A gravity map of the moon made by the Lunar Prospector spacecraft in 1998-99. Mascons are shown in orange-red. The five largest all correspond to the largest lava-filled craters or lunar "seas" visible in binoculars on the near side of the Moon: Mare Imbrium, Mare Serenitatus, Mare Crisium, Mare Humorum and Mare Nectaris. Credit: Alex S. Konopliv et al, Icarus 150, 1–18 (2001)
