The Cassini spacecraft orbiting Saturn has found a mile-high mountain range on the giant moon Titan, scientists said Tuesday.
The range, in the moon's southern hemisphere, is nearly 100 miles long. It is the tallest range on Titan found by Cassini, which has been investigating the Saturnian satellite for the last two years.
Cassini scientists have dubbed the mountains Titan's Sierra Nevada.
"These mountains are probably hard as rock, made of icy materials, and are coated with different layers of organics," said Larry Soderblom, a Cassini scientist at the U.S. Geological Survey in Flagstaff, Ariz.
The latest Titan discoveries, released Tuesday at the annual meeting of the American Geophysical Union meeting in San Francisco, came from a close fly-by of the moon on Oct. 25.
The Cassini-Huygens mission, a cooperative project of the Jet Propulsion Laboratory in La Canada Flintridge and the European and Italian space agencies, has shown Titan to be one of the more unusual bodies in the solar system.
It rains methane, has lakes of gasoline-like liquids and experiences occasional eruptions into the frigid atmosphere of cryogenic magma, a pasty concoction of frozen debris.
Layers of organic material -- referred to as "gunk" by the scientists and made of ice, dust, rain and smog-like substances -- coat the mountaintops, the scientists said at a media briefing.
Besides the mountain range, the latest images revealed dunes and deposits that resembled volcanic flows.
Scientists also are studying a persistent band of clouds in Titan's midsouthern latitudes. They now think the clouds are methane droplets that form when the atmosphere is pushed over the mountains by winds, cooling it and causing condensation.
The scientists also believe they understand Titan's ubiquitous dunes much better, they said. "The dunes seem to consist of sand grains made of organics, built on water-ice bedrock, and there may also be some snow," said Robert H. Brown, a researcher at the University of Arizona.
Some scientists believe that with the plentiful supply of organic compounds, Titan might support some form of life, and they are pushing for another mission to the moon.
But with space science advocates lobbying for missions to Jupiter's moon Europa and another intriguing moon of Saturn, Enceladus, where a water geyser was recently spotted, it could be decades before a follow-up mission is launched, Brown said.
Cassini's mission is expected to last two more years. So far, radar has mapped 10% of the surface.