Herschel is a huge crater on the Saturnian moon Mimas. It is named after the eighteenth century astronomer William Herschel, who discovered Mimas in 1789. The crater is so large that it is surprising that Mimas was not shattered by the impact that caused it. It measures 130 km across, covering almost 1/3 of the diameter of the entire moon; its walls are approximately 5 km high, parts of its floor are 10 km deep, and its central peak rises 6 km above the crater floor. If there were a crater of an equivalent scale on Earth it would be over 4,000 km in diameter, wider than Canada. The impact that formed Herschel must have nearly disrupted Mimas entirely; fractures can be seen on the opposite side of Mimas that may be due to the shock waves from the impact travelling through the moon's body. Below, are photos from the Cassini probe to Saturn of both the massive crater on one side, and what appears to be faint stress marks on the satellite's opposite side when the body most likely came close to being disintegrated by the impact. The similarity between Mimas's appearance and the Death Star in Star Wars has often been noted, although this is a coincidence, as the crater was not discovered until several years after the film was made.
