawinski said.

A black hole doesn't need much gas to satisfy its hunger and turn on a quasar. "There's more than
enough gas within a few light-years from the center of our Milky Way to turn it into a quasar,"
Schawinski explained. "It just doesn't happen. But it could happen if one of those small clouds of
gas ran into the black hole. Random motions and stirrings inside the galaxy would channel gas into
the black hole. Ten billion years ago, those random motions were more common and there was
more gas to go around. Small galaxies also were more abundant and were swallowed up by larger
galaxies."

The galaxies in Schawinski's study are prime targets for NASA's upcoming James Webb Space
Telescope, a large infrared observatory scheduled to launch later this decade. "To get to the heart of
what kinds of events are powering the quasars in these galaxies, we need the Webb telescope.
Hubble and Spitzer have been the trailblazers for finding them."

The team of astronomers in this study consists of K. Schawinski, B.D. Simmons, C.M. Urry and E.
Glikman (Yale University), and E. Treister (Universidad de Concepcion, Chile).

For images and more information about this study, visit http://hubblesite.org/news/2012/27 .

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission
for NASA's Science Mission Directorate, Washington. Science operations are conducted at the
Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at
the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech.
Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu
and http://www.nasa.gov/spitzer .

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Sunday, June 17, 2012

Study Finds Ancient Warming Greened Antarctica

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.jpl.nasa.gov

Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
alan.d.buis@jpl.nasa.gov

J. D. Harrington 202-358-5241
NASA Headquarters, Washington
j.d.harrington@nasa.gov

Robert Perkins 213-740-9226
University of Southern California, Los Angeles
perkinsr@usc.edu

Zac Lemoine 225-578-1399
Louisiana State University, Baton Rouge
jlemo26@lsu.edu

News release: 2012-179 June 17, 2012

Study Finds Ancient Warming Greened Antarctica

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-179&cid=release_2012-179

PASADENA, Calif. -- A new university-led study with NASA participation finds ancient Antarctica
was much warmer and wetter than previously suspected. The climate was suitable to support
substantial vegetation -- including stunted trees -- along the edges of the frozen continent.

The team of scientists involved in the study, published online June 17 in Nature Geoscience, was led
by Sarah J. Feakins of the University of Southern California in Los Angeles, and included researchers
from NASA's Jet Propulsion Laboratory in Pasadena, Calif., and Louisiana State University in Baton
Rouge.

By examining plant leaf wax remnants in sediment core samples taken from beneath the Ross Ice
Shelf, the research team found summer temperatures along the Antarctic coast 15 to 20 million years
ago were 20 degrees Fahrenheit (11 degrees Celsius) warmer than today, with temperatures reaching
as high as 45 degrees Fahrenheit (7 degrees Celsius). Precipitation levels also were found to be
several times higher than today.

"The ultimate goal of the study was to better understand what the future of climate change may look
like," said Feakins, an assistant professor of Earth sciences at the USC Dornsife College of Letters,
Arts and Sciences. "Just as history has a lot to teach us about the future, so does past climate. This
record shows us how much warmer and wetter it can get around the Antarctic ice sheet as the climate
system heats up. This is some of the first evidence of just how much warmer it was."

Scientists began to suspect that high-latitude temperatures during the middle Miocene epoch were
warmer than previously believed when co-author Sophie Warny, assistant professor at LSU,
discovered large quantities of pollen and algae in sediment cores taken around Antarctica. Fossils of
plant life in Antarctica are difficult to come by because the movement of the massive ice sheets
covering the landmass grinds and scrapes away the evidence.

"Marine sediment cores are ideal to look for clues of past vegetation, as the fossils deposited are
protected from ice sheet advances, but these are technically very difficult to acquire in the Antarctic
and require international collaboration," said Warny.

Tipped off by the tiny pollen samples, Feakins opted to look at the remnants of leaf wax taken from
sediment cores for clues. Leaf wax acts as a record of climate change by documenting the hydrogen
isotope ratios of the water the plant took up while it was alive.

"Ice cores can only go back about one million years," Feakins said. "Sediment cores allow us to go
into 'deep time.'"

Based upon a model originally developed to analyze hydrogen isotope ratios in atmospheric water
vapor data from NASA's Aura spacecraft, co-author and JPL scientist Jung-Eun Lee created
experiments to find out just how much warmer and wetter climate may have been.

