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July 15, 1995
The Crater Chain
Picture Credit: NASA, Voyager Team
NASA's robot spaceprobe
took this closeup image of the surface of Jupiter's crater scarred moon
Callisto in 1979. A mysterious chain of craters is seen to extend diagonally
across the image (upper left to lower right). What could cause the craters
to line up in such a regular fashion? Scientists were at a loss to explain
this crater chain along with several other chain like features observed
on Callisto's surface. Fifteen years later, with the discovery of
Comet Shoemaker-Levy 9,
also known as the
"string of pearls" comet,
the mystery was solved. Comets whose orbits stray too close to
Jupiter are torn apart by the strong gravity.
When the individual pieces, strung
out along the orbital path of the comet hit an object like Callisto,
the sequence of impacts produces a crater chain.
Tomorrow's picture: The Exploration of Mars
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