Send in the Clouds

Feature August 09, 2010


Send in the Clouds

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-262&cid=release_2010-262

Gaze up at a cloud-filled sky, and you may spot the white, fluffy shape of a dragon, fish
or elephant. Looking at the same sky, Graeme Stephens sees a different vision -- a
possible future for Earth's climate.

Stephens, a professor at Colorado State University in Ft. Collins, is principal
investigator of NASA's CloudSat mission, launched in 2006 to improve our
understanding of the role clouds play in our complicated climate system. Stephens
says that as Earth's global temperature continues to rise, water vapor -- the most
abundant greenhouse gas on Earth, which traps heat much as carbon dioxide does --
will continue to build, with uncertain results.

"We're seeing that now," Stephens said. "We just don't know what this will mean for
how clouds might change, and for Earth's temperature and climate. Although a small
change of clouds--for example, more low clouds--in the right direction would mitigate
the effects of increased carbon dioxide, a small change of clouds in a different
direction--for example, more high clouds--would amplify the warming caused by
increasing carbon dioxide."

Calculating the balance between the cooling or warming effect of clouds and the
warming effect of greenhouse gases is a complex problem for researchers, given their
current understanding of clouds on Earth. And it's just one of many questions
Stephens and fellow scientists are working to address with observations from
CloudSat, an experimental satellite built and managed by NASA's Jet Propulsion
Laboratory, Pasadena, Calif. CloudSat's goal is to learn about clouds and their effect
on climate by studying them from space.

Floating Facts of Life

Clouds are an inescapable, and necessary, part of life. Aside from making for
spectacular sunsets, they also create weather as we know it, from drizzly spring
afternoons to the dark, dreary days of winter. "In all ways, shapes and forms, clouds
influence life on Earth -- including our climate," says Stephens.

They also play a major role in making Earth habitable. As the sun's rays shine on our
planet, flat, low-altitude stratus clouds reflect most of this heat back into space, keeping
Earth cool with their shade. At the same time, thin, wide cirrus clouds high in the
atmosphere trap heat on Earth's surface, keeping the planet warm. This delicate
balance helps to create a comfortable climate, where life flourishes.

Clouds also play a primary role in how life-giving water circulates around our planet.
As water on Earth's surface heats, it evaporates into water vapor and rises. As this
vapor cools in the atmosphere, the molecules begin to clump together around stray
particulates and condense to form clouds. When the clumps become too big, they drop
back onto Earth's surface in the form of rain or snow. The never-ending global process
of evaporation, precipitation, freezing and melting circulates water around the world --
while also providing the freshwater we need to live. This cycle, which is closely linked
to natural exchanges of energy among the atmosphere, ocean and land, helps define
our climate.

It's difficult to say what our world would be like if there were no clouds. But, says
Stephens, "It's certain that our world without clouds would be nothing like what we
know today."

Mars: A World Without Clouds (Mostly)

In fact, it might be much like Mars, says JPL planetary scientist David Kass. The Red
Planet today has relatively few clouds compared to Earth. That's because the Martian
atmosphere contains less than a tenth of a percent of the amount of water vapor found
in Earth's atmosphere. Without much water vapor, and with temperatures averaging 80
degrees Celsius (176 degrees Fahrenheit) colder than on Earth, only thin ice clouds
form. They tend to look like a thinner version of Earth's wispy cirrus clouds.

"We don't think that clouds on Mars get to the point where you couldn't see the sun
through them, but they might get thick enough that you could look at the sun through
them without hurting your eyes," sats Kass.

Mars also has thicker clouds made of frozen carbon dioxide -- commonly called dry ice
--that form both high in the atmosphere and at the poles during winter, where the sun
never rises for half the Mars year. These clouds are dense enough to dim the sun's
light by about 40 percent (although the polar clouds are never actually illuminated by
the sun), but because they are found only in limited regions near the planet's poles
and equator, they are unlikely to affect the Martian climate as a whole.

Scientists theorize that the relatively sparse clouds on Mars allow temperatures to rise
and fall dramatically. Without the cooling effect of significant cloud shade or the
insulating effect of thick cloud blankets, the surface of Mars heats drastically during
the day -- reaching temperatures around 18 degrees Celsius (65 degrees Fahrenheit)
at the equator -- before the temperature plummets at night -- to equatorial surface
temperatures as cold as 130 degrees Celsius below freezing (minus 202 degrees
Fahrenheit).

But researchers don't yet know for certain how exactly Martian clouds affect the
planet's climate. "It's not clear yet how big a role clouds play in Mars' climate," says
Kass. "This is really on the cutting edge right now." As planetary climate models
become more sophisticated, they will include the radiative effects of the clouds seen in
data from the Mars Climate Sounder on NASA's Mars Reconnaissance Orbiter. Kass
says the modelers will be able to incorporate that data and examine cases with and
without clouds to see their impacts. "We hope to know more soon," Kass adds.

Venus: A Greenhouse Girl Gone Wild

If Mars is what an Earth without many clouds might look like, then Venus shows what
our world might look like with far more.

Venus' skies are stuffed with brilliant white clouds that stretch around the entire planet
without a single break. As a result, they -- and other molecules in the atmosphere --
reflect more than 80 percent of the sun's light back out into space. For many years,
planetary scientists thought this would keep the surface of Venus relatively cool. Yet
when the Russian probe Venera 4 landed on the Venusian surface in 1967, it
measured a temperature of 482 degrees Celsius (900 degrees Fahrenheit). That's hot
enough to melt lead.

"At that point, we realized two things: Venus' atmosphere is very thick -- about 100
times thicker than Earth's -- and greenhouse gases are important to climates," said
Kevin Baines, a planetary scientist at JPL and senior research scientist at the
University of Wisconsin-Madison.

