 | Titan found to offer Earth-like qualities
By Elizabeth Bryant
UNITED PRESS INTERNATIONAL
Paris, France, Jan. 21 (UPI) -- A week after the European Space
Agency's Huygens probe landed on the spongy surface of Saturn's largest
and most mysterious moon, European and American scientists said Friday
they are learning startling new information about Titan.
Colored pinky orange and etched with spidery fissures, the remote moon
appears to share many of the gaseous elements and physical
characteristics of planet Earth.
River and stream beds seem to crisscross the surface of Titan,
currently located about 800 million miles from Earth. Chunks of
rocklike substances scatter the images sent by Huygens over several
hours before NASA's Cassini spacecraft -- which carried the probe to
Titan -- passed behind the moon and out of radio range.
"Our new picture of Titan is really fascinating," said Jean-Pierre
Lebreton, mission manager for Huygens at the European Space Agency,
during a news conference in Paris. "What we are seeing is Earth-like
processes on Titan, but the big difference is the ingredients are
somewhat different."
The space probe plunged through the murky, chilling air of Titan one
week ago, landing on a surface scientists described as wet sand or soft
clay. Pictures sent by Huygens showed a flat terrain dotted with sand
and fist-sized chunky objects. Scientists think the sand actually is
composed of icy shards, and the chunks large pieces of ice.
"We see evidence of what might be called dirt," said Martin Tomasko, a
scientist at the University of Arizona in Tucson, and one of the
principal investigators for NASA of the Titan mission. "There's dark
material, almost certainly there's organic material in the smog that
has fallout out and settled on the ground."
The liquid flowing on Titan's surface -- including what scientists
think may be rain -- is methane, not water. Indeed, on Earth methane
would exist as a highly combustible gas, but Titan's frigid atmosphere
lacks oxygen -- otherwise the moon would have exploded a long time ago.
The Titan landing was a joint project between the ESA, NASA and the
Italian Space Agency, but the stunning images amount to a particular
coup for the 15-member ESA team, which for years has labored in the
shadow of its more established U.S. and Russian counterparts.
The Europeans also are savoring the earlier success of their Mars
Express Orbiter mission, which produced photographs its scientists said
offer the most direct evidence that water, in ice form, exists on the
red planet.
Other future projects include two more missions to Mars and one to
Venus. At the news conference Friday, the scientists also suggested it
might be possible to explore Titan in the future with a moving rover.
The message, said David Southwood, the ESA's director of science
programs, is "we're in the exploration business now."
The Titan scientists said it will take weeks and months to sift through
the rich trove of data sent by Huygens during the two hours or so it
parachuted down through the giant moon's atmosphere -- Titan is larger
than the planets Mercury and Pluto -- to its surface, where it
eventually settled on dry land.
"It's more like Arizona or a place like that, where river beds are dry
most of the time," Tomasko said.
One of the many remaining mysteries is whether the Huygens landing site
is representative of the entire moon, or whether there are more humid
areas as well. The scientists said they are uncertain whether Titan has
seasons, but they think there is regular precipitation on Titan -- it
could very well have rained liquid methane the day before the probe
landed.
Even with its physical resemblance to Earth, it would be extremely
difficult for Earth-like life to have developed on this frozen, far-off
moon. Still, there will come a time -- at least several billion years
from now -- when the sun expands and swallows the Earth. Then,
temperatures will rise on Titan and other far-off corners of the solar
system.
"Because we have the very basic building blocks for life, in the form
of organic molecules, for a very brief time Titan may be a very good
place for life," said Toby Owen, a researcher at the University of
Hawaii.
For the moment, however, it appears humans are better off exploring
Titan using robotic craft such as Huygens, perhaps followed in the
coming decades by updated versions of NASA's Mars Exploration Rovers.
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E-mail sciencemail@upi.com
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