NASA's Spitzer Finds Distant Galaxies Grazed on Gas

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

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

Trent Perrotto 202-358-0321
Headquarters, Washington
trent.j.perrotto@nasa.gov

News release: 2011-200 June 30, 2011

NASA's Spitzer Finds Distant Galaxies Grazed on Gas

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-200&cid=release_2011-200

PASADENA, Calif. -- Galaxies once thought of as voracious tigers are more like grazing cows,
according to a new study using NASA's Spitzer Space Telescope.

Astronomers have discovered that galaxies in the distant, early universe continuously ingested their
star-making fuel over long periods of time. This goes against previous theories that the galaxies
devoured their fuel in quick bursts after run-ins with other galaxies.

"Our study shows the merging of massive galaxies was not the dominant method of galaxy growth
in the distant universe," said Ranga-Ram Chary of NASA's Spitzer Science Center at the California
Institute of Technology in Pasadena, Calif. "We're finding this type of galactic cannibalism was rare.
Instead, we are seeing evidence for a mechanism of galaxy growth in which a typical galaxy fed
itself through a steady stream of gas, making stars at a much faster rate than previously thought."

Chary is the principal investigator of the research, appearing in the Aug. 1 issue of the Astrophysical
Journal. According to his findings, these grazing galaxies fed steadily over periods of hundreds of
millions of years and created an unusual amount of plump stars, up to 100 times the mass of our sun.

"This is the first time that we have identified galaxies that supersized themselves by grazing," said
Hyunjin Shim, also of the Spitzer Science Center and lead author of the paper. "They have many
more massive stars than our Milky Way galaxy."

Galaxies like our Milky Way are giant collections of stars, gas and dust. They grow in size by
feeding off gas and converting it to new stars. A long-standing question in astronomy is: Where did
distant galaxies that formed billions of years ago acquire this stellar fuel? The most favored theory
was that galaxies grew by merging with other galaxies, feeding off gas stirred up in the collisions.

Chary and his team addressed this question by using Spitzer to survey more than 70 remote galaxies
that existed 1 to 2 billion years after the Big Bang (our universe is approximately 13.7 billion years
old). To their surprise, these galaxies were blazing with what is called H alpha, which is radiation
from hydrogen gas that has been hit with ultraviolet light from stars. High levels of H alpha indicate
stars are forming vigorously. Seventy percent of the surveyed galaxies show strong signs of H alpha.
By contrast, only 0.1 percent of galaxies in our local universe possess this signature.

Previous studies using ultraviolet-light telescopes found about six times less star formation than
Spitzer, which sees infrared light. Scientists think this may be due to large amounts of obscuring
dust, through which infrared light can sneak. Spitzer opened a new window onto the galaxies by
taking very long-exposure infrared images of a patch of sky called the GOODS fields, for Great
Observatories Origins Deep Survey.

Further analyses showed that these galaxies furiously formed stars up to 100 times faster than the
current star-formation rate of our Milky Way. What's more, the star formation took place over a long
period of time, hundreds of millions of years. This tells astronomers that the galaxies did not grow
due to mergers, or collisions, which happen on shorter timescales. While such smash-ups are
common in the universe -- for example, our Milky Way will merge with the Andromeda galaxy in
about 5 billion years -- the new study shows that large mergers were not the main cause of galaxy
growth. Instead, the results show that distant, giant galaxies bulked up by feeding off a steady supply
of gas that probably streamed in from filaments of dark matter.

Chary said, "If you could visit a planet in one of these galaxies, the sky would be a crazy place, with
tons of bright stars, and fairly frequent supernova explosions."

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope
mission for the agency's Science Mission Directorate in Washington. Science operations are
conducted at the Spitzer Science Center at Caltech. Caltech manages JPL for NASA.

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

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NASA Will Host 150 People for Tweetup at Launch of Jupiter-Bound Mission

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

Veronica McGregor 818-354-9452
Jet Propulsion Laboratory, Pasadena, Calif.
veronica.c.mcgregor@jpl.nasa.gov

Stephanie L. Schierholz 202-358-4997
Headquarters, Washington
stephanie.schierholz@nasa.gov

Advisory: 2011-194 June 24, 2011

NASA Will Host 150 People for Tweetup at Launch of Jupiter-Bound Mission

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-194&cid=release_2011-194

PASADENA, Calif. -- NASA will host a two-day launch Tweetup for 150 of its Twitter followers on
Aug. 4-5 at the agency's Kennedy Space Center in Florida. The Tweetup is expected to culminate in
the launch of the Jupiter-bound Juno spacecraft aboard an Atlas V rocket.

The launch window opens at 8:39 a.m. PDT (11:39 a.m. EDT) on Aug. 5. The spacecraft is expected
to arrive at Jupiter in 2016. The mission will investigate the gas giant's origins, structure, atmosphere
and magnetosphere. Juno's color camera will provide close-up images of Jupiter, including the first
detailed glimpse of the planet's poles.

The Tweetup will provide @NASA Twitter followers with the opportunity to tour the Kennedy Space
Center Visitor Complex; speak with scientists and engineers from the Juno and other upcoming
missions; and, if all goes as scheduled, view the spacecraft launch. The event also will provide
participants the opportunity to meet fellow tweeps and members of NASA's social media team.

Juno is the second of four space missions launching this year, making 2011 one of the busiest ever in
planetary exploration. Aquarius was launched June 10 to study ocean salinity; Grail will launch Sept.
8 to study the moon's gravity field; and the Mars Science Laboratory/Curiosity rover will head to the
Red Planet no earlier than Nov. 25.

Tweetup registration opens at noon PDT (3 p.m. EDT) on Friday, June 24, and closes at noon PDT (3
p.m. EDT) on Monday, June 27. NASA will randomly select 150 participants from online
registrations. For more information about the Tweetup and registration, visit:
http://www.nasa.gov/connect/tweetup/tweetup_jpl_08-04-2011.html .

For information about connecting and collaborating with NASA, visit: http://www.nasa.gov/connect .

Juno's principal investigator is Scott Bolton of the Southwest Research Institute in San Antonio.
NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the mission.

For more information, visit: http://www.nasa.gov/juno and http://missionjuno.swri.edu

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Dawn Nears Start of Year-Long Stay at Giant Asteroid

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

Priscilla Vega/Jia-Rui Cook 626-298-3290/818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
priscilla.r.vega@jpl.nasa.gov / jccook@jpl.nasa.gov

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

News release: 2011-192 June 23, 2011

Dawn Nears Start of Year-Long Stay at Giant Asteroid

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-192&cid=release_2011-192

PASADENA, Calif. – NASA's Dawn spacecraft is on track to begin the first extended visit to a large
asteroid. The mission expects to go into orbit around Vesta on July 16 and begin gathering science
data in early August. Vesta resides in the main asteroid belt and is thought to be the source of a large
number of meteorites that fall to Earth.

"The spacecraft is right on target," said Robert Mase, Dawn project manager at NASA's Jet
Propulsion Laboratory in Pasadena, Calif. "We look forward to exploring this unknown world during
Dawn's one-year stay in Vesta's orbit."

