Cassini spacecraft
Saturn's Rings
Saturn's Moon Enceladus
Surface of Saturn's Moon Enceladus
Jets of material from Enceladus reach into the F-ring of Saturn
Cassini spacecraft

Cassini spacecraft

Courtesy of NASA

Cassini is a joint project of NASA, the European Space Agency and the Italian Space Agency. Cassini was launched and sent on an initial mission to study Saturn and its moons. The spacecraft had two parts—the orbiter Cassini and the probe Huygens. Huygens parachuted down to Titan’s surface (one of Saturn’s moons) in 2005 to study the atmosphere and returned data for 2 1/2 hours. The Cassini orbiter has extended its mission several times and continues to operate on the Solstice Mission, which is not scheduled to end until 2017.

October 15, 1997

June 30, 2004; (Huygens on Titan) January 14, 2005

End of Mission
Still operating

Conduct a detailed study of Saturn and its moons, including temperature and composition of Saturn’s atmosphere, cloud properties, winds, internal structure, its rings, icy moons, and deploy Huygens probe to plunge through the atmosphere of Titan. The mission was extended to study Saturn’s northern hemisphere and the rings’ northern face and further study Titan and Enceladus.

Cassini recorded powerful lightning storms; 10,000 times stronger than those on Earth. These storms occurred in huge, deep thunderstorm columns nearly as large as the entire Earth. Auroras on Saturn continue for days rather than minutes or hours like on Earth. The wind speeds recorded by Cassini are different from those found by Voyager—Saturn may lose its place as the windiest planet in the solar system.

Rings: Cassini found several times the amount of matter in the densest rings than previously measured. It discovered entirely new kinds of channel-like structures within the rings. It found small moonlets within strands of ring material producing complicated, shifting patterns. It discovered that the stranded F-ring has changed since Voyager studied it. The craft discovered a new moonlet clearing its own empty gap in the A-ring. It found objects no larger than a football field buried deeply in the A-ring. The most common materials within the rings are meter-sized.

Enceladus: Liquid water may be just beneath the surface. The craft discovered geysers of water-ice jetting a distance three times the diameter of Enceladus. Particles from these geysers are becoming part of Saturn’s rings.

Titan: Images of Titan show what Earth might have been like before life evolved. Like Earth, Titan has lakes, rivers, channels, dunes, rain, snow, clouds, mountains, and possibly volcanoes. But unlike Earth, Titan’s lakes, rivers and rain are made of methane and ethane, at –179°C.