New Mission Helps Offshore Industries Dodge Swirling Waters

Feature July 1, 2008


New Mission Helps Offshore Industries Dodge Swirling Waters

Hurricanes aren't the only hazards spinning up in the Gulf of Mexico -- they have a liquid
counterpart in the waters below called ocean eddies. Offshore industries, such as oil and
gas companies, have to keep a weather eye on both. In a worst-case scenario, they could
find themselves caught between the two. Satellite altimetry is helping government and
industry manage those risks.

Satellite ocean observations are a standard part of marine operations around the world.
Keeping track of local currents is critical for daily operations. And in the Gulf of Mexico,
that means knowing the location of the Loop Current and its dangerous eddies.

The Loop Current, which is part of the Gulf Stream, begins as a large flow of warm water
from the Caribbean. It heads up into the eastern part of the Gulf of Mexico, then turns
south and finally moves out through the Straits of Florida. Deep and fast moving, the
Loop Current often breaks off and forms strong, clockwise rotating eddies called
anticyclones that travel westward into the Gulf. The currents along the outer edges of the
Loop Current, as well as these eddies, have been clocked at speeds as high as three to
four knots (three to five miles per hour), comparable to the fastest ocean currents ever
observed.

Because the Loop Current and its eddies are warmer, and thus higher in surface elevation,
than the surrounding waters, they are easily spotted by satellite altimeters, such as those
aboard the NASA/French Space Agency Jason 1 and Ocean Surface Topography
Mission/Jason 2 satellites. To see what the altimeters see, many offshore operators turn to
Research Professor Robert Leben and his colleagues at the University of Colorado's
Center for Astrodynamics Research in Boulder. They use the latest satellite
measurements of sea-surface height from Jason 1 and two other satellite altimeters to
create maps showing the location, direction and speed of currents in the Gulf of Mexico.
Free and available on the center's Web site, these maps are used by a wide variety of
people involved in marine operations, along with scientists, fishermen and sailors. As
soon as measurements from the Ocean Surface Topography Mission/Jason 2 are
available, they will be included in the data sets as well.

For oil companies, knowing where the Loop Current and its eddies are and are likely to
go is critical. "The rate to rent a drilling rig in deep water is about $300,000 a day," said
George Forristall, of Forristall Ocean Engineering, Inc., Camden, Maine. "If you've
planned an operation and the current is too strong, you have to shut down and spend that
money without accomplishing anything. Once an oil field is found and a permanent
facility is built, it floats on the surface and connects to the bottom by pipes called risers.
You can protect those risers by streamlining them, but that costs a lot, too. Your riser
design has to be appropriate for the currents you expect at your site."

To plan and design rigs and oil platforms for the future, oil companies would like to be
able to anticipate the sea conditions a particular facility may encounter in the Gulf of
Mexico over its lifetime. A consortium of about 20 different companies, along with the
U.S. Minerals Management Service, has asked Leben and Forristall to develop a model
to help determine what the risks from strong currents may be.

"We're constructing a 1,000-year-long statistical simulation of the Loop Current and its
eddies," said Leben. "While we have only 20 to 30 years of observations, using
computer simulation and the right statistical methods, we can figure out how the current
and eddies behave and then simulate a longer period of time."

"It's a modeling technique called Monte Carlo simulation," he continued. "For example,
even if you don't know exactly how dice work, after a number of throws, you can figure
out the probabilities for certain numbers to appear."

"The idea," said Forristall, "is to map the Gulf. There are some places where there have
only been a few eddies in the past. With our artificial time series, we'll be able to fill in
the gaps. We'll be able to see what is the likelihood of an eddy occurring in a particular
spot."

Another goal of the effort is to better understand the relationship between the Loop
Current and hurricanes, which grow stronger as they pass over warm water. Leben said
results of the 1,000-year Loop Current simulation will be combined with simulations of
how the Loop Current's warm surface waters and eddies effect hurricane intensification.
"This will give us a way to assess the likelihood of warm Loop Current events and
intense hurricanes and plan for them."