"When the planet heats up, the biggest changes are seen toward the poles," Lee said. "The southward
movement of rain bands associated with a warmer climate in the high-latitude southern hemisphere
made the margins of Antarctica less like a polar desert, and more like present-day Iceland."

The peak of this Antarctic greening occurred during the middle Miocene period, between 16.4 and
15.7 million years ago. This was well after the age of the dinosaurs, which became extinct 64 million
years ago. During the Miocene epoch, mostly modern-looking animals roamed Earth, such as three-
toed horses, deer, camel and various species of apes. Modern humans did not appear until 200,000
years ago.

Warm conditions during the middle Miocene are thought to be associated with carbon dioxide levels
of around 400 to 600 parts per million (ppm). In 2012, carbon dioxide levels have climbed to 393
ppm, the highest they've been in the past several million years. At the current rate of increase,
atmospheric carbon dioxide levels are on track to reach middle Miocene levels by the end of this
century.

High carbon dioxide levels during the middle Miocene epoch have been documented in
other studies through multiple lines of evidence, including the number of microscopic pores
on the surface of plant leaves and geochemical evidence from soils and marine organisms.
While none of these 'proxies' is as reliable as the bubbles of gas trapped in ice cores,
they are the best evidence available this far back in time. While scientists do not yet know
precisely why carbon dioxide was at these levels during the middle Miocene, high
carbon dioxide, together with the global warmth documented from many parts of
the world and now also from the Antarctic region, appear to coincide during this period in
Earth's history.

This research was funded by the U.S. National Science Foundation with additional support from
NASA. The California Institute of Technology in Pasadena manages JPL for NASA.

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

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Friday, June 15, 2012

NASA Releases Workshop Data and Findings on Asteroid 2011 AG5

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
Dwayne.c.brown@nasa.gov

News feature: 2012-178 June 15, 2012

NASA Releases Workshop Data and Findings on Asteroid 2011 AG5

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-178&cid=release_2012-178

WASHINGTON -- Researchers anticipate that asteroid 2011 AG5, discovered in January 2011, will
fly safely past and not impact Earth in 2040.

Current findings and analysis data were reported at a May 29 workshop at NASA's Goddard Space
Flight Center in Greenbelt, Md., attended by scientists and engineers from around the world.
Discussions focused on observations of potentially hazardous asteroids (PHAs).

Observations to date indicate there is a slight chance that AG5 could impact Earth in 2040. Attendees
expressed confidence that in the next four years, analysis of space and ground-based observations will
show the likelihood of 2011 AG5 missing Earth to be greater than 99 percent.

Measuring approximately 460 feet (140 meters) in size, the space rock was discovered by the NASA-
supported Catalina Sky Survey operated by the University of Arizona in Tucson. Several
observatories monitored 2011 AG5 for nine months before it moved too far away and grew too faint
to see.

"While there is general consensus there is only a very small chance that we could be dealing with a
real impact scenario for this object, we will still be watchful and ready to take further action if
additional observations indicate it is warranted," said Lindley Johnson, program executive for the
Near-Earth Object (NEO) Observation Program at NASA Headquarters in Washington.

Several years ago another asteroid, named Apophis, was thought to pose a similar impact threat in
2036. Additional observations taken from 2005 through 2008 enabled NASA scientists to refine their
understanding of the asteroid's path, which showed a significantly reduced likelihood of a hazardous
encounter.

"Any time we're able to observe an asteroid and obtain new location data, we're able to refine our
calculations of the asteroid's future path," said Don Yeomans, manager of NASA's NEO Program
Office at the Jet Propulsion Laboratory in Pasadena, Calif. "When few observations exist, our initial
orbit calculation will include a wider swath to account for uncertainties. With more data points, the
knowledge of the potential positions of the asteroid improves and the swath becomes smaller --
typically eliminating the risk of an impact."

Observations of 2011 AG5 have been limited to date because of its present location beyond the orbit
of Mars and in the daytime sky on the other side of the sun. In fall 2013, conditions will improve to
allow space- and ground-based telescopes to better track the asteroid's path. At that time, 2011 AG5
will be 91 million miles (147 million kilometers) from Earth but favorably located for observations in
the late evening sky.

