(CNN) When the Apollo 14 astronauts returned samples from the moon's surface, they probably didn't realize that they were reuniting Earth with a bit of its early history.

The "moon rock" probably collided with the moon after an impact sent it hurtling from Earth 4 billion years ago, according to research published Thursday in the journal Earth and Planetary Science Letters

The researchers believe that a large comet or asteroid hit Earth and sent the rock up through the atmosphere and into space. The rock was able to make this serendipitous collision with the moon because it was three times closer to Earth at the time.

The rock contains quartz, feldspar and zircon, which are very common on Earth but not so much on the moon.

An analysis of the rock revealed that it formed at temperatures associated with Earth and in an Earth-like setting combined with oxygen. It crystallized between 4 billion and 4.1 billion years ago, when the Earth was young, about 12.4 miles below the surface.

The rock that was returned by Apollo 14 astronauts.

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