Saturn's UFO moons: Bizarrely-shaped Pan and Atlas baffle scientists

By Daily Mail Reporter

Last updated at 3:51 PM on 18th March 2011

They look more like flying-saucers than icy moons, but Pan and Atlas are two of Saturn's strangest satellites.

Scientists have long been puzzled by how the oddly-shaped moons, which are only 20miles across, came to be.

Researchers based at the European Space Agency now think they have some answers after studying several years worth of cosmic images.

UFO? Pan is Saturn's most inner moon, as seen in this illustration. It orbits within the Encke Gap in the planet's A ring

They realised that 14 of Saturn's small moons had a very low density - about half that of water ice - and shapes that suggested they had grown out of the rings themselves.

However, they would have needed a jump start as it is not gravitationally possible for small particles to fuse together within the rings.

Therefore, each moon would have started with a massive core that was a leftover from the original collisions that caused the rings.