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Carolina Martinez 818-354-9382
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown 202-358-1726
NASA Headquarters, Washington
News Release: 2007-026 March 13, 2007
Cassini Spacecraft Images Seas on Saturn's Moon Titan
Instruments on NASA's Cassini spacecraft have found evidence for seas, likely filled
with liquid methane or ethane, in the high northern latitudes of Saturn's moon Titan. One
such feature is larger than any of the Great Lakes of North America and is about the same
size as several seas on Earth.
Cassini's radar instrument imaged several very dark features near Titan's north pole.
Much larger than similar features seen before on Titan, the largest dark feature measures
at least 100,000 square kilometers (39,000 square miles). Since the radar has caught only
a portion of each of these features, only their minimum size is known. Titan is the second
largest moon in the solar system and is about 50 percent larger than Earth's moon.
"We've long hypothesized about oceans on Titan and now with multiple instruments we
have a first indication of seas that dwarf the lakes seen previously," said Dr. Jonathan
Lunine, Cassini interdisciplinary scientist at the University of Arizona, Tucson.
While there is no definitive proof yet that these seas contain liquid, their shape, their dark
appearance in radar that indicates smoothness, and their other properties point to the
presence of liquids. The liquids are probably a combination of methane and ethane, given
the conditions on Titan and the abundance of methane and ethane gases and clouds in
Titan's atmosphere.
Cassini's visual and infrared mapping spectrometer also captured a view of the region,
and the team is working to determine the composition of the material contained within
these features to test the hypothesis that they are liquid-filled.
The imaging cameras, which provide a global view of Titan, have imaged a much larger,
irregular dark feature. The northern end of their image corresponds to one of the radar-
imaged seas. The dark area stretches for more than 1,000 kilometers (620 miles) in the
image, down to 55 degrees north latitude. If the entire dark area is liquid-filled, it would
be only slightly smaller than Earth's Caspian Sea. The radar data show details at the
northern end of the dark feature similar to those seen in earlier radar observations of
much smaller, liquid-filled lakes. However, to determine if the entire dark feature is a
liquid-filled basin will require investigation through additional radar flyovers later in the
mission.
The presence of these seas reinforces current thinking that Titan's surface must be re-
supplying methane to its atmosphere, the original motivation almost a quarter century ago
for the theoretical speculation of a global ocean on Titan.
Cassini's instruments are peeling back the haze that shrouds Titan, showing high northern
latitudes dotted with seas hundreds of miles across, and hundreds of smaller lakes that
vary from several to tens of miles.
Due to the new discoveries, team members are re-pointing Cassini's radar instrument
during a May flyby so it can pass directly over the dark areas imaged by the cameras.
For images and more information visit: http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov .
The Cassini-Huygens mission is a cooperative project of NASA, the European Space
Agency and the Italian Space Agency. JPL, a division of the California Institute of
Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science
Mission Directorate, Washington. The Cassini orbiter was designed, developed and
assembled at JPL.
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