Astronomy Picture of the Day
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October 15, 1995
Iapetus: Saturn's Disappearing Moon
Iapetus has an unusual surface, one half of which is very dark, the other
half very light. This caused it's discoverer
Cassini to remark that
Iapetus could only be seen when on one side of Saturn but not the other.
The reason for the difference between hemispheres is presently unknown.
Iapetus is the third largest of
Saturn's moon behind
is composed predominantly of water ice.
Tomorrow's picture: Starburst Galaxy M94
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