Venus' thick clouds are surrounded by carbon dioxide, a greenhouse gas that traps
heat on the planet's surface. The little heat from the sun that makes it through the
reflective cloud barrier has little chance of escape, and as that heat builds -- if only a
little bit at a time -- the surface of Venus gets hotter and hotter.

The heating of Venus' clouds could also cause the planet's extreme air circulation.
The excess heat, Baines says, seems to whip the entire atmosphere up to hurricane-
force winds, causing the atmosphere at cloud level to circulate 60 times faster than the
planet rotates.

"Venus is a planet of extremes," says Baines. "It's very hostile and very hot; you can't
survive very long there."

Titan: Partly Cloudy, With a Chance of Methane Rain

There is a middle ground between Mars' relatively clear skies and Venus' cloud-
choked heavens. Scattered clouds float above the icy surface and liquid lakes of Titan,
the largest of Saturn's many moons. These clouds, which are made mostly of
methane, punctuate the sky more in the winter than in the summer, just like clouds on
Earth. By trapping in the little heat that makes it through Titan's upper level of thicker
atmospheric clouds, the scattered clouds warm the surface to a frigid minus 183
degrees Celsius (minus 297 degrees Fahrenheit) on average, keeping the moon's
methane lakes and rivers liquid.

NASA's Cassini-Huygens spacecraft studies Titan and its climate, in part to learn more
about how cloud cover and other variables affect climate.

CloudSat: Revealing the Inner Secrets of Earth's Clouds

So what have the first four years of CloudSat operations taught us about our
mysterious friends in the sky? Stephens says the mission has already yielded a
number of important findings.

Among the highlights, the satellite has gathered the first statistics on global vertical
cloud structure, including overlapping clouds, to create three-dimensional maps of
Earth's cloud cover. It measured the percentage of clouds giving off rain at any given
time (13 percent) to better understand how efficiently clouds convert condensed water
into rain. It has monitored nighttime storms at Earth's poles from space for the first
time. And it has revealed connections between storms at the poles and very high
clouds that help create ozone.

"Before CloudSat, we essentially had photos of the tops of clouds from other satellites
and photos of the bottoms of clouds from ground-based telescopes," says Deborah
Vane, CloudSat deputy principal investigator and JPL project manager for the mission.
"CloudSat's advanced radar slices into clouds and looks into their inner structure."

By viewing this complete picture of how clouds operate both inside and out for the first
time, and monitoring it on a global scale, CloudSat is offering climatologists the data
they need to create better models of Earth's climate -- and help predict what the
surface of our planet will probably look like in the future.

So could Earth ultimately turn into a steady inferno like Venus or a fluctuating icebox
like Mars? Fortunately, says Stephens, data from CloudSat and other sources show
that Earth's clouds are not about to shrink drastically or engulf our skies anytime soon.

"With CloudSat, we're getting information that's critical to understanding how changes
to clouds will ultimately take place," said Stephens. "If we can confirm that the
assumptions climate models make are right -- or wrong -- then we can have a major
influence on their ability to predict the future."

For more information on CloudSat, visit: http://cloudsat.atmos.colostate.edu/ and
http://www.nasa.gov/cloudsat .

#2010-262

-END-

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

Written by Kelen Tuttle

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=pwL7KjMWKlL6JuJ&s=iiLYL1PFIeIKJ0MLIsE&m=ckJPJ8MOKaLNKfI

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=khKXI4OCLhIOK6J&s=iiLYL1PFIeIKJ0MLIsE&m=ckJPJ8MOKaLNKfI

NASA and ESA's First Joint Mission to Mars Selects Instruments

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

Jorge Vago 31-71-5655211
European Space Agency, The Netherlands
jorge.vago@esa.int

NEWS RELEASE: 2010-254 Aug. 2, 2010

NASA AND ESA'S FIRST JOINT MISSION TO MARS SELECTS INSTRUMENTS

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-254&cid=release_2010-254

PASADENA, Calif. -- NASA and the European Space Agency (ESA) have embarked on a joint
program to explore Mars in the coming decades and selected the five science instruments for the first
mission.

The principal investigator for one of the instruments, and the management for NASA's roles in the
mission, are based at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The ExoMars Trace Gas Orbiter, scheduled to launch in 2016, is the first of three joint robotic missions
to the Red Planet. It will study the chemical makeup of the Martian atmosphere with a 1000-fold
increase in sensitivity over previous Mars orbiters. The mission will focus on trace gases, including
methane, which could be potentially geochemical or biological in origin and be indicators for the
existence of life on Mars. The mission also will serve as an additional communications relay for Mars
surface missions beginning in 2018.

"Independently, NASA and ESA have made amazing discoveries up to this point," said Ed Weiler,
associate administrator of NASA's Science Mission Directorate in Washington. "Working together,
we'll reduce duplication of effort, expand our capabilities and see results neither ever could have
achieved alone."

NASA and ESA invited scientists worldwide to propose the spacecraft's instruments. The five selected
were from 19 proposals submitted in January. Both agencies evaluated the submissions and chose those
with the best science value and lowest risk.

The selection of the instruments begins the first phase of the new NASA-ESA alliance for future
ventures to Mars. The instruments and the principal investigators are:

-- Mars Atmosphere Trace Molecule Occultation Spectrometer -- A spectrometer designed to detect
very low concentrations of the molecular components of the Martian atmosphere: Paul Wennberg,
California Institute of Technology, Pasadena, Calif.
-- High Resolution Solar Occultation and Nadir Spectrometer -- A spectrometer designed to detect
traces of the components of the Martian atmosphere and to map where they are on the surface: Ann C.
Vandaele, Belgian Institute for Space Aeronomy, Brussels, Belgium.
-- ExoMars Climate Sounder -- An infrared radiometer that provides daily global data on dust, water
vapor and other materials to provide the context for data analysis from the spectrometers: John
Schofield, NASA's Jet Propulsion Laboratory.
-- High Resolution Color Stereo Imager -- A camera that provides four-color stereo imaging at a
resolution of two million pixels over an 8.5 kilometer (5.3 mile) swath: Alfred McEwen, University of
Arizona, Tucson.
-- Mars Atmospheric Global Imaging Experiment -- A wide-angle, multi-spectral camera to provide
global images of Mars in support of the other instruments: Bruce Cantor, Malin Space Science Systems,
San Diego.

