The "man in the moon" appeared when meteoroids
struck the Earth-facing side of the moon creating large flat seas of basalt
that we see as dark areas called maria. But no "face" exists on
farside of the moon and now, Penn State astrophysicists think they know why.
"I remember the first time I saw a globe of the moon as
a boy, being struck by how different the farside looks," said Jason Wright,
assistant professor of astrophysics. "It was all mountains and craters.
Where were the maria? It turns out it's been a mystery since the fifties."