This is an image of wrinkle ridges on the surface of Mercury. The photograph was taken by the Mariner 10 spacecraft.
Courtesy of NASA.
Wrinkle Ridges
Wrinkle ridges on the surface of Mercury are thought to have been
caused by the shrinking of the surface following the cooling and
shrinking of the core of the planet. As the core cooled and
shrank, the surface was forced to shrink also,
developing ridges which are scatterred across the planet.
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