LHC@home

from Jet Propulsion Laboratory, Pasadena, Calif.USA
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Early analysis of images and other data captured during last
night's close flyby of Saturn's moon Titan by the Cassini
spacecraft reveals greater surface detail than ever before
and shows that Titan has lost much of its original
atmosphere over time.

"Titan has incredible diversity," said Dr. Dennis Matson,
project scientist for the Cassini-Huygens mission at NASA's
Jet Propulsion Laboratory, Pasadena, Calif. "We are glad
that we have a full complement of instruments on this
spacecraft because it is going to take all of them to reveal
the story of Titan."

Pictures from the imaging cameras and the visual and
infrared mapping spectrometer show a complex interplay
between dark and bright material on Titan's surface. The
surface appears to have been shaped by multiple geologic
processes. Although a few circular features can be seen,
none can be definitively identified as impact craters.

"We are seeing features and patterns on the surface, and
there are processes creating these patterns, and that gives
us something to chew on for a while," said Dr. Carolyn
Porco, team leader for the imaging team, Space Science
Institute, Boulder, Colo. "We can't figure out what the
features are, but they are intriguing. This is an
environment we have never seen before. It is a very
different place and it will take some time to unravel and
piece it all together."

Cassini scientists were intrigued that the spacecraft's ion
and neutral mass spectrometer found that Titan's atmosphere
has more of the heavy isotope of nitrogen, compared to the
lighter form. They believe that when nitrogen molecules
rose to the top of the atmosphere, the lighter form was
swept away with greater efficiency than the heavier form.


Eleven of Cassini's 12 instruments were on during the flyby.
Ten instruments returned data successfully. Engineers are
working on a software glitch that caused the composite
infrared spectrometer to malfunction. The team is confident
that subsequent flybys of Titan will allow them to collect
any data not gathered last night.

Cassini swooped down to within 1,174 kilometers (730 miles)
of Titan during the close encounter. During the flyby,
ground controllers were not in contact with the spacecraft,
because it was turned away from Earth to make its
observations. The signal was re-acquired as expected at
9:25 p.m. Eastern Daylight Time yesterday (6:25 p.m. Pacific
Daylight Time).

Titan holds great fascination because it is the only known
moon in the solar system to have an atmosphere. That murky
atmosphere may be similar to that which existed on Earth
before life formed. Cassini will become a frequent visitor
to Titan, with 44 more targeted flybys planned during the
mission. In addition, its piggybacked Huygens probe, built
and managed by the European Space Agency, will be released
on Christmas Eve for a descent into Titan's atmosphere.

"A major goal of this flyby was to measure the properties of
Titan's atmosphere to see if our models to simulate the
Huygens entry and descent are accurate, and to assess the
feasibility of subsequent flybys at the 950 kilometer
altitude [590 miles]," said Dr. Earl Maize, Cassini deputy
program manager at JPL. "Preliminary data from last night's
flyby are consistent with current predictions."