Gravitational tugs on a pair of spacecraft have revealed previously unseen blemishes on the moon’s face.
Evidence of three new basins comes from gravity data collected by NASA’s GRAIL mission in 2012 (new basins circled in black, redder colors indicate a greater gravitational tug). The data provide a clearer picture of dents on the moon’s surface formed by impact craters, researchers report October 30 in Science Advances. These basins are often obscured by subsequent impacts and volcanic activity from the moon’s active youth.
These and other lunar craters spotted by GRAIL cast doubt that the Earth and moon were pummeled by rocks from the main asteroid belt some 4 billion years ago, a salvo dubbed the Late Heavy Bombardment. The sizes of these craters don’t match those expected from main-belt asteroids, the researcher say.