The science teams on all the instruments have broad international participation from Europe and the
United States, with important hardware contributions from Canada and Switzerland.

"To fully explore Mars, we want to marshal all the talents we can on Earth," said David Southwood,
ESA director for Science and Robotic Exploration. "Now NASA and ESA are combining forces for
the joint ExoMars Trace Gas Orbiter mission. Mapping methane allows us to investigate further that
most important of questions: Is Mars a living planet, and if not, can or will it become so in the future?"

NASA and ESA share a common interest in conducting robotic missions to the Red Planet for
scientific purposes and to prepare for possible human visits. After a series of extensive discussions, the
science heads of both agencies agreed on a plan of cooperation during a July 2009 meeting in
Plymouth, England, later confirmed by ESA Director General Jean-Jacques Dordain and NASA
Administrator Charles Bolden in a statement of intent that was signed in November 2009.

The plan consists of two Mars cooperative missions in 2016 and 2018, and a later joint sample return
mission. The 2016 mission features the European-built ExoMars Trace Gas Orbiter, a European-built
small lander demonstrator, a primarily-U.S. international science payload, and NASA-provided launch
vehicle and communications components. ESA member states will provide additional instrument
support.

The 2018 mission consists of a European rover with a drilling capability, a NASA rover capable of
caching selected samples for potential future return to Earth, a NASA landing system, and a NASA
launch vehicle. These activities are designed to serve as the foundation of a cooperative program to
increase science returns and move the agencies toward a joint Mars sample return mission in the 2020s.

NASA's Mars Exploration Program seeks to characterize and understand Mars as a dynamic system,
including its present and past environment, climate cycles, geology and potential for life. JPL, a
division of Caltech, manages the program and development of the NASA-supplied instruments for the
2016 orbiter for NASA's Science Mission Directorate in Washington.

For information about NASA's Mars programs, visit http://www.nasa.gov/mars .

-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=krKSJWOAIdLLI8I&s=jjI0J4NJLfJML3OPItG&m=9hLIIUPBKgJQJ9L

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=nuIYK5PMLgKSKiL&s=jjI0J4NJLfJML3OPItG&m=9hLIIUPBKgJQJ9L

NASA's Hibernating Mars Rover May Not Call Home

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

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

NEWS RELEASE: 2010-252 July 30, 2010

NASA'S HIBERNATING MARS ROVER MAY NOT CALL HOME

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-252&cid=release_2010-252

PASADENA, Calif. -- NASA mission controllers have not heard from the Mars Exploration Rover Spirit
since March 22, and the rover is facing its toughest challenge yet – trying to survive the harsh Martian winter.

The rover team anticipated Spirit would go into a low-power "hibernation" mode since the rover was not
able to get to a favorable slope for its fourth Martian winter, which runs from May through November. The
low angle of sunlight during these months limits the power generated from the rover's solar panels. During
hibernation, the rover suspends communications and other activities so available energy can be used to
recharge and heat batteries, and to keep the mission clock running.

On July 26, mission managers began using a paging technique called "sweep and beep" in an effort to
communicate with Spirit.

"Instead of just listening, we send commands to the rover to respond back to us with a communications
beep," said John Callas, project manager for Spirit and its twin, Opportunity, at NASA's Jet Propulsion
Laboratory in Pasadena, Calif. "If the rover is awake and hears us, she will send us that beep."

Based on models of Mars' weather and its effect on available power, mission managers believe that if Spirit
responds, it most likely will be in the next few months. However, there is a very distinct possibility Spirit may
never respond.

"It will be the miracle from Mars if our beloved rover phones home," said Doug McCuistion, director of
NASA's Mars Exploration Program in Washington. "It's never faced this type of severe condition before –
this is unknown territory."

Because most of the rover's heaters were not being powered this winter, Spirit is likely experiencing its
coldest internal temperatures yet -- minus 55 degrees Celsius (minus 67 degrees Fahrenheit). During three
previous Martian winters, Spirit communicated about once or twice a week with Earth and used its heaters
to stay warm while parked on a sun-facing slope for the winter. As a result, the heaters were able to keep
internal temperatures above minus 40 degrees Celsius (which is also minus 40 degrees on the Fahrenheit
scale).

Spirit is designed to wake up from its hibernation and communicate with Earth when its battery charge is
adequate. But if the batteries have lost too much power, Spirit's clock may stop and lose track of time. The
rover could still reawaken, but it would not know the time of day, a situation called a "mission-clock fault."
Spirit would start a new timer to wake up every four hours and listen for a signal from Earth for 20 minutes
of every hour while the sun is up.

The earliest date the rover could generate enough power to send a beep to Earth was calculated to be
around July 23. However, mission managers don't anticipate the batteries will charge adequately until late
September to mid-October. It may be even later if the rover is in a mission-clock fault mode. If Spirit does
wake up, mission managers will do a complete health check on the rover's instruments and electronics.

Based on previous Martian winters, the rover team anticipates the increasing haziness in the sky over Spirit
will offset longer daylight for the next two months. The amount of solar energy available to Spirit then will
increase until the southern Mars summer solstice in March 2011. If we haven't heard from it by March, it is
unlikely that we will ever hear from it.