After traveling nearly four years and 1.7 billion miles (2.7 billion kilometers), Dawn is approximately
96,000 miles (155,000 kilometers) away from Vesta. When Vesta captures Dawn into its orbit on
July 16, there will be approximately 9,900 miles (16,000 kilometers) between them. When orbit is
achieved, they will be approximately 117 million miles (188 million kilometers) away from Earth.

After Dawn enters Vesta's orbit, engineers will need a few days to determine the exact time of
capture. Unlike other missions where a dramatic, nail-biting propulsive burn results in orbit insertion
around a planet, Dawn has been using its placid ion propulsion system to subtly shape its path for
years to match Vesta's orbit around the sun.

Images from Dawn's framing camera, taken for navigation purposes, show the slow progress toward
Vesta. They also show Vesta rotating about 65 degrees in the field of view. The images are about
twice as sharp as the best images of Vesta from NASA's Hubble Space Telescope, but the surface
details Dawn will obtain are still a mystery.

"Navigation images from Dawn's framing camera have given us intriguing hints of Vesta, but we're
looking forward to the heart of Vesta operations, when we begin officially collecting science data,"
said Christopher Russell, Dawn principal investigator, at UCLA. "We can't wait for Dawn to peel
back the layers of time and reveal the early history of our solar system."

Dawn's three instruments are all functioning and appear to be properly calibrated. The visible and
infrared mapping spectrometer, for example, has started to obtain images of Vesta that are larger than
a few pixels in size. During the initial reconnaissance orbit, at approximately 1,700 miles (2,700
kilometers), the spacecraft will get a broad overview of Vesta with color pictures and data in different
wavelengths of reflected light. The spacecraft will move into a high-altitude mapping orbit, about 420
miles (680 kilometers) above the surface to systematically map the parts of Vesta's surface
illuminated by the sun; collect stereo images to see topographic highs and lows; acquire higher-
resolution data to map rock types at the surface; and learn more about Vesta's thermal properties.

Dawn then will move even closer, to a low-altitude mapping orbit approximately 120 miles (200
kilometers) above the surface. The primary science goals of this orbit are to detect the byproducts of
cosmic rays hitting the surface and help scientists determine the many kinds of atoms there, and
probe the protoplanet's internal structure. As Dawn spirals away from Vesta, it will pause again at the
high-altitude mapping orbit. Because the sun's angle on the surface will have progressed, scientists
will be able to see previously hidden terrain while obtaining different views of surface features.

"We've packed our year at Vesta chock-full of science observations to help us unravel the mysteries
of Vesta," said Carol Raymond, Dawn's deputy principal investigator at JPL. Vesta is considered a
protoplanet, or body that never quite became a full-fledged planet.

Dawn launched in September 2007. Following a year at Vesta, the spacecraft will depart for its
second destination, the dwarf planet Ceres, in July 2012. Dawn's mission to Vesta and Ceres is
managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the
directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville,
Ala.

UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va.,
designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar
System Research, the Italian Space Agency and the Italian National Astrophysical Institute are part of
the mission team. JPL is managed for NASA by the California Institute of Technology in Pasadena.

For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .
You can also follow the mission on Twitter at: http://www.twitter.com/NASA_Dawn .

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NASA Mission Suggests Sun and Planets Constructed Differently

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

DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

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

News release: 2011-193 June 23, 2011

NASA Mission Suggests Sun and Planets Constructed Differently

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-193&cid=release_2011-193

PASADENA, Calif. – Researchers analyzing samples returned by NASA's 2004 Genesis mission
have discovered that our sun and its inner planets may have formed differently than previously
thought.

Data revealed differences between the sun and planets in oxygen and nitrogen, which are two of the
most abundant elements in our solar system. Although the difference is slight, the implications could
help determine how our solar system evolved.

"We found that Earth, the moon, as well as Martian and other meteorites which are samples of
asteroids, have a lower concentration of the O-16 than does the sun," said Kevin McKeegan, a
Genesis co-investigator from UCLA, and the lead author of one of two Science papers published this
week. "The implication is that we did not form out of the same solar nebula materials that created the
sun -- just how and why remains to be discovered."

The air on Earth contains three different kinds of oxygen atoms which are differentiated by the
number of neutrons they contain. Nearly 100 percent of oxygen atoms in the solar system are
composed of O-16, but there are also tiny amounts of more exotic oxygen isotopes called O-17 and
O-18. Researchers studying the oxygen of Genesis samples found that the percentage of O-16 in the
sun is slightly higher than on Earth or on other terrestrial planets. The other isotopes' percentages
were slightly lower.

Another paper detailed differences between the sun and planets in the element nitrogen. Like oxygen,
nitrogen has one isotope, N-14, that makes up nearly 100 percent of the atoms in the solar system, but
there is also a tiny amount of N-15. Researchers studying the same samples saw that when compared
to Earth's atmosphere, nitrogen in the sun and Jupiter has slightly more N-14, but 40 percent less N-
15. Both the sun and Jupiter appear to have the same nitrogen composition. As is the case for oxygen,
Earth and the rest of the inner solar system are very different in nitrogen.

"These findings show that all solar system objects including the terrestrial planets, meteorites and
comets are anomalous compared to the initial composition of the nebula from which the solar system
formed," said Bernard Marty, a Genesis co-investigator from Centre de Recherches Pétrographiques
et Géochimiques and the lead author of the other new Science paper. "Understanding the cause of
such a heterogeneity will impact our view on the formation of the solar system."

Data were obtained from analysis of samples Genesis collected from the solar wind, or material
ejected from the outer portion of the sun. This material can be thought of as a fossil of our nebula
because the preponderance of scientific evidence suggests that the outer layer of our sun has not
changed measurably for billions of years.

"The sun houses more than 99 percent of the material currently in our solar system, so it's a good idea
to get to know it better," said Genesis Principal Investigator Don Burnett of the California Institute of
Technology, Pasadena, Calif. "While it was more challenging than expected, we have answered some
important questions, and like all successful missions, generated plenty more."

Genesis launched in August 2000. The spacecraft traveled to Earth's L1 Lagrange Point about 1
million miles from Earth, where it remained for 886 days between 2001 and 2004, passively
collecting solar-wind samples.

On Sept. 8, 2004, the spacecraft released a sample return capsule, which entered Earth's atmosphere.
Although the capsule made a hard landing as a result of a failed parachute in the Utah Test and
Training Range in Dugway, Utah, it marked NASA's first sample return since the final Apollo lunar
mission in 1972, and the first material collected beyond the moon. NASA's Johnson Space Center in
Houston curates the samples and supports analysis and sample allocation.

The Jet Propulsion Laboratory, Pasadena, Calif., managed the Genesis mission for NASA's Science
Mission Directorate, Washington. The Genesis mission was part of the Discovery Program managed
at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems,
Denver, developed and operated the spacecraft. Analysis at the Centre de Recherches
Pétrographiques et Géochimiques, Nancy, France, was supported by the Centre National d'Etudes
Spatiales, Paris, and the Centre National de la Recherche Scientifique, Paris, France.

