A clearer view of Titan.

Peering through the hydrocarbon haze that shrouds Saturn's moon Titan, astronomers have obtained the sharpest images ever taken of the surface of this mysterious body. Infrared pictures reveal a complex terrain of bright regions that could be continents of ice and rock, as well as dark areas that could be oceans of hydrocarbons.

Researchers have long been interested in Titan because of its chemistry. They suspect that some of the organic compounds in its atmosphere could have rained onto its moon's surface and created a complex mixture similar to that on Earth's surface before life emerged (SN: 11/1/97, p. 284).

To observe Titan, Claire E. Max of the Lawrence Livermore (Calif.) National Laboratory and her colleagues used the giant Keck I Telescope atop Hawaii's Mauna Kea. The team viewed the surface in the infrared, since this radiation passes through Titan's hydrocarbon smog.

To overcome image blurring due to Earth's rapidly changing atmosphere, the astronomers took extremely fast snapshots. By combining hundreds of these images, they created a map of Titan's surface that is sharper than that taken by the Hubble Space Telescope (SN: 11/12/94, p. 309), Max says. She and her colleagues describe their results in the July ICARUS.

The high-precision images "are better than the Hubble images," says Jonathan I. Lunine of the University of Arizona in Tucson. Some of the very dark areas in the new Titan map "could indeed contain liquid," he adds. If so, it would be the first open sea discovered beyond Earth.

Images of Titan may soon become even sharper, notes Lunine. Livermore researchers are testing an automated system that will allow Keck's mirror to compensate directly for the distortions generated by Earth's atmosphere. Furthermore, a probe on the Saturn-bound Cassini spacecraft is scheduled to parachute onto Titan in 2004. That mission could settle the question of whether this moon has a dark sea.