WASHINGTON (TIP): Moon may have been created about 4.47 billion years ago, according to a new study of meteorites that provides clues to the giant collision which formed Earth and the lunar body.
A giant impact between a large protoplanet and the proto-Earth formed the Moon. The timing of this giant impact, however, is uncertain, with the ages of the most ancient lunar samples returned by the Apollo astronauts still being debated.
Research indicates numerous kilometre-sized fragments from the giant impact struck main belt asteroids at much higher velocities than typical main belt collisions, heating the surface and leaving behind a permanent record of the impact event.
Collisions on these asteroids in more recent times delivered these shocked remnants to Earth, which scientists have now used to date the age of the Moon.
By modelling the evolution of giant impact debris over time and fitting the results to ancient impact heat signatures in stony meteorites, the team was able to infer the Moon formed about 4.47 billion years ago, in agreement with many previous estimates.