Ghost crater

The great crater of the moon Ptolemy . In the 150 km large whale plain , on the right - above the small hole crater - in the shallowly incident light, there is a larger ghost crater. Some are also faintly visible on the left, in the center of the picture.

In astronomy, an old impact crater is referred to as a ghost crater , the crater wall of which has been almost completely eroded by long-term erosion and is only visible when the sun is very flat (see pictures).

The 30 km crater Lambert, photographed from Apollo 15 orbit . Below Lambert a ghost crater with a completely flat bottom, in the upper left part of a dorsal circle .

Even more recent impacts can lead to the overprinting of the old structures, which, however, can often be detected with special methods due to their rock-typical, spectral properties. The planetologist Eugene Shoemaker therefore also calls them palimpsests - analogous to the overwritten parchments in archeology.

Web links

• Ghost crater on Mars Article in the Frankfurter Rundschau from October 26, 2009.

literature

• J. Kelly Beatty, Brian O'Leary, Andrew Chaikin: The Sun and Its Planets. Space research in a new dimension (“The new solar system”). New edition Physik-Verlag, Weinheim 1985, ISBN 3-87664-056-3 .
• Antonín Rükl : Moon, Mars, Venus. Pocket atlas of the closest celestial bodies . Dausien Verlag, Hanau 1977, ISBN 3-7684-2795-1 .