"This has been a long winter for Spirit, and a long wait for us," said Steve Squyres, the principal investigator
for NASA's two rovers who is based at Cornell University, Ithaca, N.Y. "Even if we never heard from Spirit
again, I think her scientific legacy would be secure. But we're hopeful we will hear from her, and we're eager
to get back to doing science with two rovers again."

Spirit and its twin, Opportunity, began exploring Mars in January 2004 on missions planned to last three
months. Spirit has been nearly stationary since April 2009, while Opportunity is driving toward a large crater
named Endeavour. Opportunity covered more distance in 2009 than in any prior year. Both rovers have
made important discoveries about wet environments on ancient Mars that may have been favorable for
supporting microbial life.

NASA's JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration
Rover project for NASA's Science Mission Directorate in Washington.

For more information about the rovers, visit http://www.nasa.gov/rovers .

- end -

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=jgLPITNALdIJK7J&s=kkL2K7MNLgLOL6PTLuH&m=7qIOL6NELiIOJ4K

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=mtIVI2PMJgKQIhI&s=kkL2K7MNLgLOL6PTLuH&m=7qIOL6NELiIOJ4K

Blowing in the Wind: Cassini Helps with Dune Whodunit

Feature July 29, 2010


Blowing in the Wind: Cassini Helps with Dune Whodunit

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-251&cid=release_2010-251

The answer to the mystery of dune patterns on Saturn's moon Titan did turn out to be
blowing in the wind. It just wasn't from the direction many scientists expected.

Basic principles describing the rotation of planetary atmospheres and data from the
European Space Agency's Huygens probe led to circulation models that showed surface
winds streaming generally east-to-west around Titan's equatorial belt. But when NASA's
Cassini spacecraft obtained the first images of dunes on Titan in 2005, the dunes'
orientation suggested the sands - and therefore the winds - were moving from the
opposite direction, or west to east.

A new paper by Tetsuya Tokano in press with the journal Aeolian Research seeks to
explain the paradox. It explains that seasonal changes appear to reverse wind patterns on
Titan for a short period. These gusts, which occur intermittently for perhaps two years,
sweep west to east and are so strong they do a better job of transporting sand than the
usual east-to-west surface winds. Those east-to-west winds do not appear to gather
enough strength to move significant amounts of sand.

A related perspective article about Tokano's work by Cassini radar scientist Ralph
Lorenz, the lead author on a 2009 paper mapping the dunes, appears in this week's issue
of the journal Science.

"It was hard to believe that there would be permanent west-to-east winds, as suggested
by the dune appearance," said Tokano, of the University of Cologne, Germany. "The
dramatic, monsoon-type wind reversal around equinox turns out to be the key."

The dunes track across the vast sand seas of Titan only in latitudes within 30 degrees of
the equator. They are about a kilometer (half a mile) wide and tens to hundreds of
kilometers (miles) long. They can rise more than 100 meters (300 feet) high. The sands
that make up the dunes appear to be made of organic, hydrocarbon particles. The dunes'
ridges generally run west-to-east, as wind here generally sheds sand along lines parallel to
the equator.

Scientists predicted winds in the low latitudes around Titan's equator would blow east-
to-west because at higher latitudes the average wind blows west-to-east. The wind forces
should balance out, based on basic principles of rotating atmospheres.

Tokano re-analyzed a computer-based global circulation model for Titan he put together
in 2008. That model, like others for Titan, was adapted from ones developed for Earth
and Mars. Tokano added in new data on Titan topography and shape based on Cassini
radar and gravity data. In his new analysis, Tokano also looked more closely at variations
in the wind at different points in time rather than the averages. Equinox periods jumped
out.

Equinoxes occur twice a Titan year, which is about 29 Earth years. During equinox, the
sun shines directly over the equator, and heat from the sun creates upwelling in the
atmosphere. The turbulent mixing causes the winds to reverse and accelerate. On Earth,
this rare kind of wind reversal happens over the Indian Ocean in transitional seasons
between monsoons.

The episodic reverse winds on Titan appear to blow around 1 to 1.8 meters per second (2
to 4 mph). The threshold for sand movement appears to be about 1 meter per second (2
mph), a speed that the typical east-to-west winds never appear to surpass. Dune patterns
sculpted by strong, short episodes of wind can be found on Earth in the northern Namib
sand seas in Namibia, Africa.

"This is a subtle discovery -- only by delving into the statistics of the winds in the model
could this rather distressing paradox be resolved," said Ralph Lorenz, a Cassini radar
scientist based at the Johns Hopkins University Applied Physics Laboratory in Laurel,
Md. "This work is also reassuring for preparations for proposed future missions to Titan,
in that we can become more confident in predicting the winds which can affect the
delivery accuracy of landers, or the drift of balloons."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space
Agency and the Italian Space Agency. JPL manages the Cassini-Huygens mission for
NASA's Science Mission Directorate. The Cassini orbiter was designed, developed and
assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency,
working with team members from the United States and several European countries. JPL
is a division of the California Institute of Technology in Pasadena.

More Cassini information is available, at http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov.

#2010-251

-end-

Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jia-rui.c.cook@jpl.nasa.gov

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=olLYL9MSLjK1LpI&s=ffKSLSPtGbJELRNzHpG&m=6pLML1NBLhJQL8J

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=hoJKIONqFcJOJ5K&s=ffKSLSPtGbJELRNzHpG&m=6pLML1NBLhJQL8J

Curiosity Rover Grows by Leaps and Bounds

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

Curiosity Rover Grows by Leaps and Bounds

Talk about a growth-spurt. In one week, Curiosity grew by approximately 1 meter (3.5
feet) when spacecraft technicians and engineers attached the rover's neck and head
(called the Remote Sensing Mast) to its body. At around 2 meters (about 7 feet) tall, the
next rover to Mars now stands head and shoulders above the rest.

