Is Saturn satellite a source for unknown space alien life forms?

San Francisco Chronicle

SAN FRANCISCO — Volcanoes on a distant moon of the planet Saturn are erupting and spewing a gassy slurry of icy ammonia, water and methane into Titan’s thick red, tarlike atmosphere, NASA scientists are reporting this week.

The frozen mixture of those chemicals and heat could conceivably mean that Titan — like many other moons circling other planets — is a source for unknown alien life forms.

The scientists, attending the American Geophysical Union’s annual meeting in San Francisco, presented reports on recent observations of Titan gathered by instruments aboard the Cassini spacecraft, which has been orbiting Saturn and flying past its 18 moons for more than four years.

For more than a year now, NASA teams viewing Titan’s cryptic surface from information received from far-off Cassini have puzzled over strangely alternating bright and dark spots along its equator, and what appeared to be sandy stretches and dunes — but without signs of a sea.

Detected by an instrument aboard the NASA spacecraft called a visual imaging mass spectrometer, or VIMS, episodes of brightness and darkness might well be violent upwellings from Titan’s interior, said Robert Nelson, a physicist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

“Looking down at Titan, the atmosphere is totally opaque,” Nelson said. “After the very first flyby, I looked at the surface and in spots along Titan’s equatorial region, it obviously had gotten brighter; it was the brightest thing we could see there.”

The scientists realized that something was turning two of those bright spots off during some of the flybys, and then turning them on again later, he said.

“Our VIMS spectrometer, gathering images in the infrared, told us it was ammonia being deposited over water ice,” Nelson said. “Ammonia was thought to exist on Titan only beneath the surface, and here it was: Ice thrusting up through the surface along with water, and probably methane too.”

Scientists believe that heat from Titan’s interior must be driving what they have termed the “cryovolcanoes,”

The science of the ultra-cold is called cryogenics, and at the temperature of Saturn’s moons about 93 degrees Kelvin, or nearly 300 degrees below zero Fahrenheit — “ice makes the best rocks you can have,” Nelson said.