The US landed humans on the Moon 6 times 1969-1972 during the Apollo Program . No further spacecraft studies until 1990's. Click for larger view and information. Captured satellites exist but small Collisional ejection. Declines with time.
Large impacts penetrate surface, allow lava upwelling to form maria.
3-3.8 Byr ago. History, Info, Photos, Other data. All rights reserved. These notes are intended for the private, noncommercial use of students enrolled in Astronomy 121 at the University of Virginia. Reproduction, distribution, and commercial uses are prohibited.