For more information on the Genesis mission, visit: genesismission.jpl.nasa.gov .

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NASA Mars Rover Arrives in Florida After Cross-Country Flight

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

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

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

George Diller 321-867-2468
Kennedy Space Center, Fla.
george.h.diller@nasa.gov

News release: 2011-191 June 23, 2011

NASA Mars Rover Arrives in Florida After Cross-Country Flight

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-191&cid=release_2011-191

PASADENA, Calif. -- NASA's next Mars rover has completed the journey from its California
birthplace to Florida in preparation for launch this fall.

The Mars Science Laboratory rover, also known as Curiosity, arrived late Wednesday night at
NASA's Kennedy Space Center aboard an Air Force C-17 transport plane. It was accompanied by the
rocket-powered descent stage that will fly the rover during the final moments before landing on Mars.
The C-17 flight began at March Air Reserve Base in Riverside, Calif., where the boxed hardware had
been trucked from NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The rover's aeroshell -- the protective covering for the trip to the Red Planet -- and the cruise stage,
which will guide it to Mars, arrived at Kennedy last month. The mission is targeted to launch from
Cape Canaveral Air Force Station between Nov. 25 and Dec. 18. The car-size rover will land on Mars
in August 2012.

"The design and building part of the mission is nearly behind us now," said JPL's David Gruel, who
has managed Mars Science Laboratory assembly, test and launch operations since 2007. "We're
getting to final checkouts before sending the rover on its way to Mars."

The rover and other spacecraft components will undergo more testing before mission staff stack them
and fuel the onboard propulsion systems. Curiosity should be enclosed in its aeroshell for the final
time in September and delivered to Kennedy's Launch Complex 41 in early November for integration
with a United Launch Alliance Atlas V rocket.

Curiosity is about twice as long and more than five times as heavy as any previous Mars rover. Its 10
science instruments include two for ingesting and analyzing samples of powdered rock delivered by
the rover's robotic arm. During a prime mission lasting one Martian year -- nearly two Earth years --
researchers will use the rover's tools to study whether the landing region has had environmental
conditions favorable for supporting microbial life and favorable for preserving clues about whether
life existed.

JPL built the rover and descent stage and manages the mission for NASA's Science Mission
Directorate in Washington. Launch management for the mission is the responsibility of NASA's
Launch Services Program at Kennedy. The California Institute of Technology in Pasadena manages
JPL for NASA.

For more information about the mission, visit: www.nasa.gov/msl .

To follow the mission on Facebook and Twitter, visit: http://www.facebook.com/marscuriosity or
http://www.twitter.com/marscuriosity .

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Cassini Captures Ocean-Like Spray at Saturn Moon

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

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

Markus Bauer 011-31-71-565-6799
European Space Agency, Noordwijk, the Netherlands
markus.bauer@esa.int

News release: 2011-190 June 22, 2011

Cassini Captures Ocean-Like Spray at Saturn Moon

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-190&cid=release_2011-190

PASADENA, Calif. – NASA's Cassini spacecraft has discovered the best evidence yet for a large-
scale saltwater reservoir beneath the icy crust of Saturn's moon Enceladus. The data came from the
spacecraft's direct analysis of salt-rich ice grains close to the jets ejected from the moon.

Data from Cassini's cosmic dust analyzer show the grains expelled from fissures, known as tiger
stripes, are relatively small and predominantly low in salt far away from the moon. But closer to the
moon's surface, Cassini found that relatively large grains rich with sodium and potassium dominate
the plumes. The salt-rich particles have an "ocean-like" composition and indicate that most, if not all,
of the expelled ice and water vapor comes from the evaporation of liquid salt water. The findings
appear in this week's issue of the journal Nature.

"There currently is no plausible way to produce a steady outflow of salt-rich grains from solid ice
across all the tiger stripes other than salt water under Enceladus's icy surface," said Frank Postberg, a
Cassini team scientist at the University of Heidelberg, Germany, and the lead author on the paper.
When water freezes, the salt is squeezed out, leaving pure water ice behind. If the plumes emanated
from ice, they should have very little salt in them.

The Cassini mission discovered Enceladus' water-vapor and ice jets in 2005. In 2009, scientists
working with the cosmic dust analyzer examined some sodium salts found in ice grains of Saturn's E
ring, the outermost ring that gets its material primarily from Enceladean jets. But the link to
subsurface salt water was not definitive.

The new paper analyzes three Enceladus flybys in 2008 and 2009 with the same instrument, focusing
on the composition of freshly ejected plume grains. The icy particles hit the detector target at speeds
between 15,000 and 39,000 mph (23,000 and 63,000 kilometers per hour), vaporizing instantly.
Electrical fields inside the cosmic dust analyzer separated the various constituents of the impact
cloud.

The data suggest a layer of water between the moon's rocky core and its icy mantle, possibly as deep
as about 50 miles (80 kilometers) beneath the surface. As this water washes against the rocks, it
dissolves salt compounds and rises through fractures in the overlying ice to form reserves nearer the
surface. If the outermost layer cracks open, the decrease in pressure from these reserves to space
causes a plume to shoot out. Roughly 400 pounds (200 kilograms) of water vapor is lost every second
in the plumes, with smaller amounts being lost as ice grains. The team calculates the water reserves
must have large evaporating surfaces, or they would freeze easily and stop the plumes.

"This finding is a crucial new piece of evidence showing that environmental conditions favorable to
the emergence of life can be sustained on icy bodies orbiting gas giant planets," said Nicolas
Altobelli, the European Space Agency's project scientist for Cassini.

Cassini's ultraviolet imaging spectrograph also recently obtained complementary results that support
the presence of a subsurface ocean. A team of Cassini researchers led by Candice Hansen of the
Planetary Science Institute in Tucson, Ariz., measured gas shooting out of distinct jets originating in
the moon's south polar region at five to eight times the speed of sound, several times faster than
previously measured. These observations of distinct jets, from a 2010 flyby, are consistent with
results showing a difference in composition of ice grains close to the moon's surface and those that
made it out to the E ring. That paper was published in the June 9 issue of Geophysical Research
Letters.

"Without an orbiter like Cassini to fly close to Saturn and its moons -- to taste salt and feel the
bombardment of ice grains -- scientists would never have known how interesting these outer solar
system worlds are," said Linda Spilker, NASA's Cassini project scientist at the Jet Propulsion
Laboratory in Pasadena, Calif.

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

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

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Radar for Mars Gets Flight Tests at NASA Dryden

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

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Feature: 2011-188 June 21, 2011

Radar for Mars Gets Flight Tests at NASA Dryden

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-188&cid=release_2011-188

Southern California's high desert has been a stand-in for Mars for NASA technology testing
many times over the years. And so it is again, in a series of flights by an F/A-18 aircraft to test
the landing radar for NASA's Mars Science Laboratory mission.

