The most accepted hypothesis for the formation of the moon involves a giant collision between the Earth and another Mars-sized planetary body about 4.5 billion years ago. The debris that resulted from this impact coalesced into the moon. While this sounded like the most reasonable scenario and there were many clues suggesting an impact, we’ve never been able to detect any evidence of that other planetary body on the moon. Now, three lunar samples that were returned in the Apollo missions have now revealed traces of material that is believed to have come from that other planetary body, known as Theia. The results of the study were published in Science.

read more Lunar Samples Support Giant Impact Theory | IFLScience.