"These tandem ocean/atmosphere events are rare, but they do occur," said Leben.
"During Hurricane Katrina, when both strong eddy currents and a category-five
hurricane hit the oil patch in the north-central Gulf of Mexico, a total of five rigs and 18
platforms were lost and many more were damaged."

Knowing more about the Loop Current and its spinning offspring will help oil companies
and other offshore industries plan for the future. "Nothing designed by man will ever be
perfectly safe from natural hazards," said Forristall, "but the better we understand the
environment, the better we will be able to manage risk at an acceptable cost."

For more information on OSTM/Jason 2, visit: http://www.nasa.gov/ostm .

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100 Years of Space Rock: The Tunguska Impact

Feature June 27, 2008



100 Years of Space Rock: The Tunguska Impact

At around 7:17 on the morning of June 30, 1908, a man based at the trading post at Vanavara in Siberia is
sitting on his front porch. In a moment, 40 miles from the center of an immense blast of unknown origin, he
will be hurled from his chair and the heat will be so intense he will feel as though his shirt is on fire. The
man at the trading post, and others in a largely uninhabited region of Siberia, near the Podkamennaya
Tunguska River, are to be accidental eyewitnesses to cosmological history.

"If you want to start a conversation with anyone in the asteroid business all you have to say is Tunguska,"
said Don Yeomans, manager of the Near-Earth Object Office at NASA's Jet Propulsion Laboratory. "It is
the only entry of a large meteoroid we have in the modern era with first-hand accounts."

While the impact occurred in '08, the first scientific expedition to the area would have to wait for 19 years.
In 1921, Leonid Kulik, the chief curator for the meteorite collection of the St. Petersburg museum led an
expedition to Tunguska. But the harsh conditions of the Siberian outback thwarted his team's attempt to
reach the area of the blast. In 1927, a new expedition, again lead by Kulik, reached its goal.

"At first, the locals were reluctant to tell Kulik about the event," said Yeomans. "They believed the blast
was a visitation by the god Ogdy, who had cursed the area by smashing trees and killing animals."

While testimonials may have at first been difficult to obtain, there was plenty of evidence lying around.
Eight hundred square miles of remote forest had been ripped asunder. Eighty million trees were on their
sides, lying in a radial pattern.

"Those trees acted as markers, pointing directly away from the blast's epicenter," said Yeomans. "Later,
when the team arrived at ground zero, they found the trees there standing upright -- but their limbs and bark
had been stripped away. They looked like a forest of telephone poles."

Such debranching requires fast moving shock waves that break off a tree's branches before the branches can
transfer the impact momentum to the tree's stem. Thirty seven years after the Tunguska blast, branchless
trees would be found at the site of another massive explosion -- Hiroshima, Japan.

Kulik's expeditions (he traveled to Tunguska on three separate occasions) did finally get some of the locals
to talk. One was the man based at the Vanara trading post who witnessed the heat blast as he was launched
a few yards. His account:

Suddenly in the north sky… the sky was split in two, and high above the
forest the whole northern part of the sky appeared covered with fire…
At that moment there was a bang in the sky and a mighty crash… The
crash was followed by a noise like stones falling from the sky, or of
guns firing. The earth trembled.

The massive explosion packed a wallop. The resulting seismic shockwave registered with sensitive
barometers as far away as England. Dense clouds formed over the region at high altitudes which reflected
sunlight from beyond the horizon. Night skies glowed, and reports came in that people who lived as far
away as Asia could read newspapers outdoors as late as midnight. Locally, hundreds of reindeer, the
livelihood of local herders, were killed, but there was no direct evidence that any person perished in the
blast.

"A century later some still debate the cause and come up with different scenarios that could have caused the
explosion," said Yeomans. "But the generally agreed upon theory is that on the morning of June 30, 1908, a
large space rock, about 120 feet across, entered the atmosphere of Siberia and then detonated in the sky."

It is estimated the asteroid entered Earth's atmosphere traveling at a speed of about 33,500 miles per hour.
During its quick plunge, the 220-million-pound space rock heated the air surrounding it to 44,500 degrees
Fahrenheit. At 7:17 a.m. (local Siberia time), at a height of about 28,000 feet, the combination of pressure
and heat caused the asteroid to fragment and annihilate itself, producing a fireball and releasing energy
equivalent to about 185 Hiroshima bombs.

