NASA's infra-red Spitzer Space Telescope has identified a vast, diffuse and all-but invisible new ring around Saturn, tilted at 27º from the main ring plane. The discovery was announced on 6 October 2009.

The huge disk of material starts about 6 million km away from the planet and extends at least another 12 million km outward, with a vertical thickness of about 2.5 million km. However, despite its size the ring is very tenuous, composed of highly diffuse ice and dust particles. This material is thought to have come from Phoebe, one of Saturn's most distant moons, as a result of small impacts on the moon's surface. This material may also solve the long-standing puzzle of the two-tone moon Iapetus, light on one side and dark on the other. It's thought that the dark face is caused by dust from the ring moving inwards towards Saturn and impacting the moon on one side.

Image: Artist's impression of new giant ring around Saturn (infrared view) (NASA)

View beautiful images of Saturn's other rings from the Cassini-Huygens mission, recently on display at the Royal Observatory, Greenwich.