Are the blue patches evidence of a ring around Rhea? Credit: NASA/JPL/Space Science Institute/Universities Space Research Association/Lunar & Planetary Institute

Does Saturn’s second largest moon Rhea really have a ring?   A ring has never been actually seen, but there is a narrow 10 km wide band of bluish patches straddling the moon’s equator.

The picture above was produced by Dr. Paul Schenk of the Lunar and Planetary Institute using stereo topography from Cassini imaging data in 2008.

The idea is the bluish material is fresh ice exposed when debris from “the ring” struck the moon.

There was a close flyby of Rhea the day after this image was released.  Since I’m a skeptical sort,  I am waiting for that data.  If blue patches go all the way around the moon, they could be on to something.  Rhea is phase locked to Saturn the same way our moon is to Earth.  So it presents the same face towards the planet.  It would seem to me that if the blue patches go all the way around the moon, they aren’t simply the moon plowing through stray bits of debris from Saturn’s rings.

A moon with a ring….

See the original press release here.