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Enceladus and Cassini
A tiny moon, 153 miles across, orbits Saturn from 238,020 kilometers away in the cold, dark depths of the solar system. Its surface temperature is a rather chilly -330 degrees Fahrenheit, and its name is Enceladus, discovered in 1789 by William Herschel. Enceladus is intriguing: it reflects nearly 100 percent of the light it receives from the sun, it is made up of five different kinds of terrain, and it is one of the few moons with active icy eruptions. The spacecraft, Cassini, has been keeping watch over Enceladus since 2005.
Cassini was launched in October of 1997 and arrived at Saturn in 2004. This spacecraft was intended to uncover some of the many mysteries of Saturn and its moons. It has already flown past Enceladus on several occasions, but the most recent flyby occurred on August 11, 2008. During this approach, Cassini passed a mere thirty miles above Enceladus in hopes of learning more about the "tiger stripe" fissures at the south pole, a region where icy jets erupt from the surface of the moon. Speeding at 40,000 miles per hour, Cassini was able to quickly pinpoint and capture pictures of the tiger stripes. These images will unlock some of the secrets behind Enceladus' eruptions.
Later, on an October 8 flyby, the spectrometer on Cassini collected data on the vapors and ices of Enceladus and found several organic compounds, including ammonia. Ammonia is important because it can keep water in a liquid state under very cold temperatures. So, deep within Enceladus' interior, it could contain liquid water.
Cassini also passed by Enceladus on October 31, 2008.
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