The beautiful wispy terrain on Dione has long tantalized planetary scientists looking over low resolution images of the moon. When Cassini flew by Dione in December 16, 2004 it revealed the wisps to be bright ice cliffs created by the fracturing of the moon’s surface, a result completely unexpected by scientists. This would not be the last unexpected surprise.
On October 11, 2005, Cassini traveled even closer over Dione and sent back images of fantastic surface features that demand further scrutiny. Each raw image was more bizarre than the last: oddly shaped craters with dark material in their deepest reaches, fractures scratching the surface, and grooves that seem to ooze across the surface like toothpaste.
The questions, as usual for these Saturnian moons, come fast and furious in the face of such convoluted terrain. How did all of this happen? When did it happen and is the activity ongoing? Is Dione currently a world in turmoil or is it instead the dead remains of a world scrambled very early in its history?
Cassini will continue to seek answers with several more flybys of Dione over the next few years.