A strikingly bright, lobate feature has turned up in one of Cassini’s first
radar images of Saturn’s moon Titan.

“It may be something that flowed,” Cassini radar team member Ralph Lorenz
of the University of Arizona said. “Or it could be something carved by
erosion. It’s too early to say.

“But it looks very much like it’s something that oozed across the surface.
It may be some sort of ‘cryovolcanic’ flow, an analog to volcanism on Earth
that is not molten rock but, at Titan’s very cold temperatures, molten ice.”

The radar image is online at http://saturn.jpl.nasa.gov and
http://www.nasa.gov/cassini .

Cassini radar mapped about one percent of Titan’s surface during the
Cassini spacecraft’s first close Titan flyby Oct. 26. The radar survey
covered a strip 75 miles wide (120 kilometers) and 1,200 miles (1,960
kilometers) long in Titan’s northern hemisphere.

Cassini was flying about 1,550 miles (2,494 kilometers) above Titan’s
surface, with its radar centered at about 45 degrees north, 30 degrees
west, when it mapped the 90-square-mile (230-square-kilometer) area shown
in the new radar image.

The Cassini radar team presented the image today at the 86th annual meeting
of the American Astronomical Society Division of Planetary Sciences in
Louisville, Ky.

The radar instrument works by bouncing radio signals off Titan’s surface
and timing their return. The more signal reflected back to the
spacecraft, the brighter the imaged area. Turning radio signals into
radar images is time consuming because so many numerical calculations must
be made. “There’s no such thing as a ‘raw’ radar image,” Lorenz said.
But two days after the Oct. 26 flyby, Cassini scientists knew that Titan is
no impact-crater-pocked dead world, but a much more interesting place.
Titan’s surface is young — it’s been shaped by dynamic geologic
processing, Lorenz, Cassini interdisciplinary scientist Jonathan Lunine of
the University of Arizona, and other Cassini scientists agree.

Given this newest image, Lunine said, “Radar has provided the first
evidence for possible young cryovolcanism on Titan’s surface. Now our
challenge is to find out what is flowing, how it works, and the
implications for Titan’s evolution.”

The Cassini-Huygens 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
Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington,
D.C. The Cassini orbiter and its two onboard cameras were designed,
developed and assembled at JPL. The radar instrument team is based at JPL,
working with team members from the United States and several European
countries.

PHOTO CAPTION: Oozing across Titan

This synthetic aperture radar image of the surface of Saturn¹s moon Titan
was acquired on October 26, 2004, when the Cassini spacecraft flew
approximately 2,500 kilometers above the surface and acquired radar data
for the first time.

The radar illumination was from the south. Dark regions may represent areas
that are smooth, made of radar-absorbing materials, or are sloped away from
the direction of illumination. A striking lobate bright feature stretches
from upper left to lower right across this image, with connected Œarms¹ to
the east. The fact that the lower (southern) edges of the features are
brighter is consistent with the lobate structure being raised above the
relatively featureless darker background. Comparisons with other features
and data from other instruments will help to determine whether this is a
cryovolcanic flow, where water-rich liquid has welled up from Titan¹s warm
interior.

The image is about 150 kilometers (90 miles) square, and is centered at
about 45 N, 30 W in the northern hemisphere of Titan, over a region that
has not yet been imaged optically. The smallest details seen on the image
are around 1 kilometer (.62 mile) across. Features are less clear at the
bottom of the image where the viewing was less favorable. A faint
horizontal seam between the radar beams can be seen half way up in this
preliminary product.

The Cassini-Huygens 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
Cassini-Huygens mission for NASA¹s Science Mission Directorate, Washington,
D.C. The Cassini orbiter and its two onboard cameras were designed,
developed and assembled at JPL. The RADAR instrument team is based at
NASA¹s Jet Propulsion Laboratory, Pasadena, Calif., working with team
members from the USA and several European countries. (Image credit:
NASA/JPL)

For the latest news about the Cassini-Huygens mission visit
http://www.nasa.gov/cassini. For more information about the mission visit
http://saturn.jpl.nasa.gov.