APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Mimas: Small Moon with a Big Crater
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 .
Interactive: Take a trek across Mimas
| Date | May 31, 2021 |
|---|---|
| Credit | Image Credit & Copyright: NASA , JPL-Caltech , Space Science Institute , Cassini |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |