Transcription: From above Valhalla we can see a giant bullseye, a bright circular crater about 600 km in diameter, but it is the system of rings surrounding the basin which is so striking. The largest of these rings are up to 3000 km in diameter. Yet note once again that there are no true highlands. This sort of terrain is limited to bodies with surfaces made of a mixture of rocks and ice. The Valhalla Basin is unique. There is nothing else quite like it in the solar system. It must have been remarkable to see a meteorite, only a couple of kilometers wide, hurtling toward Callisto and crashing into the surfa ... File Comment Made in Intimate Arts
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