What lies at the bottom of Hyperion's strange craters?
No one knows.
To help find out, Cassini took this image, containing unprecedented detail, as the spacecraft swept past the sponge-textured moon in late 2005.
The image shows a remarkable world strewn with strange craters and odd surfaces.
At the bottom of most craters lies some type of unknown dark material.
Inspection of the image shows bright features indicating that the dark material might be only tens of meters thick in some places.
Hyperion is about 250 kilometers across, rotates chaotically, and has a density so low that it might house a vast system of caverns inside.
Image credit: NASA, ESA, JPL, SSI and Cassini Imaging Team