Mounted on Curiosity's mast are two navigation cameras (Navcams), two mast cameras
(Mastcam), and the laser-carrying chemistry camera (ChemCam).

While it now has a good head on its shoulders, Curiosity's "eyes" (the Mastcam), have
been blindfolded in a protective silvery material. The Mastcam, containing two digital
cameras, will soon be unveiled, so engineers can test its picture-taking abilities.

Up next today (July 23), the towering rover will take its first baby steps: a slow roll on the
floor of the clean room where it's being built at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. Watch Curiosity's progress live from the clean room on Ustream until
3:30 p.m. PDT today: http://www.ustream.tv/nasajpl .

Learn more about Curiosity at: http://mars.jpl.nasa.gov/msl/ .

2010-245
-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=muI2KcPLLcKPKgL&s=ddIOKMNlF9KAKLOrHnG&m=7gLNI5PEIhKULbJ

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=fnJOLRMjF5JCIWK&s=ddIOKMNlF9KAKLOrHnG&m=7gLNI5PEIhKULbJ

NASA Spacecraft Camera Yields Most Accurate Mars Map Ever

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.
Jia-rui.c.cook@jpl.nasa.gov

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

Robert Burnham 480-458-8207
Arizona State University, Tempe
Robert.burnham@asu.edu

News release: 2010-244 July 23, 2010

NASA Spacecraft Camera Yields Most Accurate Mars Map Ever

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-244&cid=release_2010-244

PASADENA, Calif. – A camera aboard NASA's Mars Odyssey spacecraft has helped develop the
most accurate global Martian map ever. Researchers and the public can access the map via several
websites and explore and survey the entire surface of the Red Planet.

The map was constructed using nearly 21,000 images from the Thermal Emission Imaging System, or
THEMIS, a multi-band infrared camera on Odyssey. Researchers at Arizona State University's Mars
Space Flight Facility in Tempe, in collaboration with NASA's Jet Propulsion Laboratory in Pasadena,
Calif., have been compiling the map since THEMIS observations began eight years ago.

The pictures have been smoothed, matched, blended and cartographically controlled to make a giant
mosaic. Users can pan around images and zoom into them. At full zoom, the smallest surface details
are 100 meters (330 feet) wide. While portions of Mars have been mapped at higher resolution, this
map provides the most accurate view so far of the entire planet.

The new map is available at: http://www.mars.asu.edu/maps/?layer=thm_dayir_100m_v11 .

Advanced users with large bandwidth, powerful computers and software capable of handling images
in the gigabyte range can download the full-resolution map in sections at:
http://www.mars.asu.edu/data/thm_dir_100m .

"We've tied the images to the cartographic control grid provided by the U.S. Geological Survey,
which also modeled the THEMIS camera's optics," said Philip Christensen, principal investigator for
THEMIS and director of the Mars Space Flight Facility. "This approach lets us remove all instrument
distortion, so features on the ground are correctly located to within a few pixels and provide the best
global map of Mars to date."

Working with THEMIS images from the new map, the public can contribute to Mars exploration by
aligning the images to within a pixel's accuracy at NASA's "Be a Martian" website, which was
developed in cooperation with Microsoft Corp. Users can visit the site at:
http://beamartian.jpl.nasa.gov/maproom#/MapMars .

"The Mars Odyssey THEMIS team has assembled a spectacular product that will be the base map for
Mars researchers for many years to come," said Jeffrey Plaut, Odyssey project scientist at JPL. "The
map lays the framework for global studies of properties such as the mineral composition and physical
nature of the surface materials."

Other sites build upon the base map. At Mars Image Explorer, which includes images from every
Mars orbital mission since the mid-1970s, users can search for images using a map of Mars at:
http://themis.asu.edu/maps .

"The broad purpose underlying all these sites is to make Mars exploration easy and engaging for
everyone," Christensen said. "We are trying to create a user-friendly interface between the public and
NASA's Planetary Data System, which does a terrific job of collecting, validating and archiving
data."

Mars Odyssey was launched in April 2001 and reached the Red Planet in October 2001. Science
operations began in February 2002. The mission is managed by JPL for NASA's Science Mission
Directorate in Washington. Lockheed Martin Space Systems in Denver is the prime contractor for the
project and built the spacecraft. NASA's Planetary Data System, sponsored by the Science Mission
Directorate, archives and distributes scientific data from the agency's planetary missions, astronomical
observations, and laboratory measurements.

For more information about NASA's Odyssey spacecraft, visit: http://mars.jpl.nasa.gov/odyssey .

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

-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=ljJZLePSIhIQKfJ&s=kkK2J7ONJgLOI6MTLuF&m=6fILL2NxFeIQL5K

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=fnKNIWMuHbLFLYI&s=kkK2J7ONJgLOI6MTLuF&m=6fILL2NxFeIQL5K

NASA Telescope Finds Elusive Buckyballs in Space for First Time

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/ Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov / Whitney.Clavin@jpl.nasa.gov

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

NEWS RELEASE: 2010-243 July 22, 2010
NASA TELESCOPE FINDS ELUSIVE BUCKYBALLS IN SPACE FOR FIRST TIME

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-243&cid=release_2010-243

PASADENA, Calif. – Astronomers using NASA's Spitzer Space Telescope have discovered carbon
molecules, known as "buckyballs," in space for the first time. Buckyballs are soccer-ball-shaped
molecules that were first observed in a laboratory 25 years ago.

They are named for their resemblance to architect Buckminster Fuller's geodesic domes, which have
interlocking circles on the surface of a partial sphere. Buckyballs were thought to float around in
space, but had escaped detection until now.

"We found what are now the largest molecules known to exist in space," said astronomer Jan Cami of
the University of Western Ontario, Canada, and the SETI Institute in Mountain View, Calif. "We are
particularly excited because they have unique properties that make them important players for all sorts
of physical and chemical processes going on in space." Cami has authored a paper about the discovery
that will appear online Thursday in the journal Science.