The flight profile is designed to have the F/A-18 climb to 40,000 feet (about 12,000 meters).
From there, it makes a series of subsonic, stair-step dives at angles of 40 to 90 degrees to
simulate what the Mars radar will see while the spacecraft is on a parachute descending
through the Martian atmosphere. The F/A-18 pulls out of each dive at 5,000 feet (about 1,500
meters. Data collected by these flights will be used to finesse the Mars landing radar software,
to help ensure that it is calibrated as accurately as possible.

The testing is a collaboration of NASA's Dryden Flight Research Center, Edwards, Calif., with
NASA's Jet Propulsion Laboratory, Pasadena, Calif. Earlier tests, with a helicopter carrying the
test radar, simulated the lower-altitude portion of the spacecraft's descent to the surface of
Mars. For more information about the F/A-18 tests, see
http://www.nasa.gov/topics/solarsystem/features/F-18_flying_msl_radar.html .

The Mars Science Laboratory mission's rover, named Curiosity, will be shipped this month from
JPL to NASA's Kennedy Space Center in Florida to be readied for launch between Nov. 25 and
Dec. 18, 2011. The spacecraft will arrive at Mars in August 2012. After Curiosity lands on Mars,
researchers will use the rover's 10 science instruments during the following two years to
investigate whether the landing area has ever offered environmental conditions favorable for
microbial life.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars
Science Laboratory Project for the NASA Science Mission Directorate, Washington. More
information about the mission is online at: http://marsprogram.jpl.nasa.gov/msl/ .

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NASA Hosts Preview of Visit to Large Asteroid

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 Cook/Priscilla Vega 818-354-0474/354-1357
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov / priscilla.r.vega@jpl.nasa.gov

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

Event advisory: 2011-187b June 20, 2011

NASA Hosts Preview of Visit to Large Asteroid

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-187&cid=release_2011-187

PASADENA, Calif. -- NASA will host a news briefing at 11 a.m. PDT (2 p.m. EDT) on Thursday,
June 23, to discuss the Dawn spacecraft's year-long visit to the large asteroid Vesta. The mission is
expected to go into orbit around Vesta on July 16 and begin gathering science data in early August.

The event will be held at NASA Headquarters in Washington and will be broadcast live on NASA
Television and streamed at http://www.nasa.gov/ntv . In addition, the event will be carried live on
Ustream, with a live chat available, at http://www.ustream.tv/nasajpl2 .

Local reporters are invited to watch via satellite, with two-way question-and-answer capability, at
NASA's Jet Propulsion Laboratory in Pasadena, Calif. Reporters who would like to come to JPL
must RSVP to the Media Relations Office in advance at 818-354-5011. Valid media credentials
are required, and non-U.S. citizens must also bring a passport.

Dawn's visit to Vesta will be the first prolonged encounter with a main belt asteroid and the first trip
to a protoplanet, a large body that almost became a planet. Observations will help us understand the
earliest chapter of our solar system's history.

The panelists are:
-- W. James Adams, deputy director, Planetary Science Directorate, NASA Headquarters
-- Robert Mase, Dawn project manager, NASA's Jet Propulsion Laboratory, Pasadena, Calif.
-- Christopher Russell, Dawn principal investigator, UCLA
-- Carol Raymond, Dawn deputy principal investigator, JPL

Reporters may attend the event, ask questions from participating NASA locations or join by phone.
To obtain dial-in information, journalists must e-mail Dwayne Brown at dwayne.c.brown@nasa.gov
with their name, media affiliation and work telephone number by 11 a.m. on June 23.

For more information about Dawn, visit: http://www.nasa.gov/dawn . JPL is managed for NASA by
the California Institute of Technology in Pasadena.

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Science Paper Details NASA Epoxi Flyby of Hyper Comet

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

DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif
agle@jpl.nasa.gov

Feature: 2011-185 June 16, 2011

Science Paper Details NASA Epoxi Flyby of Hyper Comet

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-185&cid=release_2011-185

PASADENA, Calif. – Comet Hartley 2's hyperactive state, as studied by NASA's EPOXI mission, is
detailed in a new paper published in this week's issue of the journal Science.

After visiting a comet and imaging distant stars for hints of extrasolar planets, you could say the
spacecraft used for EPOXI had seen its fair share of celestial wonders. But after about 3.2 billion
miles (5.1 billion kilometers) of deep space travel, one final wonder awaited the mission's
project and science teams. On Nov. 4, 2010, the EPOXI mission spacecraft flew past a weird
little comet called Hartley 2.

"From all the imaging we took during approach, we knew the comet was a little skittish even
before flyby," said EPOXI Project Manager Tim Larson of NASA's Jet Propulsion Laboratory in
Pasadena, Calif. "It was moving around the sky like a knuckleball and gave my navigators fits,
and these new results show this little comet is downright hyperactive."

The EPOXI mission found that the strong activity in water release and carbon dioxide-powered
jets did not occur equally in the different regions of the comet. During the spacecraft's flyby of
the comet – with closest approach of 431 miles (694 kilometers) – carbon-dioxide-driven jets
were seen at the ends of the comet, with most occurring at the small end. In the middle region,
or waist of the comet, water was released as vapor with very little carbon dioxide or ice. The
latter findings indicate that material in the waist likely came off the ends of the comet and was
redeposited.

"Hartley 2 is a hyperactive little comet, spewing out more water than most other comets its
size," said Mike A'Hearn, principal investigator of EPOXI from the University of Maryland,
College Park. "When warmed by the sun, dry ice -- frozen carbon dioxide -- deep in the comet's
body turns to gas jetting off the comet and dragging water ice with it."

Although Hartley 2 is the only such hyperactive comet visited by a spacecraft, scientists know of
at least a dozen other comets that also are relatively high in activity for their size and which are
probably driven by carbon dioxide or carbon monoxide.

"These could represent a separate class of hyperactive comets," said A'Hearn. "Or they could be
a continuum in comet activity extending from Hartley 2-like comets all the way to the much less
active, 'normal' comets that we are more used to seeing."

The study provides several new twists in the unfolding story of this small cometary dynamo,
including: (1) Hartley 2 has an 'excited state of rotation' because it spins around one axis, but
also tumbles around a different axis; and (2) on its larger, rougher ends, the comet's surface is
dotted with glittering blocks that can reach approximately 165 feet (50 meters) high and 260
feet (80 meters) wide. The block-like, shiny objects, some as big as one block long and 16
stories tall, appear to be two to three times more reflective than the surface average.

EPOXI was an extended mission that utilized the already "in-flight" Deep Impact spacecraft to
explore distinct celestial targets of opportunity. The name EPOXI itself is a combination of the
names for the two extended mission components: the extrasolar planet observations, called
Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2,
called the Deep Impact Extended Investigation (DIXI). The spacecraft retained the name "Deep
Impact." During its approach, encounter and departure from comet Hartley 2, the spacecraft
beamed back more than 117,000 images and spectra.

JPL managed the EPOXI and Deep Impact missions for NASA's Science Mission Directorate,
Washington. The EPOXI mission was part of the Discovery Program managed at NASA's
Marshall Space Flight Center in Huntsville, Ala. The University of Maryland, College Park, is
home to Michael A'Hearn, principal investigator for EPOXI. Drake Deming of NASA's Goddard
Space Flight Center, Greenbelt, Md., is the science lead for the EPOXI mission's extrasolar
planet observations. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp.,
Boulder, Colo.

