A busy day for Cassini: Dione plus bonus Enceladus and Janus

Posted by Emily Lakdawalla

2010/04/08 12:39 CDT

Topics:

The Cassini Saturn orbiter just completed its second very close flyby of Saturn's mid-sized iceball moon Dione, and the images from that encounter have been streaming onto the Cassini raw images website this morning. There are some spectacular pictures. Here's a mosaic composed of two images shot across Dione's limb, capturing both the cratered surface and the fractures that cut it.

NASA / JPL / SSI / mosaic by Emily Lakdawalla

Dione's limb

Cassini gazed across Dione's limb on April 7, 2010 to capture the two images that were composed into this view. It shows Dione's cratered surface dissected by bright-walled fractures.

And here are two ultra close-ups one showing cratered terrain and one showing fractures. At the time Cassini took these pictures, it was not doing any fancy turns to point at the surface; the spacecraft was in a fixed orientation advantageous for its "fields and particles" instruments, the ones that sense the magnetic field and sniff out the gases and dust particles that may be in the space close to Dione. But those tricky Cassini planners managed to leave the spacecraft in an orientation such that the field of view of the camera and other optical instruments was dragged across the surface of the moon as it flew past, and they snapped image and other data at opportune moments.

Dione closeup

That's not all Cassini did yesterday. It also happened to fly pretty close to Janus, Epimetheus, and Enceladus. I think this is a particularly nice point of view on Enceladus, at almost perfectly 90 degrees phase, covering the cratered terrain near its north pole, the ridges near the equator, and the tiger stripe terrain near the south pole.