This newly released image from NASA’s Cassini spacecraft shows two of Saturn’s moons, Mimas and Pandora, and the planet’s rings.
Although Mimas and Pandora, shown here, both orbit Saturn, they are very different moons. The shapes of moons can teach planetary scientists much about their history. This image was captured on July 26, 2015, when Cassini was nearly 904,000 miles (1.4 million km) from Mimas and 485,000 miles (781,000 km) from Pandora. 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 in 1789 by the English astronomer William Herschel and named for one of the Giants of Greek mythology.
The moon is 246 miles (396 km) in diameter and revolves around Saturn in a prograde, near-circular orbit at a mean distance of about 117,000 miles (189,000 km).
The moon’s surface is icy and heavily cratered. Many of the impact craters have central peaks.
One of the craters, Herschel, is surprisingly large in comparison to the size of the moon. It is roughly 81 miles (130 km) wide, one-third the diameter of Mimas.
According to a recent study, Mimas has either a rugby ball-shaped rocky core or an underground ocean.
Pandora, also known as Saturn XVII, is a small, inner moon of Saturn. In mythology, Pandora was a work of art who was transformed into a human by the gods.
The moon was discovered in 1980 from images taken by NASA’s Voyager 1 spacecraft.
It is about 50 miles (81 km) across and is elongated and irregular in shape. One explanation for its elongated shape and low density is that it may have formed by gathering ring particles onto a dense core.
The moon orbits Saturn every 15.1 hours at a distance of 88,048 miles (141,700 km).
This new image was taken in visible light with Cassini’s narrow-angle camera on July 26, 2015. The view looks toward the unilluminated side of Saturn’s rings from 0.26 degrees below the ring plane.
