APOD: 2021-05-31 - Mimas: Small Moon with a Big Crater (Narrated by Emma)

Astronomy Picture of the Day - May 31st, 2021 - Mimas: Small Moon with a Big Crater (Narrated by Emma) 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 Image Credit & Copyright: NASAJPL-CaltechSpace Science InstituteCassini Source: https://apod.nasa.gov/apod/ap210531.html This video was auto generated using data from NASA Open API.