December 13, 2017

24.10.09: Enceladan Seas?

Move over Europa ; yet another moon may harbor a subsurface sea. Saturn’s moon Enceladus has been inching its way up the charts as of late as a candidate world for extraterrestrial life. Barely 300 miles in diameter, the tiny world is repeatedly flexed by Saturn’s gravity and an increased orbital eccentricity pumped up by the nearby moon Dione. This has caused the tiger-striped surface seen by the Cassini space probe, a surface that shows evidence of repeated fissuring and freezing that almost certainly covers a liquid interior. In fact, Cassini has caught several of the geysers in the act during four recent flybys of the moon. One flyby was close enough that Cassini actually flew through a geyser plume! Activity on Enceladus is now known to almost exclusively contribute to Saturn’s E ring…and recently, a much broader ring system has been revealed by the Spitzer space telescope. Sodium chloride has also been detected in the E ring, presumably from the interior of Enceladus…clearly, the Saturnian system is a dynamic place warranting more scrutiny. Let’s hope that NASA approves Cassini’s seven year mission extension!