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Educator Workshop: Mass versus Weight

Professional Development June 16, 2011

This is a feature from the NASA/JPL Education Office

Educator Workshop: Mass versus Weight

Date: Saturday, June 25, 2011, 10 a.m. - 12 p.m.

Target audience: Teachers, grades 5 - 8

Location: JPL's Educator Resource Center, Pomona, CA

Overview: Students often confuse the terms "mass" and "weight" and use them interchangeably even though they have very different meanings. Each activity in the Mass vs. Weight series demonstrates the difference between mass and weight by comparing results with video clips filmed by astronauts performing similar activities onboard the International Space Station. Students perform the activities in the classroom, record, analyze and interpret their data.

Please call the Educator Resource Center (http://www.jpl.nasa.gov/education/index.cfm?page=115 ) to register.

More Information: http://www.jpl.nasa.gov/education/index.cfm?page=110


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Recalculating the Distance to Interstellar Space

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

Feature: 2011-182 June 15, 2011

Recalculating the Distance to Interstellar Space

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-182&cid=release_2011-182

Scientists analyzing recent data from NASA's Voyager and Cassini spacecraft have
calculated that Voyager 1 could cross over into the frontier of interstellar space at any time
and much earlier than previously thought. The findings are detailed in this week's issue of
the journal Nature.

Data from Voyager's low-energy charged particle instrument, first reported in December
2010, have indicated that the outward speed of the charged particles streaming from the
sun has slowed to zero. The stagnation of this solar wind has continued through at least
February 2011, marking a thick, previously unpredicted "transition zone" at the edge of our
solar system.

"There is one time we are going to cross that frontier, and this is the first sign it is upon us,"
said Tom Krimigis, prinicipal investigator for Voyager's low-energy charged particle
instrument and Cassini's magnetospheric imaging instrument, based at the Johns Hopkins
University Applied Physics Laboratory in Laurel, Md.

Krimigis and colleagues combined the new Voyager data with previously unpublished
measurements from the ion and neutral camera on Cassini's magnetospheric imaging
instrument. The Cassini instrument collects data on neutral atoms streaming into our solar
system from the outside.

The analysis indicates that the boundary between interstellar space and the bubble of
charged particles the sun blows around itself is likely between 10 and 14 billion miles (16 to
23 kilometers) from the sun, with a best estimate of approximately 11 billion miles (18 billion
kilometers). Since Voyager 1 is already nearly 11 billion miles (18 billion kilometers) out, it
could cross into interstellar space at any time.

"These calculations show we're getting close, but how close? That's what we don't know,
but Voyager 1 speeds outward a billion miles every three years, so we may not have long to
wait," said Ed Stone, Voyager project scientist, based at the California Institute of
Technology in Pasadena.

Scientists intend to keep analyzing the Voyager 1 data, looking for confirmation. They will
also be studying the Voyager 2 data, but Voyager 2 is not as close to the edge of the solar
system as Voyager 1. Voyager 2 is about 9 billion miles (14 billion kilometers) away from the
sun.

Launched in 1977, the Voyager twin spacecraft have been on a 33-year journey. They are
humanity's farthest working deep space sentinels enroute to reach the edge of interstellar
space. The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif.,
which continues to operate both spacecraft. The Voyager missions are a part of the NASA
Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA's
Science Mission Directorate in Washington. JPL is managed for NASA by Caltech.

More information about Voyager is available at: http://www.nasa.gov/voyager and
http://voyager.jpl.nasa.gov .

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New Insights on How Solar Minimums Affect Earth

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

Written by Karen C. Fox
NASA's Goddard Space Flight Center, Greenbelt, Md.

Media contact:
DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif
agle@jpl.nasa.gov

Feature: 2011-181 June 14, 2011

New Insights on How Solar Minimums Affect Earth

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-181&cid=release_2011-181

Since 1611, humans have recorded the comings and goings of black spots on
the sun. The number of these sunspots waxes and wanes over approximately an
11-year cycle -- more sunspots generally mean more activity and eruptions on
the sun and vice versa. The number of sunspots can change from cycle to cycle,
and 2008 saw the longest and weakest solar minimum since scientists have
been monitoring the sun with space-based instruments.

Observations have shown, however, that magnetic effects on Earth due to the
sun, effects that cause the aurora to appear, did not go down in synch with the
cycle of low magnetism on the sun. Now, a paper in Annales Geophysicae that
appeared on May 16, 2011 reports that these effects on Earth did in fact reach a
minimum -- indeed they attained their lowest levels of the century -- but some
eight months later. The scientists believe that factors in the speed of the solar
wind, and the strength and direction of the magnetic fields embedded within it,
helped produce this anomalous low.

"Historically, the solar minimum is defined by sunspot number," says space
weather scientist Bruce Tsurutani at NASA's Jet Propulsion Laboratory in
Pasadena, Calif., who is first author on the paper. "Based on that, 2008 was
identified as the period of solar minimum. But the geomagnetic effects on Earth
reached their minimum quite some time later, in 2009. So we decided to look at
what caused the geomagnetic minimum."

Geomagnetic effects basically amount to any magnetic changes on Earth due to
the sun, and they're measured by magnetometer readings on the surface of the
Earth. Such effects are usually harmless, with the only obvious sign of their
presence being the appearance of auroras near the poles. However, in extreme
cases, they can cause power grid failures on Earth or induce dangerous currents
in long pipelines, so it is valuable to know how the geomagnetic effects vary with
the sun.

Three things help determine how much energy from the sun is transferred to
Earth's magnetosphere from the solar wind: the speed of the solar wind, the
strength of the magnetic field outside Earth's bounds (known as the
interplanetary magnetic field) and which direction it is pointing, since a large
southward component is necessary to connect successfully to Earth's
magnetosphere and transfer energy. The team -- which also included Walter
Gonzalez and Ezequiel Echer of the Brazilian National Institute for Space
Research in São José dos Campos, Brazil -- examined each component in turn.

First, the researchers noted that in 2008 and 2009, the interplanetary magnetic
field was the lowest it had been in the history of the space age. This was an
obvious contribution to the geomagnetic minimum. But since the geomagnetic
effects didn't drop in 2008, it could not be the only factor.

To examine the speed of the solar wind, they turned to NASA's Advanced
Composition Explorer (ACE), which is in interplanetary space outside the Earth's
magnetosphere, approximately 1 million miles toward the sun. The ACE data
showed that the speed of the solar wind stayed high during the sunspot
minimum. Only later did it begin a steady decline, correlating to the timing of the
decline in geomagnetic effects.

The next step was to understand what caused this decrease. The team found a
culprit in something called coronal holes. Coronal holes are darker, colder areas
within the sun's outer atmosphere. Fast solar wind shoots out the center of
coronal holes at speeds up to 500 miles per second, but wind flowing out of the
sides slows down as it expands into space.

