One of Hoagland's more interesting theories is that Mars was once a moon of Planet "V" that later exploded. He makes a very good case.
However, he lost me way back when he claimed there was remnants of a glass dome on the Moon, and you could see them in NASA Moon photos. Therefore I don't care if he is right or not about Mars, he's a (with apologies to waterfowl everywhere) at total LOON.
