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.

2010 May 11
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Herschel Crater on Mimas of Saturn
Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA

Explanation: Why is this giant crater on Mimas oddly coloured? Mimas, one of the smaller round moons of Saturn, sports Herschel crater, one of the larger impact craters in the entire Solar System. The robotic Cassini spacecraft now orbiting Saturn took the above image of Herschel crater in unprecedented detail while making a 10,000-kilometre record close pass by the icy world just over one month ago. Shown in contrast-enhanced false colour, the above image includes colour information from older Mimas images that together show more clearly that Herschel's landscape is coloured slightly differently from more heavily cratered terrain nearby. The colour difference could yield surface composition clues to the violent history of Mimas. An impact on Mimas much larger than the one that created the 130-kilometre Herschel would likely have destroyed the entire world.

Tomorrow's picture: big ball of stars


< | Archive | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.