"That is why there is no impact crater," said Yeomans. "The great majority of the asteroid is consumed in
the explosion."

Yeomans and his colleagues at JPL's Near-Earth Object Office are tasked with plotting the orbits of
present-day comets and asteroids that cross Earth's path, and could be potentially hazardous to our planet.

Yeomans estimates that, on average, a Tunguska-sized asteroid will enter Earth's atmosphere once every
300 years. On this 100th anniversary of the Tunguska event, does that mean we have 200 years of largely
meteor-free skies?

"Not necessarily," said Yeomans. "The 300 years between Tunguska-sized events is an average based on
our best science. I think about Tunguska all the time from a scientific point of view, but the thought of a
another Tunguska does not keep me up at night."

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Mars Odyssey THEMIS Images: June 16-27, 2008

MARS ODYSSEY THEMIS IMAGES
June 16-27, 2008

o Clouds (Released 16 June 2008)

http://themis.asu.edu/zoom-20080616a

o Channel and Graben (Released 17 June 2008)

http://themis.asu.edu/zoom-20080617a

o Collapse (Released 18 June 2008)

http://themis.asu.edu/zoom-20080618a

o Lava Channel (Released 19 June 2008)

http://themis.asu.edu/zoom-20080619a

o Polar Dunes (Released 20 June 2008)

http://themis.asu.edu/zoom-20080620a

o Polar Dunes (Released 23 June 2008)

http://themis.asu.edu/zoom-20080623a

o Mix of Textures (Released 24 June 2008)

http://themis.asu.edu/zoom-20080624a

o Lyot Crater Dunes (Released 25 June 2008)

http://themis.asu.edu/zoom-20080625a

o Olympus Mons (Released 26 June 2008)

http://themis.asu.edu/zoom-20080626a

o Cerulli Channels (Released 27 June 2008)

http://themis.asu.edu/zoom-20080627a

All of the THEMIS images are archived here:

http://themis.asu.edu/latest.html

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission
for NASA's Office of Space Science, Washington, D.C. The Thermal Emission
Imaging System (THEMIS) was developed by Arizona State University,
Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing.
The THEMIS investigation is led by Dr. Philip Christensen at Arizona State
University. Lockheed Martin Astronautics, Denver, is the prime contractor
for the Odyssey project, and developed and built the orbiter. Mission
operations are conducted jointly from Lockheed Martin and from JPL, a
division of the California Institute of Technology in Pasadena.

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MRO HiRISE Images - June 25, 2008

MARS RECONNAISSANCE ORBITER HIRISE IMAGES
June 25, 2008

o Polygons, Crater Layers, and Defrosting Dunes

http://hirise.lpl.arizona.edu/PSP_008426_2595

o Layers at Margin of Hellas Impact Basin

http://hirise.lpl.arizona.edu/PSP_008387_1510

o Indicators of Recent Winds on Mars

http://hirise.lpl.arizona.edu/PSP_007153_2505

o Volcanic and Clay Materials Near Nili Fossae

http://hirise.lpl.arizona.edu/PSP_007055_2015

o A Crater Superposed on Chaotic Terrain Near the
Head of a Dao Vallis Branch

http://hirise.lpl.arizona.edu/PSP_005881_1465

All of the HiRISE images are archived here:

http://hirise.lpl.arizona.edu/

Information about the Mars Reconnaissance Orbiter is online at

http://www.nasa.gov/mro. The mission is managed by NASA's Jet Propulsion
Laboratory, a division of the California Institute of Technology, for the NASA
Science Mission Directorate, Washington, D.C. Lockheed Martin Space Systems,
of Denver, is the prime contractor and built the spacecraft. HiRISE is operated by t
he University of Arizona. Ball Aerospace and Technologies Corp., of Boulder, Colo.,
built the HiRISE instrument.

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Cassini to Earth: 'Mission Accomplished, But New Questions Await!'

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

Carolina Martinez 818-354-9382
Jet Propulsion Laboratory, Pasadena, Calif.
carolina.martinez@jpl.nasa.gov

NEWS RELEASE: 2008-122 June 27, 2008

Cassini to Earth: 'Mission Accomplished, But New Questions Await!'

