Just in case you need reminding how nice a place to live Earth is.

When all is said and done, the outer solar system must be a pretty scary place to live. How’d you like to live in a location that has a battle-scarred history like this?

That’s Saturn’s moon Dione as seen in by the space probe Cassini in a recent pass of the small world. Earlier today (September 4, 2010), Cassini dipped to a height of less than 40,000 km (25,000 miles) above Dione’s surface — that’s about the same height as weather satellites above the surface of the Earth!
The landscape of Dione is shockingly battered. Craters are everywhere, indicating a fierce history of meteoric bombardment. It is also heavily littered with cliffs and chasms.
I learned something incredibly interesting looking up information about the moon: like all moons in the solar system, it’s tidally locked with its parent planet, meaning it spins at the same rate it orbits, always showing the same face to Saturn. This is a natural consequence of gravity and isn’t terribly surprising. What did surprise me is that the trailing hemisphere of Dione is more heavily cratered than the leading hemisphere!
Because of its spin-orbit coupling, Dione always has the same half of its surface pointing ...