Buckyballs are made of 60 carbon atoms arranged in three-dimensional, spherical structures. Their
alternating patterns of hexagons and pentagons match a typical black-and-white soccer ball. The
research team also found the more elongated relative of buckyballs, known as C70, for the first time
in space. These molecules consist of 70 carbon atoms and are shaped more like an oval rugby ball.
Both types of molecules belong to a class known officially as buckminsterfullerenes, or fullerenes.

The Cami team unexpectedly found the carbon balls in a planetary nebula named Tc 1. Planetary
nebulas are the remains of stars, like the sun, that shed their outer layers of gas and dust as they age.
A compact, hot star, or white dwarf, at the center of the nebula illuminates and heats these clouds of
material that has been shed.

The buckyballs were found in these clouds, perhaps reflecting a short stage in the star's life, when it
sloughs off a puff of material rich in carbon. The astronomers used Spitzer's spectroscopy instrument
to analyze infrared light from the planetary nebula and see the spectral signatures of the buckyballs.
These molecules are approximately room temperature -- the ideal temperature to give off distinct
patterns of infrared light that Spitzer can detect. According to Cami, Spitzer looked at the right place
at the right time. A century from now, the buckyballs might be too cool to be detected.

The data from Spitzer were compared with data from laboratory measurements of the same molecules
and showed a perfect match.

"We did not plan for this discovery," Cami said. "But when we saw these whopping spectral
signatures, we knew immediately that we were looking at one of the most sought-after molecules."

In 1970, Japanese professor Eiji Osawa predicted the existence of buckyballs, but they were not
observed until lab experiments in 1985. Researchers simulated conditions in the atmospheres of aging,
carbon-rich giant stars, in which chains of carbon had been detected. Surprisingly, these experiments
resulted in the formation of large quantities of buckminsterfullerenes. The molecules have since been
found on Earth in candle soot, layers of rock and meteorites.

The study of fullerenes and their relatives has grown into a busy field of research because of the
molecules' unique strength and exceptional chemical and physical properties. Among the potential
applications are armor, drug delivery and superconducting technologies.

Sir Harry Kroto, who shared the 1996 Nobel Prize in chemistry with Bob Curl and Rick Smalley for
the discovery of buckyballs, said, "This most exciting breakthrough provides convincing evidence that
the buckyball has, as I long suspected, existed since time immemorial in the dark recesses of our
galaxy."

Previous searches for buckyballs in space, in particular around carbon-rich stars, proved unsuccessful.
A promising case for their presence in the tenuous clouds between the stars was presented 15 years
ago, using observations at optical wavelengths. That finding is awaiting confirmation from laboratory
data. More recently, another Spitzer team reported evidence for buckyballs in a different type of
object, but the spectral signatures they observed were partly contaminated by other chemical
substances.

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

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

-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=fdKNIQMlHdLOL2I&s=eeJQKPNpFaICJOMvGoG&m=7gKNI3OHJgLHJ4I

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=iqITIZOxFgJVJcL&s=eeJQKPNpFaICJOMvGoG&m=7gKNI3OHJgLHJ4I

NASA Goes Deep in Search of Extreme Environments

Feature July 20, 2010


NASA Goes Deep in Search of Extreme Environments

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-242&cid=release_2010-242

An expedition partially funded by NASA, part of a program to search extreme environments for
geological, biological and chemical clues to the origins and evolution of life, has discovered the
deepest known hydrothermal vent in the world, nearly 5,000 meters (16,400 feet) below the
surface of the western Caribbean Sea. The research will help extend our understanding of the
limits to which life can exist on Earth and help prepare for future efforts to search for life on other
planets.

An interdisciplinary team led by Woods Hole Oceanographic Institution, Woods Hole, Mass., and
including research scientist Max Coleman of NASA's Jet Propulsion Laboratory, Pasadena,
Calif., sailed to the western Caribbean in October 2009 aboard the research vessel Cape
Hatteras. Using sensors mounted on equipment and robotic vehicles, they searched for deep-
sea hydrothermal vents along the 110-kilometer-long (68-mile-long) Mid-Cayman Rise, an ultra-
slow spreading ridge located in the Cayman Trough -- the deepest point in the Caribbean Sea.
Results of their research are published this week in the Proceedings of the National Academy of
Sciences.

While high-temperature submarine vents were first discovered more than 30 years ago, the
majority of the global Mid-Ocean Ridge, an underwater mountain range that snakes its way for
more than 56,000 kilometers (35,000 miles) between Earth's continents, remains unexplored for
hydrothermal activity. While such activity occurs on spreading centers all around the world,
scientists are particularly interested in Earth's ultra-slow spreading ridges, like the Mid-Cayman
Rise, which may host systems that are particularly relevant to pre-biotic chemistry and the
origins of life. The Mid-Cayman Rise is part of the tectonic boundary between the North
American and Caribbean Plates. At the boundary where the plates are being pulled apart, new
material wells up from Earth's interior to form new crust on the seafloor.

The researchers found that the Mid-Cayman Rise hosts at least three discrete hydrothermal
sites, each representing a different type of water-rock interaction. The diversity of the newly
discovered vent types, their geologic settings and their relative geographic isolation make the
Mid-Cayman Rise a unique environment in the world's ocean.

"This was probably the highest-risk expedition I have ever undertaken," said chief scientist Chris
German, a Woods Hole Oceanographic Institution geochemist who has pioneered the use of
autonomous underwater vehicles to search for hydrothermal vent sites. "We know hydrothermal
vents appear along ridges approximately every 100 kilometers [62 miles]. But this ridge crest is
only 100 kilometers long, so we should only have expected to find evidence for one site at most.
So finding evidence for three sites was quite unexpected – but then finding out that our data
indicated that each site represents a different style of venting – one of every kind known, all in
pretty much the same place – was extraordinarily cool."

