APOD: Janus- Potato Shaped Moon of Saturn

Janus is one of the smaller moons of Saturn, in fact it is the 10th largest moon. Irregularly shaped, it is 190 km at its largest diameter. Janus has a sister moon, Epimetheus, they both share practically the same orbit only 30-50 km apart. Every four years the two moons head towards each other but instead of colliding they exchange orbits. They are about 91,000 km above the surface of Saturn and travels within the gap of the F and G rings. They are believed to also play a role in maintaining the outer age of the A ring.
The moon is photographed in front of Saturn. The Picture was taken from the Cassini satellite orbiting the planet.