They'll be looking for answers after two NASA GRAIL probes enter orbit around the moon this weekend.
If such a crash occurred, remnant radioactive materials such as uranium and thorium may be buried inside the moon and serve as evidence of a crash.
Scientists in a recently published paper say they suspect a second moon once circled the Earth in the same orbit as the moon.
They think the two collided and the second moon created a mountain on the side of the moon that always faces away from Earth.
(Copyright 2011 by VERTEXNews/Newsroom Solutions)