Herschel () is the largest impact crater on Saturn's moon Mimas. It is located on Mimas's leading hemisphere, centered on the equator at 112° longitude. It is named after the 18th-century astronomer William Herschel, who discovered Mimas in 1789.
Geology
Herschel is the second-largest crater relative to its parent body of any equilibrium planetary moon in the Solar System after Tethys's crater Odysseus.Craters on small moons such as Stickney may be comparably large ; the moons of dwarf planets have not been imaged. It is so large that astronomers have expressed surprise that Mimas was not shattered by the impact that caused it. It measures across, almost one third the diameter of Mimas. Its walls are approximately high, parts of its floor are deep, and its central peak rises above the crater floor.
Origin The impact that formed Herschel must have nearly disrupted Mimas entirely. Large chasms (termed chasmata) that may be stress fractures due to shock waves from the impact traveling through it and focusing there can be seen on the opposite side of Mimas. The impact is also suspected of having something to do with the current "Pac-Man"–shaped temperature pattern on Mimas. Herschel has an estimated age of around 4.1 billion years. it is also estimated that the impactor had a mean diameter of , and had a speed of 15 km/s.
Media reception The similarity between Mimas's appearance and the Death Star in Star Wars: Episode 4 due to the large size of Herschel has often been noted, both in the press and in NASA/JPL press releases. This is a coincidence, however, as the crater's similarities were not discovered until 1980 when Voyager 1 gained line of sight, three years after the movie was made.
See also Pharos – a similarly sized crater on Proteus List of largest craters in the Solar System List of tallest mountains in the Solar System
References
External links
- featuring the Voyager 1 image
- different photo than the 1995 one with the same title, features the Cassini image