PASADENA, Calif.—NASA's Cassini mission is closing one chapter of its journey at Saturn and
embarking on a new one with a two-year mission that will address new questions and bring it
closer to two of its most intriguing targets—Titan and Enceladus.

On June 30, Cassini completes its four-year prime mission and begins its extended mission,
which was approved in April of this year.

Among other things, Cassini revealed the Earth-like world of Saturn's moon Titan and showed
the potential habitability of another moon, Enceladus. These two worlds are primary targets in
the two-year extended mission, dubbed the Cassini Equinox Mission. This time period also will
allow for monitoring seasonal effects on Titan and Saturn, exploring new places within Saturn's
magnetosphere, and observing the unique ring geometry of the Saturn equinox in August of 2009
when sunlight will pass directly through the plane of the rings.

"We've had a wonderful mission and a very eventful one in terms of the scientific discoveries
we've made, and yet an uneventful one when it comes to the spacecraft behaving so well," said
Bob Mitchell, Cassini program manager at NASA's Jet Propulsion Laboratory, Pasadena,
Calif. "We are incredibly proud to have completed all of the objectives we set out to accomplish
when we launched. We answered old questions and raised quite a few new ones and so our
journey continues."

A new addition to the Cassini science team is Bob Pappalardo who will step into the role of
Cassini Project Scientist in July, taking over for Dennis Matson, a multi-year veteran on the
project who will be working on future flagship mission studies to the outer solar system. "I am
honored and humbled to be able to work with such a scientifically rich mission, and with the
outstanding scientists and engineers who are the backbone of Cassini," said Pappalardo.

Pappalardo is a geologist whose research focuses on processes that have shaped the icy moons of
the outer solar system, including processes that power the geysers of Saturn's moon Enceladus.
He received his bachelor's degree from Cornell University, Ithaca, N.Y., and his Ph.D. in
geology from Arizona State University, Tempe. He worked with the Galileo imaging team while
a Postdoctoral Researcher at Brown University, Providence, RI. Prior to joining JPL in 2006, he
was an assistant professor of planetary sciences at the University of Colorado at Boulder.
Currently he resides in Venice, Calif. More information on Pappalardo is at

http://science.jpl.nasa.gov/people/Pappalardo .

Cassini launched Oct. 15, 1997, from Cape Canaveral, Fla., on a seven-year journey to Saturn,
traversing 3.5 billion kilometers (2.2 billion miles). The mission entered Saturn's orbit on June
30, 2004, and began returning stunning data of Saturn's rings almost immediately. The spacecraft
is extremely healthy and carries 12 instruments powered by three radioisotope thermoelectric
generators. Data from Cassini's nominal and extended missions could lay the groundwork for
possible future missions to Saturn, Titan or Enceladus.

Information about the Cassini Equinox Mission is at http://www.nasa.gov/cassini and

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

The Cassini Equinox 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 mission for NASA's Science Mission Directorate,
Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

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Phoenix Returns Treasure Trove for Science

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

Sara Hammond 520-626-1974
University of Arizona, Tucson
shammond@lpl.arizona.edu

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

News Release: 2008-121 June 26, 2008

Phoenix Returns Treasure Trove for Science

NASA's Phoenix Mars Lander performed its first wet chemistry experiment
on Martian soil flawlessly yesterday, returning a wealth of data that for Phoenix
scientists was like winning the lottery.

"We are awash in chemistry data," said Michael Hecht of NASA's Jet
Propulsion Laboratory, lead scientist for the Microscopy,
Electrochemistry and Conductivity Analyzer, or MECA, instrument on
Phoenix. "We're trying to understand what is the chemistry of wet soil
on Mars, what's dissolved in it, how acidic or alkaline it is. With the
results we received from Phoenix yesterday, we could begin to tell what
aspects of the soil might support life."

"This is the first wet-chemical analysis ever done on Mars or any
planet, other than Earth," said Phoenix co-investigator Sam Kounaves of Tufts
University, science lead for the wet chemistry investigation.

