Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2006 June 27
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

The Moving Moons of Saturn
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: The moons of Saturn never stop. A space traveler orbiting the ringed giant planet would witness a continuing silent dance where Saturn's multiple moons pass near each other in numerous combinations. Like a miniature Solar System, the innermost moons orbit Saturn the fastest. The above movie was centred on Saturn's moon Rhea, so that the moons Mimas and Enceladus appear to glide by. At 1,500 kilometres across, Rhea is over three times larger than the comparably sized Mimas and Enceladus. The Sun illuminates the scene from the lower right, giving all of the moons the same crescent phase. The above time lapse movie was created by the Saturn-orbiting robotic Cassini spacecraft over a period of about 40 minutes.

Tomorrow's picture: red paw


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