THE moon has been hiding the scars of its violent, asteroid-filled past.
Most surveys of lunar impact craters have used photos, but of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, wanted to know if there were any old craters buried beneath younger ones. So he studied elevation mapping data from the Clementine mission in the 1990s. He also used simulations to identify impact signatures, such as a roughly circular crater with a thin crust and a thicker rim. This approach uncovered 150 craters more than 300 kilometres wide instead of 45.
Frey is now trying to work…
