During the 1960s, Apollo mission planners worried that the landers might crash due to odd gravity fluctuations they found on the moon. NASA has discovered the source of these gravity fluctuations, thanks to the recent GRAIL mission. GRAIL’s twin spacecraft pinpointed dense regions called mass concentrations, or mascons, which exert strong gravitational pulls.
The patterns GRAIL found indicate the interior of the moon was significantly warmer during asteroid bombardment over 3 billion years ago than it is now.
“Understanding mascons may teach us more about the ancient Earth, perhaps about how plate tectonics got started and what created the first ore deposits. This new understanding of lunar mascons also is expected to influence knowledge of planetary geology well beyond that of Earth and our nearest celestial neighbor,” says NASA.