Two tiny moons lost among the rings of Saturn

Image: NASA/JPL-Caltech/Space Science Institute.
Image: NASA/JPL-Caltech/Space Science Institute.

Two tiny moons of Saturn, almost lost amid the planet’s enormous rings, are seen orbiting in this Cassini probe image. Pan, visible within the Encke Gap near lower-right, is in the process of overtaking the slower Atlas, visible at upper-left.

All orbiting bodies, large and small, follow the same basic rules. In this case, Pan (28 kilometres or 17 miles across) orbits closer to Saturn than Atlas (30 kilometres or 19 miles across). According to the rules of planetary motion deduced by Johannes Kepler over 400 years ago, Pan orbits the planet faster than Atlas does.

This view looks toward the sunlit side of the rings from about 39 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on 9 July 2016.

The view was acquired at a distance of approximately 5.5 million kilometres (3.4 million miles) from Atlas and at a Sun-Atlas-spacecraft, or phase, angle of 71 degrees. Image scale is 33 kilometres (21 miles) per pixel.

Saturn: Exploring the Ringed Planet

Find out more about Saturn and its moons in this 196-page special edition from Astronomy Now. [geot exclude_region=”US” ]Order from our online store.[/geot][geot region=”US” ]Order from our online store.[/geot]