The Associated Press
WASHINGTON — In a spectacle that might have beguiled poets, lovers and songwriters if only they had been around to see it, Earth once had two moons, astronomers now think. But the smaller one smashed into the other in what is being called the "big splat."
The result: Our planet was left with a single bulked-up and ever-so-slightly lopsided moon.
The astronomers came up with the scenario to explain why the moon's far side is so much more hilly than the one that is always facing Earth.
The theory, outlined Wednesday in the journal Nature, comes complete with computer model runs showing how it might have happened and an illustration that looks like the bigger moon getting a pie in the face.
Outside experts said the idea makes sense, but they aren't completely sold yet.
This all supposedly happened about 4.4 billion years ago, long before there was any life on Earth to gaze up and see the strange sight of dual moons. The moons themselves were young, formed about 100 million years earlier when a giant planet smashed into Earth. They both orbited Earth and sort of rose in the sky together, the smaller one trailing a few steps behind like a little sister in tow.