The team identified the deepest known hydrothermal vent site and two additional distinct types of
vents, one of which is believed to be a shallow, low-temperature vent of a kind that has been
reported only once previously - at the "Lost City" site in the mid-Atlantic Ocean.

"Being the deepest, these hydrothermal vents support communities of organisms that are the
furthest from the ocean surface and sources of energy like sunlight," said JPL co-author
Coleman. "Most life on Earth is sustained by food chains that begin with sunlight as their energy
source. That's not an option for possible life deep in the ocean of Jupiter's icy moon Europa,
prioritized by NASA for future exploration. However, organisms around the deep vents get
energy from the chemicals in hydrothermal fluid, a scenario we think is similar to the seafloor of
Europa, and this work will help us understand what we might find when we search for life there."

"We were particularly excited to find compelling evidence for high-temperature venting at almost
5,000 meters depth," said Julie Huber, a scientist in the Josephine Bay Paul Center at the Marine
Biological Laboratory in Woods Hole. "We have absolutely zero microbial data from high-
temperature vents at this depth." Huber and Marine Biological Laboratory postdoctoral scientist
Julie Smith participated in this cruise to collect samples, and all of the microbiology work for this
paper was carried out in Huber's laboratory. "With the combination of extreme pressure,
temperature and chemistry, we are sure to discover novel microbes in this environment," Huber
added. "We look forward to returning to the Cayman and sampling these vents in the near future.
We are sure to expand the known growth parameters and limits for life on our planet by
exploring these new sites."

For more on this research, read the full news release from Woods Hole Oceanographic Institution:

http://www.whoi.edu/page.do?pid=7545&tid=282&cid=78266&ct=162

#2010-242

-end-

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

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=kiJVK7OLIdLMJcJ&s=llK4KaNRKhLQJ9NXKvE&m=9sLRJ7OELbJUJhI

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=nvL1LgMXLgKTLmI&s=llK4KaNRKhLQJ9NXKvE&m=9sLRJ7OELbJUJhI

NASA's WISE Mission to Complete Extensive Sky Survey

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

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

News release: 2010-238 July 16, 2010

NASA's WISE Mission to Complete Extensive Sky Survey

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-238&cid=release_2010-238

PASADENA, Calif. -- NASA's Wide-field Infrared Survey Explorer, or WISE, will complete its first survey
of the entire sky on July 17, 2010. The mission has generated more than one million images so far, of
everything from asteroids to distant galaxies.

"Like a globe-trotting shutterbug, WISE has completed a world tour with 1.3 million slides covering the
whole sky," said Edward Wright, the principal investigator of the mission at the University of California, Los
Angeles.

Some of these images have been processed and stitched together into a new picture being released today. It
shows the Pleiades cluster of stars, also known as the Seven Sisters, resting in a tangled bed of wispy dust.
The pictured region covers seven square degrees, or an area equivalent to 35 full moons, highlighting the
telescope's ability to take wide shots of vast regions of space.

The new picture was taken in February. It shows infrared light from WISE's four detectors in a range of
wavelengths. This infrared view highlights the region's expansive dust cloud, through which the Seven Sisters
and other stars in the cluster are passing. Infrared light also reveals the smaller and cooler stars of the family.

To view the new image, as well as previously released WISE images, visit http://www.nasa.gov/wise and
http://wise.astro.ucla.edu .

"The WISE all-sky survey is helping us sift through the immense and diverse population of celestial objects,"
said Hashima Hasan, WISE Program scientist at NASA Headquarters in Washington. "It's a great example
of the high impact science that's possible from NASA's Explorer Program."

The first release of WISE data, covering about 80 percent of the sky, will be delivered to the astronomical
community in May of next year. The mission scanned strips of the sky as it orbited around the Earth's poles
since its launch last December. WISE always stays over the Earth's day-night line. As the Earth moves
around the sun, new slices of sky come into the telescope's field of view. It has taken six months, or the
amount of time for Earth to travel halfway around the sun, for the mission to complete one full scan of the
entire sky.

For the next three months, the mission will map half of the sky again. This will enhance the telescope's data,
revealing more hidden asteroids, stars and galaxies. The mapping will give astronomers a look at what's
changed in the sky. The mission will end when the instrument's block of solid hydrogen coolant, needed to
chill its infrared detectors, runs out.

"The eyes of WISE have not blinked since launch," said William Irace, the mission's project manager at
NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Both our telescope and spacecraft have performed
flawlessly and have imaged every corner of our universe, just as we planned."

So far, WISE has observed more than 100,000 asteroids, both known and previously unseen. Most of these
space rocks are in the main belt between Mars and Jupiter. However, some are near-Earth objects,
asteroids and comets with orbits that pass relatively close to Earth. WISE has discovered more than 90 of
these new near-Earth objects. The infrared telescope is also good at spotting comets that orbit far from Earth
and has discovered more than a dozen of these so far.

WISE's infrared vision also gives it a unique ability to pick up the glow of cool stars, called brown dwarfs, in
addition to distant galaxies bursting with light and energy. These galaxies are called ultra-luminous infrared
galaxies. WISE can see the brightest of them.

"WISE is filling in the blanks on the infrared properties of everything in the universe from nearby asteroids to
distant quasars," said Peter Eisenhardt of JPL, project scientist for WISE. "But the most exciting discoveries
may well be objects we haven't yet imagined exist."

JPL manages the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate in
Washington. The mission was selected under NASA's Explorers Program managed by the Goddard Space
Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in
Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., in Boulder, Colo.
Science operations and data processing take place at the Infrared Processing and Analysis Center at the
California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For more information about WISE, visit http://www.nasa.gov/wise and http://wise.astro.ucla.edu .

