It's a quarterly feast day for me: the day that the Cassini mission delivers three months' worth of data to NASA's Planetary Data System. Here's a few images processed from the October 1, 2012 data release.
Since Cassini currently orbits Saturn within the plane of Saturn's rings, it has lots of chances to catch two or more moons in the same photo. One such "mutual event" happened on September 17, featuring four moons: Titan, Dione, Pan, and Pandora.
About four years ago I wrote a blog entry about an ESA press release about paper published in Nature that suggested that Saturn's moons Tethys and Dione might have volcanic activity, like Enceladus. A new paper published in Icarus casts doubt on that conclusion.
I'm preparing a talk for the Pacific Astronomy and Telescope Show here in Pasadena on Sunday afternoon at 1:45. I have spent the morning putting together a slide that I have long wanted to have for presentations.
Last week I got very excited about a set of pictures that had appeared on Cassini's raw images website, but was sad that I couldn't make color versions myself. I was so excited that I failed to identify the little icy moon in the picture correctly.
It figures. I just start a three-week trip, with my only computer a diminutive Netbook, and guess what's just been radioed across the 1.3 billion kilometers separating us and Saturn? A set of photos that should become -- when properly processed -- an iconic image from Cassini's fourteen-year mission to the Saturn system.
I've got some lovely pictures from Saturn to show you! Every three months, the Cassini mission dumps gigabytes worth of precious Saturn data into the Planetary Data System, and the latest gift came on April 1. This particular pile of data, which was taken between April 1 and June 30, 2010, contains a lot of really terrific moon observations.
Daniel Macháček has reached into the dark side of Prometheus and pulled out an incredible amount of detail where the potato-shaped moon is illuminated by Saturnshine. He produced an animation that morphs among the three sets of four-filter color images that Cassini snapped during the flyby.