U of I helps explore strange new worlds
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October 24, 2013 |
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| The
bus-sized Cassini spacecraft releases
the European Space Agency’s Huygens
probe over hazy Titan. Image: NASA. |
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A team of NASA researchers around the nation,
including scientists at the University of Idaho,
revealed today a new view of Saturn’s moon
Titan.
With the sun now shining down over Titan, a
little luck with the weather, and trajectories
that put the spacecraft into optimal viewing
positions, NASA's Cassini spacecraft has
obtained new pictures of the liquid methane and
ethane seas and lakes that reside near Titan's
north pole. The images reveal new clues about
how the lakes formed and Titan's Earth-like
"hydrologic" cycle that involves hydrocarbons
rather than water.
"The view from Cassini's visual and infrared
mapping spectrometer gives us a holistic view of
an area that we'd only seen in bits and pieces
before and at a lower resolution," said Jason
Barnes, an associate professor in the UI
Department of Physics who is part of NASA’s
Cassini visual and Infrared mapping
spectrometer, or VIMS, team. "It turns out that
Titan's north pole is even more interesting than
we thought, with a complex interplay of liquids
in lakes and seas and deposits left from the
evaporation of past lakes and seas."
Both Barnes and Matt Hedman, an assistant
professor of physics at UI, work on the Cassini
project as participating scientists in the VIMS
team, which has recently released a number of
images including a spectacular view of Saturn
and its rings backlit by the sun.
Three doctoral students working under Barnes –
Graham Vixie, Casey Cook, and Shannon MacKenzie
– also work on the project, as well as
undergraduate student Corbin Hennen.
While there is one large lake and a few smaller
ones near Titan's south pole, almost all of
Titan's lakes appear near the moon's north pole.
Cassini scientists have been able to study much
of the terrain with radar, which can penetrate
beneath Titan's clouds and thick haze. And
Cassini's VIMS and imaging science subsystem
have only been able to capture distant, oblique
or partial views of this area until now.
Several factors combined recently to give these
instruments great observing opportunities. Two
recent flybys provided better viewing geometry.
Sunlight has begun to pierce the winter darkness
that shrouded Titan's north pole at Cassini's
arrival in the Saturn system nine years ago. A
thick cap of haze that once hung over the north
pole has also dissipated as northern summer
approaches. And, thankfully, Titan's beautiful,
almost cloudless, rain-free weather continued
during Cassini's flybys this past summer.
The image from VIMS is a mosaic in infrared
light based on data obtained during a flyby of
Titan on Sept. 12, 2013. The colorized mosaic,
which maps infrared colors onto the
visible-color spectrum, reveals differences in
the composition in material around the lakes.
The data suggest parts of Titan's lakes and seas
may have evaporated and left behind the Titan
equivalent of Earth's salt flats. Only here, the
evaporated material is thought to be organic
chemicals originally from Titan's haze particles
that once dissolved in liquid methane. They
appear orange in this image against the greenish
backdrop of Titan's typical bedrock of water
ice.
Launched in 1997, Cassini has been exploring the
Saturn system since 2004. A full Saturn year is
30 years and Cassini has been able to observe
nearly a third of a Saturn year. In that time,
Saturn and its moons have seen the seasons
change from northern winter to northern summer.
"Titan's northern lakes region is one of the
most Earth-like and intriguing in the solar
system," said Linda Spilker, the Cassini project
scientist based at NASA's Jet Propulsion
Laboratory in Pasadena, Calif. "We know lakes
here change with the seasons and Cassini's long
mission at Saturn gives us the opportunity to
watch the seasons change at Titan, too. Now that
the sun is shining in the north and we have
these wonderful views, we can begin to compare
the different data sets and tease out what
Titan's lakes are doing near the north pole."
The Cassini-Huygens mission is a cooperative
project of NASA, the European Space Agency and
the Italian Space Agency. JPL manages the
mission for NASA's Science Mission Directorate,
Washington. The California Institute of
Technology in Pasadena manages JPL for NASA. The
VIMS team is based at the University of Arizona
in Tucson. The imaging operations center is
based at the Space Science Institute in Boulder,
Colorado.
For more information about the Cassini mission,
visit:
www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov. |
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