Oct. 27, 2004 — The Cassini spacecraft on Tuesday had a successful close encounter with Saturn's cloud-shrouded moon Titan, a world bigger than Mercury that scientists believe harbors an atmospheric brew resembling early Earth.

Cassini operators at the Jet Propulsion Laboratory in Pasadena, Calif., began receiving their first data from the probe Tuesday night after the spacecraft passed as close as 745 miles, or 1,200 kilometers, from the moon's surface.

As Cassini skimmed just beyond the top of the Titan's thick atmosphere, its instruments not only captured the first images of the world, but also collected information about the moon's physical and chemical composition.

"Titan is the largest piece of unexplored territory in the solar system," said Cassini scientist Ralph Lorenz with the University of Arizona.

Titan is among the prime targets for Cassini's four-year study of Saturn. It is the only moon in the solar system that has a thick atmosphere. An ocean of liquid methane and ethane may lurk beneath the moon's thick haze, chemicals that were prevalent in primordial Earth.

Scientists doubt life could have developed on Titan, where temperatures are believed to reach about minus 290 degrees Fahrenheit.

During the flyby — the first of 45 planned for Cassini — scientists were hoping to use the spacecraft's radar to pierce the thick atmosphere and image the moon's surface.

Getting a fix on the land and seas is important for the upcoming release of a probe that will descend through Titan's atmosphere and land. The European Space Agency's Huygen's spacecraft will be released from Cassini on Dec. 24 for an independent mission to Titan.

As it descends, the probe will sample the atmosphere and relay the findings to its mothership for return to Earth.

"Cassini may finally show us if what we thought of this moon is true, and whether the Huygens probe touchdown will be a splash," said Jean-Pierre Lebreton, Huygens project manager.

"We know our instrument will see through the haze to Titan's surface," added University of Arizona's Robert Brown, team leader for the visual and infrared mapping spectrometer. "This encounter is about digging down below the atmosphere and getting our first glimpse of Titan geology."