Cassini visits a foamy moon

I’ve said it before: Saturn’s moon Hyperion is seriously freaky. New images from the Cassini spacecraft flyby of the tiny moon don’t change my mind one bit:

[Click to enchronosenate.]

What a weird place! Hyperion is a lumpy chunk of ice only about 270 km (170 miles) across on average, but yesterday (August 25, 2011) Cassini passed about 25,000 km away from it, so it got a lot of high-resolution shots.

As you can see, it’s saturated with craters. But they look funny! The overwhelming impression I get is that Hyperion is made of resilient foam, like a packing peanut. I’m also fascinated by the ginormous crater that dominates this face of the moon. If Hyperion were made of stiff rock, an impact that size would’ve shattered it like a bullet hitting a pebble. But if the composition of the moon is able to compress and compact — like foam, or something with lots of pockets of empty space inside it — the impact would do pretty much what we see here. Lots of asteroids appear to be "rubble piles" — chunks of material held together by their own …