Astrophysics study suggests Venus may have swallowed its moon

A California-based astrophysicist presented a new theory on Monday to explain why Venus, the planet most like Earth in size, mass and structure, lacks its own moon. Call it a case of celestial cannibalism.

The extremely slow speed at which Venus rotates on its axis would have doomed any natural satellite that may once have orbited that planet to gradually spiral closer to its parent and ultimately be consumed in a cataclysmic smash-up.

So goes the theory offered by scientists at the University of California, Riverside, and published on Monday in The Astrophysical Journal, marking a departure from past explanations for why Venus, the second planet from the sun, is without a lunar companion.