expose-the-light:

Saturn’s Most Habitable Moon Offers Ice, Water, Killer Views

1. Enceladus’ southern tiger stripes are actively spewing jets of ice into space. The region is also anomalously warm relative to the rest of the planet, and releasing three times more heat than a similar sized area on Earth. Until recently, scientists didn’t know why.

A study in Nature Geoscience in January explains that the heat is caused by blobs of warmer ice moving toward the surface and pushing colder ice down. Scientists think these eras of churning ice last around 10 million years, while the intervening quiet times last 100 million to 2 billion years, so Cassini is lucky to have visited during one of the active times that make up between 1 and 10 percent of the moon’s history.

“Cassini appears to have caught Enceladus in the middle of a burp,” UC Santa Cruz planetary scientist Francis Nimmo, co-author of the new study, said in a press release. “These tumultuous periods are rare, and Cassini happens to have been watching the moon during one of these special epochs.”

2. Enceladus is the sixth largest of Saturn’s 62 moons. The plumes emanating from its southern pole are just visible in this image.

3. This spectacular image of Enceladus nestled next to Saturn below the planet’s rings was taken by Cassini on Christmas Day, 2009. It was captured by the spacecraft’s wide-angle camera from 384,000 miles away.

4. Here, Enceladus is speeding by Dione, a moon more than twice its size. Enceladus orbits faster and closer to Saturn than Dione. The ring is Saturn’s outermost F-ring.