Men are from Mars and women are from Venus, but only Miss Cleo could confirm that.
The commonly used symbol for man is the astrological sign of Mars. The relationship between the gender and the planet, however, doesn't appear to have an academic basis.
"Mars is the Roman god of War," says Head of the Department of Greek and Roman Studies Dr. Peter Toohey. "He is the force of war, mayhem, and violence but is no more of a man than any of the other male gods."