Cassini Scientists Rethinking Titan
NASA and the European Space Agency became fascinated with
Saturn's moon, Titan, after analyzing the data from Voyager's flyby
in 1980 and 1981. That's when they discovered the moon's dense
atmosphere, made mostly of methane. Why, they wondered, at
temperatures prevalent on Titan, doesn't the methane fall from the
sky like rain? Perhaps there was a ocean of methane on the
So they decided to launch Cassini-Huygens at a cost of $3.27
billion. But instead of answers, researchers are finding fuel for
more and more questions.
Even though the Titan telemetry from Cassini isn't quite what
scientists were hoping for, they're seeing lines that could
indicate cracks in the ice covering the surface. That could be a
sign that Titan is all shook up by quakes -- meaning the Saturnian
moon is a lot more geologically active than first believed.
Dark-hued plateaus once thought to be covered in a sort of
carbon-based tar appear instead to be covered with ice.
Light-colored plateaus once thought to be made up of ice or
liquid methane are instead a mixture of water and carbon-tar.
In spots where the plateaus butt up against each other, lines
that should appear sharp -- as they do on Ganymede -- are instead
fuzzy. Ellis Miner at the Jet Propulsion Lab in Pasadena (CA) tells
USA Today, "I think the fuzziness we've seen so far is telling us
something is going on down there."
There are very few craters pockmarking Titan's surface. That
leads scientists to theorize that impacts are quickly covered up by
wind or perhaps even some sort of icy volcanos.
"I think there's more surprise than disappointment," Miner tells
USA Today. "We're going to see some really fascinating things."
Elizabeth Tuttle, a University of Arizona scientist on the
Cassini imaging team, agrees. "The story has changed completely,"
she told the national newspaper.
Tuttle, Miner and other scientists expect more answers in
January. That's when Cassini will pass within 746 miles of Titan
and release a drop-ship, the Huygens lander. Combined data from
both vehicles is expected to clear up a lot of things about
Saturn's most fascinating moon -- but, as with the mission so far,
it could also raise more questions.