Why not a constant early lunar impact rate?

• Main Author: Wilhelms, D. E.
• Format: Other/Unknown Material
• Language: unknown
• Published: 1985
• Subjects: 91; Aitken; South Pole; South pole
• Online Access: http://ntrs.nasa.gov/search.jsp?R=19850015225

Two distinct episodes of impacting are recorded on the Moon's surface. An early episode marked by an intense barrage that included basin-forming projectiles ended about 3.8 aeons ago when the Orientale basin was created. The second episode, after 3.2 or 3.3 aeons ago, was marked by a much lower...