About 80 percent of Phoenix's first, two-day wet chemistry experiment is
now complete. Phoenix has three more wet-chemistry cells for use later
in the mission.

"This soil appears to be a close analog to surface soils found in the
upper dry valleys in Antarctica," Kouvanes said. "The alkalinity of the
soil at this location is definitely striking. At this specific location,
one-inch into the surface layer, the soil is very basic, with a pH of
between eight and nine. We also found a variety of components
of salts that we haven't had time to analyze and identify yet, but that
include magnesium, sodium, potassium and chloride."

"This is more evidence for water because salts are there. We also found
a reasonable number of nutrients, or chemicals needed by life as we know
it," Kounaves said. "Over time, I've come to the conclusion that the amazing
thing about Mars is not that it's an alien world, but that in many
aspects, like mineralogy, it's very much like Earth."

Another analytical Phoenix instrument, the Thermal and Evolved-Gas
Analyzer (TEGA), has baked its first soil sample to 1,000 degrees
Celsius (1,800 degrees Fahrenheit). Never before has a soil sample from
another world been baked to such high heat.

TEGA scientists have begun analyzing the gases released at a range of
temperatures to identify the chemical make-up of soil and ice. Analysis
is a complicated, weeks-long process.

But "the scientific data coming out of the instrument have been just
spectacular," said Phoenix co-investigator William Boynton of the
University of Arizona, lead TEGA scientist.

"At this point, we can say that the soil has clearly interacted with
water in the past. We don't know whether that interaction occurred in
this particular area in the northern polar region, or whether it might
have happened elsewhere and blown up to this area as dust."

Leslie Tamppari, the Phoenix project scientist from JPL, tallied what Phoenix
has accomplished during the first 30 Martian days of its mission, and
outlined future plans.

The Stereo Surface Imager has by now completed about 55 percent of its
three-color, 360-degree panorama of the Phoenix landing site, Tamppari
said. Phoenix has analyzed two samples in its optical microscope as well as
first samples in both TEGA and the wet chemistry laboratory. Phoenix has
been collecting information daily on clouds, dust, winds, temperatures
and pressures in the atmosphere, as well as taking first nighttime
atmospheric measurements.

Lander cameras confirmed that white chunks exposed during trench digging
were frozen water ice because they sublimated, or vaporized, over a few
days. The Phoenix robotic arm dug and sampled, and will continue to dig and
sample, at the 'Snow White' trench in the center of a polygon in the
polygonal terrain.

"We believe this is the best place for creating a profile of the surface
from the top down to the anticipated icy layer," Tamppari said. "This is
the plan we wanted to do when we proposed the mission many years ago.
We wanted a place just like this where we could sample the soil down to
the possible ice layer."

The Phoenix mission is led by Peter Smith of The University of Arizona
with project management at JPL and development partnership at Lockheed
Martin, located in Denver. International contributions come from the
Canadian Space Agency; the University of Neuchatel, Switzerland; the
universities of Copenhagen and Aarhus, Denmark; Max Planck Institute,
Germany; and the Finnish Meteorological Institute. For more information
on the Phoenix mission, link to http://www.nasa.gov/phoenix and
http://phoenix.lpl.arizona.edu.

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NASA's Phoenix Mars Lander Puts Soil in Chemistry Lab, Team Discusses Next Steps

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

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

Sara Hammond 520-626-1974
University of Arizona, Tucson
shammond@lpl.arizona.edu

NEWS RELEASE: 2008-120 June 25, 2008

NASA's Phoenix Mars Lander Puts Soil in Chemistry Lab, Team Discusses Next Steps

TUCSON, Ariz. -- NASA's Phoenix Mars Lander placed a sample of Martian soil in the
spacecraft's wet chemistry laboratory today for the first time. Results from that
instrument, part of Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer,
are expected to provide the first measurement of the acidity or alkalinity of the planet's
soil.

The analysis of this soil sample and others will help researchers determine whether ice
beneath the soil ever has melted, and whether the soil has other qualities favorable for
life.

The Phoenix team is discussing what sample to deliver next to the lander's other
analytical instrument, which bakes and sniffs soil to identify volatile ingredients.
Engineers have identified possible problems in the mechanical and electrical operation of
that instrument, the Thermal and Evolved-Gas Analyzer, or TEGA.

