This new image from the Cassini spacecraft shows the battered surface of Tethys, a moon of Saturn.

Tethys is about 659 miles (1,060 kilometers) wide. It is mostly color-free, as shown in this natural-color picture, the most detailed ever made.

The moon is nearly saturated with craters. Many small craters lie on top of older, larger ones, suggesting an ancient surface, scientists said earlier this week. At the top and along the boundary between day and night, the moon's terrain has a grooved appearance.

Tethys is known to have a density very close to that of water, indicating that it is likely composed mainly of water ice. Its frozen mysteries await a close flyby planned for Cassini next September.

-- SPACE.com Staff

Credit: NASA/Space Science Institute