September 17th 05, 01:31 AM
http://www.jpl.nasa.gov/news/news.cfm?release=2005-151
Carolina Martinez (818) 354-9382
Jet Propulsion Laboratory, Pasadena, Calif.
2005-151
Cassini Radar Images Show Dramatic Shoreline on Titan
September 16, 2005
Images returned during Cassini's recent flyby of Titan show captivating
evidence of what appears to be a large shoreline cutting across the
smoggy moon's southern hemisphere. Hints that this area was once wet,
or
currently has liquid present, are evident.
"We've been looking for evidence of oceans or seas on Titan for some
time. This radar data is among the most telling evidence so far for a
shoreline," said Steve Wall, radar deputy team leader from NASA's Jet
Propulsion Laboratory, Pasadena, Calif.
The new radar images can be seen at: http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov .
The images show what looks like a shoreline dividing a distinct bright
and dark region roughly 1,700 kilometers long by 170 kilometers wide
(1,060 by 106 miles). Directly to the right of a bright and possibly
rough area is one that is very dark and smooth.
"This is the area where liquid or a wet surface has most likely been
present, now or in the recent past, said Wall. "Titan probably has
episodic periods of rainfall or massive seepages of liquid from the
ground."
The brightness patterns in the dark area indicate that it may once have
been flooded with liquid that may now have partially receded. Bay-like
features also lead scientists to speculate that the bright-dark
boundary
is most likely a shoreline.
"We also see a network of channels that run across the bright terrain,
indicating that fluids, probably liquid hydrocarbons, have flowed
across
this region," said Dr. Ellen Stofan, Cassini associate radar team
member
from Proxemy Research, Laytonsville, Md.
Taken together with the two other radar passes in October 2004 and
February 2005, these very high resolution images have identified at
least two distinct types of drainage and channel formation on Titan.
Some channels in images from this pass are long and deep, with angular
patterns and few tributaries, suggesting that fluids flow over great
distances. By contrast, others show channels that form a denser network
that might indicate rainfall.
Dr. Larry Soderblom with the U.S. Geological Survey in Flagstaff,
Ariz.,
said, "It looks as though fluid flowed in these channels, cutting
deeply
into the icy crust of Titan. Some of the channels extend over 100
kilometers (60 miles). Some of them may have been fed by springs, while
others are more complicated networks that were likely filled by
rainfall."
Titan has an environment somewhat similar to that of Earth before
biological activity forever altered the composition of Earth's
atmosphere. The major difference on Titan, however, is the absence of
liquid water, and Titan's very low temperature. With a thick,
nitrogen-rich atmosphere, Titan was until recently presumed to hold
large seas or oceans of liquid methane. Cassini has been in orbit
around
Saturn for a year and has found no evidence for these large seas.
Cassini encountered an anomaly with one of two solid-state recorders
during the Sept. 7 close flyby, resulting in some data not being
recorded. Half of the data from the flyby was received, much to the
delight of anxious scientists. The spacecraft team is troubleshooting
the cause, and early indications point to a software problem that would
be correctable with no long-term impacts.
This was Cassini's eighth out of 45 Titan flybys planned in the nominal
four-year tour. The next radar pass will be Oct. 26 when the team will
focus on the Huygens probe landing site close to the equator.
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. The radar instrument team is based at JPL, working with team
members from the United States and several European countries.
Carolina Martinez (818) 354-9382
Jet Propulsion Laboratory, Pasadena, Calif.
2005-151
Cassini Radar Images Show Dramatic Shoreline on Titan
September 16, 2005
Images returned during Cassini's recent flyby of Titan show captivating
evidence of what appears to be a large shoreline cutting across the
smoggy moon's southern hemisphere. Hints that this area was once wet,
or
currently has liquid present, are evident.
"We've been looking for evidence of oceans or seas on Titan for some
time. This radar data is among the most telling evidence so far for a
shoreline," said Steve Wall, radar deputy team leader from NASA's Jet
Propulsion Laboratory, Pasadena, Calif.
The new radar images can be seen at: http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov .
The images show what looks like a shoreline dividing a distinct bright
and dark region roughly 1,700 kilometers long by 170 kilometers wide
(1,060 by 106 miles). Directly to the right of a bright and possibly
rough area is one that is very dark and smooth.
"This is the area where liquid or a wet surface has most likely been
present, now or in the recent past, said Wall. "Titan probably has
episodic periods of rainfall or massive seepages of liquid from the
ground."
The brightness patterns in the dark area indicate that it may once have
been flooded with liquid that may now have partially receded. Bay-like
features also lead scientists to speculate that the bright-dark
boundary
is most likely a shoreline.
"We also see a network of channels that run across the bright terrain,
indicating that fluids, probably liquid hydrocarbons, have flowed
across
this region," said Dr. Ellen Stofan, Cassini associate radar team
member
from Proxemy Research, Laytonsville, Md.
Taken together with the two other radar passes in October 2004 and
February 2005, these very high resolution images have identified at
least two distinct types of drainage and channel formation on Titan.
Some channels in images from this pass are long and deep, with angular
patterns and few tributaries, suggesting that fluids flow over great
distances. By contrast, others show channels that form a denser network
that might indicate rainfall.
Dr. Larry Soderblom with the U.S. Geological Survey in Flagstaff,
Ariz.,
said, "It looks as though fluid flowed in these channels, cutting
deeply
into the icy crust of Titan. Some of the channels extend over 100
kilometers (60 miles). Some of them may have been fed by springs, while
others are more complicated networks that were likely filled by
rainfall."
Titan has an environment somewhat similar to that of Earth before
biological activity forever altered the composition of Earth's
atmosphere. The major difference on Titan, however, is the absence of
liquid water, and Titan's very low temperature. With a thick,
nitrogen-rich atmosphere, Titan was until recently presumed to hold
large seas or oceans of liquid methane. Cassini has been in orbit
around
Saturn for a year and has found no evidence for these large seas.
Cassini encountered an anomaly with one of two solid-state recorders
during the Sept. 7 close flyby, resulting in some data not being
recorded. Half of the data from the flyby was received, much to the
delight of anxious scientists. The spacecraft team is troubleshooting
the cause, and early indications point to a software problem that would
be correctable with no long-term impacts.
This was Cassini's eighth out of 45 Titan flybys planned in the nominal
four-year tour. The next radar pass will be Oct. 26 when the team will
focus on the Huygens probe landing site close to the equator.
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. The radar instrument team is based at JPL, working with team
members from the United States and several European countries.