Scientists are studying information provided by TEGA's analysis of the first Martian soil
sample put in that instrument. The instrument has eight single-use oven cells; each cell
can analyze one sample. When doors for a second TEGA oven were commanded open
last week, the doors opened only partway. Later, the team determined that mechanical
interference may prevent doors on that oven and three others from opening fully. The
remaining three ovens are expected to have one door that opens fully and one that opens
partially, as was the case with the first oven used.

"The tests we have done in our test facility during the past few days show the robotic arm
can deliver the simulated Martian soil through the opening with the doors in this
configuration," said William Boynton of the University of Arizona, Tucson, lead scientist
for TEGA. "We plan to save the cells where doors can open wider for accepting ice
samples."

Scientists believe the first soil sample delivered to TEGA was so clumpy that soil
particles clogged a screen over the opening. Four days of vibration eventually succeeded
at getting the soil through the screen. However, engineers believe the use of a motor to
create the vibration may also have caused a short circuit in wiring near that oven.
Concern about triggering other short circuits has prompted the Phoenix team to be
cautious about the use of other TEGA oven cells.

Subsequent soil samples for TEGA will be delivered with a different method than the
first. The new method will sprinkle soil into the instrument to make it easier for particles
to get through the screens.

The Phoenix mission is led by Peter Smith at the University of Arizona with project
management at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the
development partnership at Lockheed Martin in Denver. International contributions are
from the Canadian Space Agency; the University of Neuchatel, Switzerland; the
universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and
the Finnish Meteorological Institute.

For more about Phoenix, visit: http://www.nasa.gov/phoenix and

http://phoenix.lpl.arizona.edu.

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NASA Mission to Answer Lingering Questions From Deep Blue Sea

Feature June 25, 2008


NASA Mission to Answer Lingering Questions From Deep Blue Sea

Ocean tides and currents across the globe still hold within their watery grasp the key to
unanswered questions about our planet.

Scientists hope the new follow-on mission to the Jason 1 and Topex/Poseidon satellite
missions, equipped with the latest high-tech instruments, will bring them closer to
answering broad fundamental questions: How does ocean circulation vary from season to
season, from year to year and from decade to decade? How much can the ocean change
from natural and human-induced causes? In what ways does the ocean impact human
activities?

The answers are essential when we consider that oceans cover 70 percent of Earth's
surface. Their contents feed billions of humans and animals alike, support whole
industries, and are the source of the rain and snow that feed the world's freshwater
supply. The newly launched Ocean Surface Topography Mission/Jason 2 is poised to
help scientists answer these and other critical scientific questions about ocean
phenomena.

The mission, OSTM/Jason 2 for short, is set to transform what we know about some of
the prevailing weather and climate patterns driven by changes in oceanic tides and
currents.

With Topex/Poseidon and Jason 1, NASA has measured the height of the ocean
surface—more commonly known as sea level—with an accuracy of better than one inch
(2.5 centimeters) from an orbiting altitude of 830 miles (1,336 kilometers). This is
comparable to measuring the thickness of a sheet of paper on the ground from the altitude
of a commercial airliner. Sea level varies greatly over the world's oceans and is not a
constant. Scientists want to learn more about how its fluctuations are related to ocean
circulation, climate change, marine weather, flooding, drought, hurricane intensity and
coastline erosion. The more scientists learn about ocean surface topography, as they will
with OSTM/Jason 2, the better they can apply that knowledge to answer the remaining
mysteries of the oceans.

Scientists know that Earth's climate system has experienced changes throughout its
history. A record of ocean surface topography observations reflecting some of those
changes exists for the last 15 years, thanks to Topex/Poseidon and Jason 1. However,
this period accounts for relatively few moments in the planet's long history.

"The scientific community desperately needs much longer measurement records to begin
to understand year-to-year and decade-to-decade changes in the ocean system," said
OSTM/Jason 2 science team member Carl Wunsch, a professor at the Massachusetts
Institute of Technology in Cambridge, Mass. "Of course, ultimately, our descendants
will need to understand century-to-century and longer variability."