"Usually, at solar minimum, the coronal holes are at the sun's poles," says
Giuliana de Toma, a solar scientist at the National Center for Atmospheric
Research whose research on this topic helped provide insight for this paper.
"Therefore, Earth receives wind from only the edges of these holes, and it's not
very fast. But in 2007 and 2008, the coronal holes were not confined to the poles
as normal."

Those coronal holes lingered at low latitudes to the end of 2008. Consequently,
the center of the holes stayed firmly pointed towards Earth, sending fast solar
wind in Earth's direction. Only as they finally appeared closer to the poles in
2009 did the speed of the solar wind at Earth begin to slow down. And, of course,
the geomagnetic effects and sightings of the aurora along with it.

Coronal holes seem to be responsible for minimizing the southward direction of
the interplanetary magnetic field as well. The solar wind's magnetic fields
oscillate on the journey from the sun to Earth. These fluctuations are known as
Alfvén waves. The wind coming out of the centers of the coronal holes has large
fluctuations, meaning that the southward magnetic component – like that in all
the directions -- is fairly large. The wind that comes from the edges, however,
has smaller fluctuations, and comparably smaller southward components. So,
once again, coronal holes at lower latitudes would have a better chance of
connecting with Earth's magnetosphere and causing geomagnetic effects, while
mid-latitude holes would be less effective.

Working together, these three factors -- low interplanetary magnetic field
strength, combined with slower solar wind speed and smaller magnetic
fluctuations due to coronal hole placement -- create the perfect environment for a
geomagnetic minimum.

Knowing what situations cause and suppress intense geomagnetic activity on
Earth is a step toward better predicting when such events might happen. To do
so well, Tsurutani points out, requires focusing on the tight connection between
such effects and the complex physics of the sun. "It's important to understand all
of these features better," he says. "To understand what causes low interplanetary
magnetic fields and what causes coronal holes in general. This is all part of the
solar cycle. And all part of what causes effects on Earth."

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NASA Spacecraft Captures Video of Asteroid Approach

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 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: 2011-179 June 13, 2011

NASA Spacecraft Captures Video of Asteroid Approach

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-179&cid=release_2011-179

PASADENA, Calif. – Scientists working with NASA's Dawn spacecraft have created a new video
showing the giant asteroid Vesta as the spacecraft approaches this unexplored world in the main
asteroid belt.

The video loops 20 images obtained for navigation purposes on June 1. The images show a dark
feature near Vesta's equator moving from left to right across the field of view as Vesta rotates.
Images also show Vesta's jagged, irregular shape, hinting at the enormous crater known to exist at
Vesta's south pole.

To see the video, visit: http://www.nasa.gov/dawn .

The images were obtained by a framing camera during a 30-minute period and show about 30 degrees
of a rotation. The pixel size in these images is approaching the resolution of the best Hubble Space
Telescope images of Vesta.

"Like strangers in a strange land, we're looking for familiar landmarks," said Jian-Yang Li, a Dawn
participating scientist from the University of Maryland, College Park. "The shadowy spot is one of
those -- it appears to match a feature, known as 'Feature B,' from images of Vesta taken by NASA's
Hubble Space Telescope."

Before orbiting Vesta on July 16, Dawn will gently slow down to about 75 mph (120 kilometers per
hour). NASA is expecting to release more images on a weekly basis, with more frequent images
available once the spacecraft begins collecting science at Vesta.

"Vesta is coming more and more into focus," said Andreas Nathues, framing camera lead
investigator, based at the Max Planck Institute for Solar System Research, Katlenburg-Lindau,
Germany. "Dawn's framing camera is working exactly as anticipated."

The Dawn mission is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., for the
agency's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery
Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible
for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the Dawn
spacecraft. The framing cameras were developed and built under the leadership of the Max Planck
Institute for Solar System Research in Katlenburg-Lindau, Germay. The German Aerospace Center
(DLR) Institute of Planetary Research in Berlin made significant contributions in coordination with
the Institute of Computer and Communication Network Engineering in Braunschweig. The framing
camera project is funded by the Max Planck Society, DLR and NASA. JPL is a division of the
California Institute of Technology in Pasadena.

For more information about Dawn, visit: http://www.nasa.gov/dawn . You can follow the mission on
Twitter at: http://twitter.com/NASA_Dawn .

More information about JPL is online at: http://www.jpl.nasa.gov .

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NASA's 'Age of Aquarius' Dawns With California Launch

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

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

News release: 2011-178 June 10, 2011

NASA's 'Age of Aquarius' Dawns With California Launch

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-178&cid=release_2011-178

PASADENA, Calif. – NASA's 'Age of Aquarius' dawned Friday with the launch of an international
satellite carrying the agency-built Aquarius instrument that will measure the saltiness of Earth's
oceans to advance our understanding of the global water cycle and improve climate forecasts.

The Aquarius/SAC-D observatory rocketed into space from Vandenberg Air Force Base in California
atop a United Launch Alliance Delta II rocket at 7:20:13 a.m. PDT (10:20:13 a.m. EDT). Less than
57 minutes later, the observatory separated from the rocket's second stage and began activation
procedures, establishing communications with ground controllers and unfurling its solar arrays.

Initial telemetry reports show the observatory is in excellent health. The SAC-D (Satélite de
Aplicaciones Científicas) observatory is a collaboration between NASA and Argentina's space
agency, Comisión Nacional de Actividades Espaciales (CONAE).

"Aquarius is a critical component of our Earth sciences work, and part of the next generation of
space-based instruments that will take our knowledge of our home planet to new heights," said
NASA Deputy Administrator Lori Garver. "The innovative scientists and engineers who contributed
to this mission are part of the talented team that will help America win the future and make a positive
impact across the globe."

Aquarius will make NASA's first space observations of the salinity, or concentration of salt, at the
ocean surface, a key missing variable in satellite studies of Earth. Variations in salinity influence
deep ocean circulation, trace the path of freshwater around our planet and help drive Earth's climate.

"Data from this mission will advance our understanding of the ocean and prediction of the global
water cycle," said Michael Freilich, director of NASA's Earth Science Division in the Science
Mission Directorate at agency headquarters in Washington. "This mission demonstrates the power of
international collaboration and accurate spaceborne measurements for science and societal benefit.
This would not be possible without the sustained cooperation of NASA, CONAE and our other
partners."

In addition to Aquarius, the observatory carries seven instruments that will monitor natural hazards
and collect a broad range of environmental data. Other mission partners include Brazil, Canada,
France and Italy.

"This mission is the most outstanding project in the history of scientific and technological
cooperation between Argentina and the United States," said CONAE Executive and Technical
Director Conrado Varotto. "Information from the mission will have significant benefits for
humankind."

Aquarius will map the global open ocean once every seven days for at least three years with a
resolution of 93 miles (150 kilometers). The maps will show how ocean surface salinity changes each
month, season and year. Scientists expect to release preliminary salinity maps later this year.

