Moon Tethys 'Hangs' Off Saturn's Rings

In a stunning photograph beamed back to Earth from NASA’s Cassini spacecraft, one of Saturn’s moons appears to ‘hang’ off the gas giant’s rings like a water droplet.

The icy moon Tethys is approximately 660 miles wide and is composed of similar material as the rings it is orbiting behind. Cassini snapped the moon with its narrow-angle camera on July 14 at a distance of 1.1 million miles.

In the foreground, two of Saturn’s rings — the A and F rings — overlap Tethys from Cassini’s perspective. The F ring is Saturn’s outermost ring and is separated from the A ring by a gap of 1,900 miles — known as the Roche Division. Embedded in the A ring, overlapping Tethys, is a very thin 26 mile separation called the Keeler Gap that is kept clear by the tiny moon Daphnis, which is out of shot.

Although the A ring seems to overlap Tethys, the moon actually orbits Saturn nearly 100,000 miles higher than the ring.

Cassini has been orbiting Saturn for over ten years, transforming our view of the gas giant, its rings and extensive family of moons. Sadly, as the spacecraft runs low on thruster fuel, mission scientists are beginning to plan for mission end. More details on Cassini’s “Grand Finale” mission can be read here.

From Discovery News