Scientists expect the mission's altimeters to offer added insight into ocean surface
topography when combined with the accomplishments of the previous two missions.
Mean sea level is an indicator of the amount of heat contained in a column of water from
the ocean surface to the ocean floor. That heat is like the driver of a huge underwater
truck that affects ocean currents as it goes. With the longer-term measurements to be
captured by this new mission, scientists will be more in-tune with where the "driver" is
going and why, how it interacts with other forces like wind and rain, and what may
happen in the wake of changes in its route.

"OSTM/Jason 2 will provide a unique data history of sea level rise that will allow us to
answer questions about the effects of global warming," said the mission's science team
member Dudley Chelton of Oregon State University in Corvalis, Ore. "This mission
will also provide insight into the reason why most of the climate models underestimate
the rate of sea level rise. This may be an indication that these models are
underestimating other symptoms of global warming as well."

Less than four percent of ocean waters remain unaffected by humans. Through shipping,
fishing, sewage and fertilizer run-off, pollution, oil spills, and auto and factory
emissions, human activities are changing the chemistry of our oceans. Some of that
human-induced change is combined with natural events that can also impact ocean
temperatures, salinity, acidity and air pressure to influence sea surface height.

Just as humans affect oceans, oceans and related sea level likewise affect humans.
Changes in sea level, like the incremental rises reported in recent years, can cause erosion
of populated coastal areas, freshwater shortages, and disruption of the salt-water balance
that can affect the seafood that feeds people all over the world.

With more thorough foresight into ocean circulation, specifically surface ocean currents,
the fishing industry can reduce fuel costs by mapping more efficient sailing routes that
consider the direction and speed of the oceans' course. Chelton believes that OSTM/Jason
2 will also lead to improved understanding of oceanic eddies and unexpected movements
of jet-like ocean currents. "There is substantial evidence that these eddies play important
roles in the fluctuation of the oceans' heat, momentum and various water properties," he
said.

"Without this next generation of altimeters, there's almost no hope of ever understanding
what is going on and what could happen," said Wunsch. "This new ocean surface topography
mission is precisely what is needed as a next step in telling the oceans' story. With the
technology this mission affords us and the information we can gain from it, we can take more
action to enhance quality of life and protect the bodies of water that sustain us."

For more information on OSTM/Jason 2 on the Web, visit: http://www.nasa.gov/ostm .

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NASA Spacecraft Reveal Largest Crater in Solar System

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

Steve Cole 202-358-0918
Headquarters, Washington
stephen.e.cole@nasa.gov

David Chandler 617-253-2704
Massachusetts Institute of Technology, Cambridge
dlc1@mit.edu

NEWS RELEASE: 2008-119 June 25, 2008

NASA Spacecraft Reveal Largest Crater in Solar System

PASADENA, Calif. -- New analysis of Mars' terrain using NASA spacecraft observations
reveals what appears to be by far the largest impact crater ever found in the solar system.

NASA's Mars Reconnaissance Orbiter and Mars Global Surveyor have provided detailed
information about the elevations and gravity of the Red Planet's northern and southern
hemispheres. A new study using this information may solve one of the biggest remaining
mysteries in the solar system: Why does Mars have two strikingly different kinds of terrain in its
northern and southern hemispheres? The huge crater is creating intense scientific interest.

The mystery of the two-faced nature of Mars has perplexed scientists since the first
comprehensive images of the surface were beamed home by NASA spacecraft in the 1970s. The
main hypotheses have been an ancient impact or some internal process related to the planet's
molten subsurface layers. The impact idea, proposed in 1984, fell into disfavor because the
basin's shape didn't seem to fit the expected round shape for a crater. The newer data is
convincing some experts who doubted the impact scenario.

"We haven't proved the giant-impact hypothesis, but I think we've shifted the tide," said Jeffrey
Andrews-Hanna, a postdoctoral researcher at the Massachusetts Institute of Technology in
Cambridge.

Andrews-Hanna and co-authors Maria Zuber of the Massachusetts Institute of Technology, and
Bruce Banerdt of NASA's Jet Propulsion Laboratory in Pasadena, Calif., report the new findings
in the journal Nature this week.

