Mimas: Small Moon with a Big Crater

Mimas: Small Moon with a Big Crater

Image Credit:
NASA,
JPL-Caltech,
Space Science Institute,
Cassini

Explanation:
Whatever hit Mimas nearly destroyed it.

What remains is one of the
largest impact craters on one of
Saturn‘s smallest round moons.

Analysis indicates that a slightly larger impact would have destroyed
Mimas entirely.

The huge crater, named
Herschel after the 1789 discoverer of Mimas,
Sir William Herschel, spans about 130 kilometers and is
featured here.

Mimas‘
low mass produces a
surface gravity
just strong enough to create a
spherical body but weak enough to allow such relatively large surface features.

Mimas is made
of mostly water ice with a smattering of rock – so it is
accurately described as a big dirty snowball.

The featured image was taken during the closest-ever flyby of the
robot spacecraft Cassini past Mimas in 2010 while in orbit
around Saturn.