It is not quite big enough to hold a round shape, so it is somewhat ovoid with dimensions of x x miles x x kilometers, respectively. Its low density suggests that it consists almost entirely of water ice, which is the only substance ever detected on Mimas. At a mean distance just over , miles , kilometers from the massive planet, Mimas takes only 22 hours and 36 minutes to complete an orbit.
Mimas is tidally locked: it keeps the same face toward Saturn as it flies around the planet, just as our Moon does with Earth. Most of the Mimas surface is saturated with impact craters ranging in size up to greater than 25 miles 40 kilometers in diameter. However, the craters in the South Pole region of Mimas are generally This suggests that some melting or other resurfacing processes occurred there later than on the rest of the moon.
Interestingly, the South Pole area of Enceladus appears to be the source of that moon's geysers. Its most distinguishing feature is a giant impact crater — named Herschel after the moon's discoverer — which stretches a third of the way across the face of the moon, making it look like the Death Star from "Star Wars.
The impact that blasted this crater out of Mimas probably came close to breaking the moon apart. Shock waves from the Herschel impact may have caused the fractures, also called chasmata, on the opposite side of Mimas. That Mimas appears to be frozen solid is puzzling because Mimas is closer to Saturn and has a much more eccentric elongated orbit than Enceladus, which should mean that Mimas has more tidal heating than Enceladus. Yet Enceladus displays geysers of water, which implies internal heat, while Mimas has one of the most heavily cratered surfaces in the solar system, which suggests a frozen surface that has persisted for enough time to preserve all those craters.
This paradox has prompted the "Mimas Test" by which any theory that claims to explain the partially thawed water of Enceladus must also explain the entirely frozen water of Mimas.
The mythological Mimas was a giant who was killed by Mars in the war between the Titans and the gods of Olympus. Even after his death, Mimas' legs — which were serpents — hissed vengeance and sought to attack his killer.
Mimas was named by John Herschel, the son of discoverer William Herschel, who explained his choice of names for the first seven of Saturn's moons to be discovered by writing, "As Saturn devoured his children, his family could not be assembled round him, so that the choice lay among his brothers and sisters, the Titans and Titanesses. Astronomers also refer to Mimas as "Saturn I" based on its distance being the closest to Saturn.
The International Astronomical Union now controls the official naming of astronomical bodies. Overview Less than miles kilometers in mean radius, crater-covered Mimas is the smallest and innermost of Saturn's major moons. A 3D model of Mimas, a moon of Saturn. This page showcases our resources for those interested in learning more about Saturn and Titan.
Saturn and Titan Resources. JPL's lucky peanuts are an unofficial tradition at big mission events. According to legend, Mimas' serpent legs continued to hiss after his death, seeking vengeance on his killer. The island of Prochyte, which lies near Sicily, is said to rest on his body. Mimas has one of the most heavily cratered surfaces in the solar system. The overlapping depressions cover the surface, with several reaching sizes of 25 miles 40 kilometers in diameter.
Many of these overlap. In the south pole, however, craters are smaller than The most noticeable sign of impact is the gaping Herschel crater, which spreads across an enormous portion of the satellite. At 88 miles km across, the crater covers nearly a third of the moon's mile km diameter. A similarly sized crater on Earth would be 2, miles 4, km in diameter. Scientists think that the impact nearly demolished the tiny moon; shock waves from the crash appear on the far side of the satellite.
The giant bulls-eye gives the crater a similar appearance to the Death Star. The resemblance is coincidental, however; Mimas is so small that features on it weren't seen until the Voyager space probe spotted it in , three years after the blockbuster "Star Wars" premiered. A temperature map created by data from NASA's Cassini spacecraft also reveals a Pac-Man shaped figure , seemingly prepared to gobble up the massive crater. Temperatures around the crater are cooler than more distant regions of the moon, with a warm spot showing up at the crater itself.
A similar shape shows up on another of Saturn's moons, Tethys. The iconic configuration could occur as high-energy electrons bombard the leading edge of the satellites in their orbits, turning it into hard-packed ice that shifts its temperature more slowly than other parts of the moons. Although the moon is the smallest of Saturn's major satellites, it apparently cleared sufficient material to create the 2,mile 4,km wide gap between the two largest rings.
Traveling only , miles , km from Saturn, Mimas is the closest major moon orbiting the planet. It journeys around the giant once every 22 hours and 37 minutes, keeping one face perpetually turned toward its primary. The density of the moon is only 1. At temperatures of minus degrees C minus degrees F , the frozen surface behaves much like rock. Mimas has a slightly elliptical orbit, which should cause more tidal heating in its interior. It lies closer than its fellow moon, Enceladus.
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