A giant northern basin that covers about 40 percent of Mars' surface, sometimes called the
Borealis basin, is the remains of a colossal impact early in the solar system's formation, the new
analysis suggests. At 8,500 kilometers (5,300 miles) across, it is about four times wider than the
next-biggest impact basin known, the Hellas basin on southern Mars. An accompanying report
calculates that the impacting object that produced the Borealis basin must have been about 2,000
kiolometers (1,200 miles) across. That's larger than Pluto.

"This is an impressive result that has implications not only for the evolution of early Mars, but
also for early Earth's formation," said Michael Meyer, the Mars chief scientist at NASA
Headquarters in Washington.

This northern-hemisphere basin on Mars is one of the smoothest surfaces found in the solar
system. The southern hemisphere is high, rough, heavily cratered terrain, which ranges from 4 to
8 kilometers (2.5 to 5 miles) higher in elevation than the basin floor.

Other giant impact basins have been discovered that are elliptical rather than circular. But it took
a complex analysis of the Martian surface from NASA's two Mars orbiters to reveal the clear
elliptical shape of Borealis basin, which is consistent with being an impact crater.

One complicating factor in revealing the elliptical shape of the basin was that after the time of
the impact, which must have been at least 3.9 billion years ago, giant volcanoes formed along
one part of the basin rim and created a huge region of high, rough terrain that obscures the
basin's outlines. It took a combination of gravity data, which tend to reveal underlying structure,
with data on current surface elevations to reconstruct a map of Mars elevations as they existed
before the volcanoes erupted.

"In addition to the elliptical boundary of the basin, there are signs of a possible second, outer ring
-- a typical characteristic of large impact basins," Banerdt said.

JPL manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate,
Washington. For more information about the mission, visit: http://www.nasa.gov/mro .

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New NASA Website Focuses on Global Climate Change

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 / Diya Chacko 818-393-5464
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.D.Buis@jpl.nasa.gov
dschacko@jpl.nasa.gov

INTERNET ADVISORY: 2008-116 June 23, 2008

New NASA Website Focuses on Global Climate Change

A new website from NASA's Jet Propulsion Laboratory, Pasadena, Calif., is devoted to
educating the public about Earth's changing climate. The Global Climate Change website
provides easy-to-understand information about the causes and effects of climate change
and how NASA studies it.

The new Global Climate Change website may be found at: http://climate.jpl.nasa.gov .

Highlights of the new website include:

* A continuously updated snapshot of our planet's health, built from NASA data on
such climate indicators as the condition of Earth's ice sheets, global average
temperatures, sea level change and concentrations of key greenhouse gases.

* Interactive visualizations of current climate data, including a Sea Level Viewer
that provides views from space of ocean surface topography data and related
phenomena such as El Nin?o; and a Global Climate Change Time Machine that
takes users back in time to see how Earth's climate has changed in the past, and
how it is projected to change in the future.

* A downloadable desktop widget that allows users to track key indicators of
climate change as measured by NASA satellites.

* Easy-to-understand background articles on the evidence, causes and effects, and
uncertainties of global climate change, as well as links to selected resources that
provide information about possible solutions.

* NASA's Eyes on the Earth: An overview of ongoing NASA JPL missions to study
our planet's oceans, atmosphere, land, ice and biosphere.

* The latest news and features from NASA JPL on climate change research.

For more information on NASA's Earth Science Program, visit: http://www.nasa.gov.

JPL studies all aspects of the Earth system -- our oceans, land, atmosphere, biosphere,
and cryosphere -- to identify how Earth's climate is changing, understand the causes of
these changes, and support development of models used to predict future global change.
Currently, JPL has six dedicated Earth science spacecraft in orbit, with another five
instruments flying aboard NASA's Terra, Aqua and Aura spacecraft. JPL's newest Earth
mission, the Ocean Surface Topography Mission/Jason 2, launched June 20. Several
more missions are planned for launch in the next few years, including the Orbiting
Carbon Observatory, scheduled for launch in January 2009. Decision makers around the
world use JPL Earth science data to support policy-making and resource management
decisions.

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

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