Aquarius will measure salinity by sensing thermal microwave emissions from the water's surface
with three microwave instruments called radiometers. When other environmental factors are equal,
these emissions indicate the saltiness of surface water. A microwave radar scatterometer instrument
will measure ocean waves that affect the precision of the salinity measurement. Because salinity
levels in the open ocean vary by only about five parts per thousand, Aquarius will be able to detect
changes as small as approximately two parts per 10,000, equivalent to about one-eighth of a teaspoon
of salt in a gallon of water.

During the next 25 days, the Aquarius/SAC-D service platform will be tested and maneuvered into its
final operational, near-polar orbit 408 miles (657 kilometers) above Earth. Science operations will
begin after the observatory's instruments are checked out. This commissioning phase may last up to
65 days.

Aquarius was built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the Goddard Space
Flight Center in Greenbelt, Md. NASA's Launch Services Program, at Kennedy Space Center in
Florida, managed the launch. JPL will manage Aquarius through its commissioning phase and
archive mission data. Goddard will manage Aquarius mission operations and process science data.
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 information about Aquarius/SAC-D, visit:
http://www.nasa.gov/aquarius and http://www.conae.gov.ar.eng/principal.html .

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

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Probes Suggest Magnetic Bubbles at Solar System Edge

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

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

News release: 2011-176 June 9, 2011

Probes Suggest Magnetic Bubbles at Solar System Edge

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-176&cid=release_2011-176

PASADENA, Calif. -- Observations from NASA's Voyager spacecraft, humanity's farthest deep space
sentinels, suggest the edge of our solar system may not be smooth, but filled with a turbulent sea of
magnetic bubbles.

While using a new computer model to analyze Voyager data, scientists found the sun's distant
magnetic field is made up of bubbles approximately 100 million miles (160 million kilometers) wide.
The bubbles are created when magnetic field lines reorganize. The new model suggests the field lines
are broken up into self-contained structures disconnected from the solar magnetic field. The findings
are described in the June 9 edition of the Astrophysical Journal.

Like Earth, our sun has a magnetic field with a north pole and a south pole. The field lines are
stretched outward by the solar wind, a stream of charged particles emanating from the star that
interacts with material expelled from others in our corner of the Milky Way galaxy. The Voyager
spacecraft, more than 9 billion miles (14 billion kilometers) away from Earth, are traveling in a
boundary region. In that area, the solar wind and magnetic field are affected by material expelled from
other stars in our corner of the Milky Way galaxy.

"The sun's magnetic field extends all the way to the edge of the solar system," said astronomer Merav
Opher of Boston University. "Because the sun spins, its magnetic field becomes twisted and wrinkled,
a bit like a ballerina's skirt. Far, far away from the sun, where the Voyagers are, the folds of the skirt
bunch up."

Understanding the structure of the sun's magnetic field will allow scientists to explain how galactic
cosmic rays enter our solar system and help define how the star interacts with the rest of the galaxy.

So far, much of the evidence for the existence of the bubbles originates from an instrument aboard the
spacecraft that measures energetic particles. Investigators are studying more information and hoping to
find signatures of the bubbles in the Voyager magnetic field data.

"We are still trying to wrap our minds around the implications of the findings," said University of
Maryland physicist Jim Drake, one of Opher's colleagues.

Launched in 1977, the Voyager twin spacecraft have been on a 33-year journey. They are en route to
reach the edge of interstellar space. NASA's Jet Propulsion Laboratory in Pasadena, Calif., built the
spacecraft and continues to operate them. The Voyager missions are a part of the Heliophysics System
Observatory, sponsored by the Heliophysics Division of NASA's Science Mission Directorate in
Washington. JPL is a division of the California Institute of Technology in Pasadena.

To view supporting images about the research, visit: http://www.nasa.gov/sunearth .

More information about Voyager is available at: http://www.nasa.gov/voyager and
http://voyager.jpl.nasa.gov .

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NASA's Aquarius/SAC-D Launch Rescheduled

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

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

George Diller 805-605-3051
Kennedy Space Center, Fla.
george.h.diller@nasa.gov

Feature: 2011-175 June 8, 2011

NASA's Aquarius/SAC-D Launch Rescheduled

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-175&cid=release_2011-175

PASADENA, Calif. -- The launch of the international Aquarius/SAC-D mission is
postponed 24 hours until Friday, June 10, from NASA's Space Launch Complex-2 at
Vandenberg Air Force Base, Calif. The 5-minute launch window opens at 7:20 a.m. PDT
(10:20 a.m. EDT).

The new launch date will allow the launch team to complete additional review of an
inconsistency found in the Delta II launch vehicle flight profile for wind conditions on
the day of launch. These data are used to steer the Delta II through upper level winds.
The weather forecast for June 10 shows a 100 percent chance of favorable weather
conditions for the launch.

The Aquarius/SAC-D (Satelite de Aplicaciones Cientificas) observatory is a collaboration
between NASA and Argentina's space agency, Comision Nacional de Actividades
Espaciales (CONAE).

Media are invited to see and photograph the Delta II with Aquarius/SAC-D at the launch
pad on Thursday, June 9. Media will depart for the pad at 9:30 p.m. PDT from the
Vandenberg Main Gate on California State Road 1.

Media covering the launch on Friday, June 10, will be escorted to the press viewing site
from the Vandenberg Main Gate. Media should meet at 6 a.m. PDT at the pass and
identification building.

Aquarius was built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the
Goddard Space Flight Center in Greenbelt, Md. NASA's Launch Services Program at the
Kennedy Space Center in Florida manages the launch. JPL will manage Aquarius through
its commissioning phase and archive mission data. Goddard will manage Aquarius
mission operations and process science data. 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.

On launch day, June 10, NASA TV commentary coverage of the countdown will begin at
5:30 a.m. PDT (8:30 a.m. EDT). Launch coverage will be streamed live at:
http://www.nasa.gov/ntv .

For more information about Aquarius/SAC-D, visit: http://www.nasa.gov/aquarius . JPL
is managed for NASA by the California Institute of Technology in Pasadena.

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New NASA Salt Mapper to Spice Up Climate Forecasts

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

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

Feature: 2011-169 June 2, 2011

New NASA Salt Mapper to Spice Up Climate Forecasts

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-169&cid=release_2011-169

Salt is essential to human life. Most people don't know, however, that salt -- in a form
nearly the same as the simple table variety -- is just as essential to Earth's ocean,
serving as a critical driver of key ocean processes. While ancient Greek soothsayers
believed they could foretell the future by reading the patterns in sprinkled salt, today's
scientists have learned that they can indeed harness this invaluable mineral to foresee
the future -- of Earth's climate.

The oracles of modern climate science are the computer models used to forecast
climate change. These models, which rely on a myriad of data from many sources, are
effective in predicting many climate variables, such as global temperatures. Yet data for
some pieces of the climate puzzle have been scarce, including the concentration of
dissolved sea salt at the surface of the world's ocean, commonly called ocean surface
salinity, subjecting the models to varying margins of error. This salinity is a key indicator
of how Earth's freshwater moves between the ocean, land and atmosphere.

