Titan is the only moon in the solar system with a thick atmosphere. Composed primarily of nitrogen and methane, it is so thick that astronomers have been unable, until recently, to see anything below its very uppermost layers. But recent observations using the Keck Telescope in Hawaii, and the Hubble Space Telescope have revealed some surface and atmospheric features of the solar system's most mysterious moon.

These images may help scientists plan and target the descent of the Huygens probe, a Cassini-project scientist told space.com Thursday. Martin Tomasko, a planetary scientist at the University of Arizona's Lunar and Planetary Laboratory, said images of cloud movement could help scientists determine wind speed and direction in the hazy mix of gasses. That would allow them to better anticipate just how much the probe will be moved around as it falls to Titan's surface in late 2004.

The Huygens probe is the European Space Agency's contribution to the Cassini mission. It is traveling with Cassini and will parachute through Titan's atmosphere, taking a host of measurements as it drops. Scientists hope it will function until it lands on the surface, and possibly even afterwards, depending on what it hits.

Little is known of the Titan's surface, but the recent Keck and Hubble images are providing clues. It could be composed hard rock and have hydrocarbon seas, or large areas covered with ethane or methane ice and snow.

Tomasko, who is principal investigator for the imaging camera that will serve as Huygens' eyes, hopes to use the camera to find out for certain. Until then, Tomasko said he hopes that better observations from Keck and Hubble will provide information that could help Huygens scientists avoid the most treacherous surface obstacles, such as jagged mountains or seas.

If Huygens lands on a forgiving surface, it could continue to send back data after landing. During tests of the instrument in northern Europe, an engineering model of the probe survived snowbank landings.

Still, the probe will be at the mercy of Titan's winds, which scientists know almost nothing about. Tomasko said future observations of clouds could change that, and allow engineers to predict how much drifting, swinging and swaying the parachuting probe will do.