Terrestrial planet impacts     Here are scale topographic images of the Moon (top) and Mars (bottom), centered on what are the largest known impact basins on the terrestrial planets: the South Pole-Aitken basin on the Moon and the Hellas basin on Mars. (The black area on the Moon image is 10° around its southern pole where Clementine was not able to measure the lunar topography.) The Hellas impact deposited a ring of ejecta around it about 2 km thick, shown here as the dark-green ring around the basin. I don't know if anyone has modeled the South Pole-Aitken impact, but it would be interesting to see whether or not most of the ejecta was simply blasted off the Moon. It's also interesting that both of these basins are elongated, perhaps implying an oblique impact angle for both.

These scale images were made assuming a mean radius of 1738 km for the Moon and 3396 km for Mars.

Comments, questions, problems about Jules Verne Voyager? Send mail to Lou Estey
(louunavco.org)