This image of Saturn’s seventh largest moon, Mimas, was photographed when NASA’s Cassini spacecraft was approximately 115,000 miles (185,000 km) away.
NASA’s Cassini spacecraft obtained this image of Mimas on Oct. 22, 2016. Image credit: NASA / JPL-Caltech / Space Science Institute.
Mimas, also known as Saturn I, is the innermost and smallest of Saturn’s main moons.
It was discovered on Sept. 17, 1789 by English astronomer William Herschel and named for one of the Giants of Greek mythology.
Mimas is approximately 246 miles (396 km) across.
It revolves around Saturn in a prograde, near-circular orbit at a mean distance of about 117,000 miles (189,000 km).
Because of tidal interactions with Saturn, Mimas rotates synchronously with its orbital motion, always keeping the same hemisphere toward the planet and always leading with the same hemisphere in orbit.
Mimas’ surface is icy and heavily cratered.
One of the craters, Herschel, is surprisingly large in comparison to the size of the icy moon.
Named after the moon’s discoverer, the crater stretches roughly 81 miles (130 km) wide — almost one-third of the diameter of Mimas itself.
Large impact craters often have peaks in their center. Herschel’s peak stands nearly as tall as Mount Everest on Earth.
This image was taken with Cassini’s narrow-angle camera on Oct. 22, 2016, using a combination of filters which preferentially admits wavelengths of UV light centered at 338 nm.
