BBC News - Moon formation: Was it a 'hit and run' accident?: Scientists have proposed a fresh idea in the long-running debate about how the Moon was formed.
What is certain is that some sort of impact from another body freed material from the young Earth and the resulting debris coalesced into today's Moon.
But the exact details of the impactor's size and speed have remained debatable.
In a report online to be published in Icarus, researchers suggest that the crash happened with a much larger, faster body than previously thought.