Enter Aquarius, a new NASA salinity-measurement instrument slated for launch in June
2011 aboard the Satélite de Aplicaciones Científicas (SAC)-D spacecraft built by
Argentina's Comisión Nacional de Actividades Espaciales (CONAE). Aquarius' high-
tech, salt-seeking sensors will make comprehensive measurements of ocean surface
salinity with the precision needed to help researchers better determine how Earth's
ocean interacts with the atmosphere to influence climate. It's a mission that promises to
be, to quote the old saying, "worth its salt."

Improving Climate Forecasts

"We ultimately want to predict climate change and have greater confidence in our
predictions. Climate models are the only effective means we have to do so," said
Aquarius Principal Investigator Gary Lagerloef, a scientist at the Seattle-based
independent laboratory Earth & Space Research. "But, a climate model's forecast skill is
only as good as its ability to accurately represent modern-day observations."

Density-driven ocean circulation, according to Lagerloef, is controlled as much by
salinity as by ocean temperature. Sea salt makes up only 3.5 percent of the world's
ocean, but its relatively small presence reaps huge consequences.

Salinity influences the very motion of the ocean and the temperature of seawater,
because the concentration of sea salt in the ocean's surface mixed layer -- the portion of
the ocean that is actively exchanging water and heat with Earth's atmosphere -- is a
critical driver of these ocean processes. It's the missing variable in understanding the
link between the water cycle and ocean circulation. Specifically, it's an essential metric
to modeling precipitation and evaporation.

Accurate ocean surface salinity data are a necessary component to understanding what
will happen in the future, but can also open a window to Earth's climate past. When
researchers want to create a climate record that spans previous decades -- which helps
them identify trends -- it's necessary to collect and integrate data from the last two to
three decades to develop a consistent analysis.

"Aquarius, and successor missions based on it, will give us, over time, critical data that
will be used by models that study how Earth's ocean and atmosphere interact, to see
trends in climate," said Lagerloef. "The advances this mission will enable make this an
exciting time in climate research."

Taking Past Measurements with a Grain of Salt

Anyone who's splashed at the beach knows that ocean water is salty. Yet measuring
this simple compound in seawater has been a scientific challenge for well over a
century.

Until now, researchers had taken ocean salinity measurements from aboard ships,
buoys and aircraft – but they'd done so using a wide range of methods across assorted
sampling areas and over inconsistent times from one season to another. Because of the
sparse and intermittent nature of these salinity observations, researchers have not been
able to fine-tune models to obtain a true global picture of how ocean surface salinity is
influencing the ocean. Aquarius promises to resolve these deficiencies, seeing changes
in ocean surface salinity consistently across space and time and mapping the entire ice-
free ocean every seven days for at least three years.

The Age of Aquarius

Research modelers like William Large, an oceanographer at the National Center for
Atmospheric Research in Boulder, Colo., will use Aquarius' ocean surface salinity data,
along with precipitation and temperature observations, to round out the data needed to
refine the numerical climate models he and his colleagues have developed.

"This mission is sure to mark a new era for end users like us," explained Large.
"Aquarius puts us on the road to implementing a long-term, three-step plan that could
improve our climate models. The first step will be to use Aquarius data to identify if there
is a problem with our models -- what deficiencies exist, for example, in parts of the world
where observations are sparse.

"Second, the data will help us determine the source of these problems," Lange added.
"Salinity helps us understand density -- and density, after all, makes ocean waters sink
and float, and circulate around Earth.

"Third, Aquarius will help us solve the puzzle of what's going on in the ocean itself -- the
ocean processes," he added. "We'll pair an ocean observation experiment with the
satellite mission to explore the mixing and convection -- how things like salinity are
stirred in the ocean -- to better determine what processes might be actually changing
climate. Measuring salinity at the ocean surface will deliver a pioneering baseline of
observations for changes seen by the next generation of missions in the coming
decades."

"We've done all of the advance work leading up to the launch of Aquarius, so the proof
will be in the actual data," said Lagerloef. "Our intent is to put the data out immediately
as soon as the satellite begins transmitting. Before the end of the first year, we'll be
interpreting exactly what the data are telling us and how they will benefit climate
modeling."

For more information on Aquarius, visit: http://www.nasa.gov/aquarius .

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Tweetup at NASA's JPL Previews 2011 Missions

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

Veronica McGregor 818-354-9452
Jet Propulsion Laboratory, Pasadena, Calif.
veronica.c.mcgregor@jpl.nasa.gov

Stephanie L. Schierholz 202-358-4997
NASA Headquarters, Washington
stephanie.schierholz@nasa.gov

Advisory: 2011-168B June 1, 2011

Tweetup at NASA's JPL Previews 2011 Missions

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-168b&cid=release_2011-168b

PASADENA, Calif. -- NASA's Jet Propulsion Laboratory in Pasadena, Calif., will host a Tweetup on
Monday, June 6. More than 100 NASA Twitter followers, who registered in April, will attend the
event.

With four NASA/JPL space missions launching in 2011 and an asteroid belt encounter nearly
underway, this year will be one of the busiest ever in planetary exploration. Tweetup participants will
interact with JPL scientists and engineers about these upcoming missions: Aquarius, to study ocean
salinity; Grail, to study the moon's gravity field; Juno to Jupiter; and the Mars Science
Laboratory/Curiosity rover. Tweetup participants also will learn about the Dawn mission and its
planned encounter with the asteroid Vesta.

The Tweetup will take place from approximately 8 a.m. to 5:30 p.m. PDT. The event will be carried
live on http://www.ustream.tv/nasajpl2 , and portions will also be broadcast on NASA Television
from about 8:15 - 10:30 a.m. PDT and 1:30 - 3:30 p.m. PDT on June 6 at: http://www.nasa.gov/ntv .

The event will include a tour of JPL, hands-on demonstrations and a last chance to see the Curiosity
rover before it ships to Florida for its launch in the fall. Tour stops will include the Spacecraft
Assembly Facility, where Curiosity is undergoing assembly and testing, the mission control center of
NASA's Deep Space Network, and JPL's new Earth Science Center.

Tweetup participants will mingle with fellow attendees and the staff behind @NASA, @NASAJPL,
@MarsRovers, @AsteroidWatch and other NASA social media accounts.

NASA's first Tweetup was held at JPL on Jan. 21, 2009, and NASA Headquarters held its first on
July 21, 2009. The most recent event was at NASA's Kennedy Space Center for the space shuttle
Endeavour's final launch. Following JPL's June event, the next NASA Tweetup will be July 7-8 at
Kennedy for the Space Shuttle Program's final launch. Registration for that Tweetup is open from
noon EDT (9 a.m. PDT) Wednesday, June 1, through noon Thursday, June 2, at:
http://www.nasa.gov/tweetup .

WEB COVERAGE
Follow the conversation before and during the June 6 event on Twitter by using the hashtag
#NASATweetup and following the @NASAJPL, @JPLTweetup, and @NASATweetup accounts.

Find all the ways to connect and collaborate with NASA at: http://www.nasa.gov/connect .

For more information about Aquarius, Grail, Juno, the Curiosity rover, Dawn and NASA's other
science missions, visit: http://science.nasa.gov and http://www.jpl.nasa.gov .

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

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