The level of hazard will gain even more clarity in 2023, when the asteroid is approximately 1.1
million miles (1.8 million kilometers) from Earth. If 2011 AG5 passes through a 227-mile-wide (365-
kilometer) region in space called a keyhole in early February 2023, Earth's gravitational pull could
influence the object's orbital path just enough to bring it back for an impact on February 5, 2040. If
the asteroid misses the keyhole, an impact in 2040 will not occur.

"Given our current understanding of this asteroid's orbit, there is only a very remote chance of this
keyhole passage even occurring," said Johnson.

Although scientists widely expect it to be a safe flyby, they acknowledge the slight chance that
computed odds could rise as a result of observations to be taken from 2013 to 2016. According to the
experts at the workshop, even if the odds do increase, there is still ample time to plan and carry out at
least one of several viable missions to change the asteroid's course.

PHAs are a subset of the larger group of near-Earth asteroids. They have the closest orbits to Earth's,
coming within 5 million miles (about 8 million kilometers). They are large enough to enter Earth's
atmosphere intact and cause damage on at least a local scale. Damage from an asteroid the size of
2011 AG5 could cover a region at least a hundred miles wide.

NASA established the NEO Program in 1998 to coordinate the agency's efforts to detect, track and
characterize Earth-approaching NEOs and comets larger than 1 kilometer in size. The program now
also searches for NEOs as small as object 2011 AG5. NASA supports NEO observation, tracking and
analysis activities worldwide. Activities are coordinated through the NEO Program Office at JPL.

To read the workshop report and findings, visit: http://neo.jpl.nasa.gov/ .

For information about NASA asteroid missions and activities, visit: http://www.nasa.gov/asteroids .

EDITOR'S NOTE: Lindley Johnson and Don Yeomans are available for media interviews. To
coordinate a time and date, email Dwayne Brown at dwayne.c.brown@nasa.gov .

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Thursday, June 14, 2012

Data From NASA's Voyager 1 Point to Interstellar Future

First Flight Instrument Delivered for James Webb Space Telescope

Wednesday, June 13, 2012

Got Salt? NASA's Salt Mapper Toasts First Birthday

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Feature June 13, 2012

Got Salt? NASA's Salt Mapper Toasts First Birthday

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-173&cid=release_2012-173

Aquarius, NASA's pioneering instrument to measure ocean surface salinity from orbit, launched a year ago (on June 10, 2011) aboard the Argentine Space Agency's Satélite de Aplicaciones Científicas (SAC-D) observatory. Designed to advance our understanding of what changes in the saltiness of the ocean's top layer say about the water cycle and variations in climate, the mission has had a busy first year. Already, its measurements of global salinity patterns have observed regional features like the freshwater plume gushing from the Amazon River, localized changes in ocean saltiness following a tropical storm, and the salinity structure of large tropical ocean waves that influence global climate patterns.

A new interactive feature on NASA's Global Climate Change website, http://climate.nasa.gov , gives visitors a 'look under the hood' at the Aquarius spacecraft and a chance to meet some of the 'salt sleuths' on the Aquarius team. To take a spin, visit: http://climate.nasa.gov/Aquarius/index.cfm .

Aquarius was built by NASA's Jet Propulsion Laboratory, Pasadena, Calif.; and the Goddard Space Flight Center, Greenbelt, Md. NASA's Launch Services Program, at Kennedy Space Center in Florida, managed the launch. JPL managed Aquarius through its commissioning phase and is archiving mission data. Goddard now manages Aquarius mission operations and processes science data. Argentina's space agency, Comisión Nacional de Actividades Espaciales (CONAE), is providing the SAC-D spacecraft, optical camera, thermal camera with Canada, microwave radiometer, sensors from various Argentine institutions and the mission operations center. France and Italy also are contributing instruments.

For more on the Aquarius mission's first year in orbit, visit: http://www.nasa.gov/mission_pages/aquarius/news/first-year.html . To see recent global ocean salinity maps and movies produced from Aquarius data, visit: http://earthobservatory.nasa.gov/IOTD/view.php?id=78250 . To learn more about the new study of tropical ocean waves produced using Aquarius data, visit: http://photojournal.jpl.nasa.gov/catalog/PIA15799 . For more information about Aquarius, see: http://www.nasa.gov/aquarius , http://aquarius.nasa.gov and http://www.conae.gov.ar/eng/principal.html .

Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
alan.buis@jpl.nasa.gov

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