JPL's Cassini Spacecraft Discovers 'A New Piece of the Puzzle' on Moon of Saturn

By City News Service

The JPL-managed Cassini spacecraft detected propylene—a common component of some plastic products—in a far-off place: the atmosphere of Titan, Saturn's largest moon, NASA announced Monday.

The composite infrared spectrometer aboard Cassini, which has been orbiting Saturn and its moons since June 2004, identified a small amount of propylene in the lower atmosphere of Titan.

Titan is the only moon in the solar system with a significant atmosphere, and astronomers consider the moon a time capsule that offers a look at what Earth may have been like before life developed.

Propylene "is all around us in everyday life, strung together in long chains to form a plastic called polypropylene," said Conor Nixon, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "That plastic container at the grocery store with the recycling code 5 on the bottom—that's propylene."

Cassini deputy project scientist Scott Edgington said the discovery offers a "a new piece of the puzzle (that) will provide an additional test of how well we understand the chemical zoo that makes up Titan's atmosphere."

Launched Oct. 15, 1997, the plutonium-powered Cassini is the most highly instrumented and scientifically capable interplanetary spacecraft ever deployed, NASA's Jet Propulsion Laboratory in Pasadena reported earlier. The spacecraft has compiled a long list of discoveries since going into orbit around the solar system's second largest planet.

The Huygens probe Cassini carried landed on Titan in January 2005 and sent back stunning images from the surface until it was overcome by the frigid cold two and a half hours later.

In 2005, Cassini also found possible evidence of liquid water just beneath the surface of Saturn's tiny, shiny moon Enceladus.  Cassini's instruments detected that water vapor geysers were shooting hundreds of miles into space from the moon's south pole.

The Cassini-Huygens mission is joint venture involving NASA, the European Space Agency and the Italian Space Agency.