-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=nvIZIcMZJsI6KrJ&s=jtI0J4OJIfJMI3MPItG&m=buIUIgNWLkJXKlK

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=igLPKXOFKoJOI3K&s=jtI0J4OJIfJMI3MPItG&m=buIUIgNWLkJXKlK

See Beautiful Ontario Lacus: Cassini's Guided Tour

Feature July 15, 2010


See Beautiful Ontario Lacus: Cassini's Guided Tour

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-237&cid=release_2010-237

Ontario Lacus, the largest lake in the southern hemisphere of Saturn's moon Titan, turns
out to be a perfect exotic vacation spot, provided you can handle the frosty, subzero
temperatures and enjoy soaking in liquid hydrocarbon.

Several recent papers by scientists working with NASA's Cassini spacecraft describe
evidence of beaches for sunbathing in Titan's low light, sheltered bays for mooring boats,
and pretty deltas for wading out in the shallows. They also describe seasonal changes in
the lake's size and depth, giving vacationers an opportunity to visit over and over without
seeing the same lake twice. (Travel agents, of course, will have to help you figure out how
to breathe in an atmosphere devoid of oxygen.)

Using data that give us the most detailed picture yet of a lake on another world, scientists
and animators have collaborated on a new video tour of Ontario Lacus (http://www.jpl.nasa.gov/video/index.cfm?id=912.)
based on radar data from Cassini's Titan flybys on June 22, 2009, July 8, 2009, and Jan. 12, 2010.
A Web video explaining how scientists look to Earth's Death Valley are to understand places like
Titan's Ontario Lacus is available at: http://www.jpl.nasa.gov/video/index.cfm?id=913

"With such frigid temperatures and meager sunlight, you wouldn't think Titan has a lot in
common with our own Earth," said Steve Wall, deputy team lead for the Cassini radar
team, based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "But Titan
continues to surprise us with activity and seasonal processes that look marvelously, eerily
familiar."

Cassini arrived at Saturn in 2004 when the southern hemisphere of the planet and its
moons were experiencing summer. The seasons have started to change toward autumn,
with winter solstice darkening the southern hemisphere of Titan in 2017. A year on Titan
is the equivalent of about 29 Earth years.

Titan is the only other world in our solar system known to have standing bodies of liquid
on its surface. Because surface temperatures at the poles average a chilly 90 Kelvin (about
minus 300 degrees Fahrenheit), the liquid is a combination of methane, ethane and
propane, rather than water. Ontario Lacus has a surface area of about 15,000 square
kilometers (6,000 square miles), slightly smaller than its terrestrial namesake Lake Ontario.

Cassini first obtained an image of Ontario Lacus with its imaging camera in 2004. A
paper submitted to the journal Icarus by Alex Hayes, a Cassini radar team associate at the
California Institute of Technology in Pasadena, and colleagues finds that the lake's
shoreline has receded by about 10 kilometers (6 miles). This has resulted in a liquid level
reduction of about 1 meter (3 feet) per year over a four–year period.

The shoreline appears to be receding because of liquid methane evaporating from the lake,
with a total amount of evaporation that would significantly exceed the yearly methane
gas output of all the cows on Earth, Hayes said. Some of the liquid could also seep into
porous ground material. Hayes said the changes in the lake are likely occurring as part of
Titan's seasonal methane cycle, and would be expected to reverse during southern winter.

This seasonal filling and receding is similar to what occurs at the shallow lakebed known
as Racetrack Playa in Death Valley National Park, Hayes said. In fact, from the air, the
topography and shape of Racetrack Playa and Ontario Lacus are quite similar, although
Ontario Lacus is about 60 times larger.

"We are very excited about these results, because we did not expect Cassini to be able to
detect changes of this magnitude in Titan's lakes," Hayes said. "It is only through the
continued monitoring of seasonal variation during Cassini's extended mission that these
discoveries have been made possible."

Other parts of the Ontario Lacus' shoreline, as described in the paper published in
Geophysical Research Letters in March 2010 by Wall, Hayes and other colleagues, show
flooded valleys and coasts, further proof that the lake level has changed.

The delta revealed by Cassini radar data on the western shore of Ontario Lacus is also the
first well-developed delta observed on Titan, Wall said. He explained that the shape of
the land there shows liquid flowing down from a higher plain switching channels on its
way into the lake, forming at least two lobes.

Examples of this kind of channel switching and wave-modified deltas can be found on
Earth at the southern end of Lake Albert between Uganda and the Democratic Republic
of Congo in Africa, and the remains of an ancient lake known as Megachad in the
African country Chad, Wall said.

The radar data also show a smooth beach on the northwestern shore of Ontario Lacus.
Smooth lines parallel to the current shoreline could be formed by low waves over time,
which were likely driven by winds sweeping in from the west or southwest. The pattern
at Ontario Lacus resembles what might be seen on the southeastern side of Lake
Michigan, where waves sculpt the shoreline in a similar fashion.

"Cassini continues to take our breath away as it fills in the details on the surfaces of these
far-off moons," said Linda Spilker, Cassini project scientist based at JPL. "It's
exhilarating to ride along as it takes us on the ultimate cold-weather adventure."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space
Agency and the Italian Space Agency. JPL manages the Cassini-Huygens mission for
NASA's Science Mission Directorate. The Cassini orbiter was designed, developed and
assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency,
working with team members from the United States and several European countries.

More Cassini information is available, at http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov.

#2010-237

-- end --

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=mkIXJ5PMKmL3InI&s=fpKSISNtFbIEJROzEpE&m=cvJWIiPYLiJWJnJ

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=fdJJKKNkEfKQK3L&s=fpKSISNtFbIEJROzEpE&m=cvJWIiPYLiJWJnJ