Moon Water Mystery

A new NASA study of Apollo lunar soils reveals the Moon's record of meteorite impacts and timing of water delivery, placing upper bounds on how much water meteorites could have supplied to Earth.

Researchers used a novel method for analyzing lunar regolith, finding that even under generous assumptions, meteorite delivery since about four billion years ago could only have supplied a small fraction of Earth's water.

The study has implications for our understanding of water sources on Earth and the Moon, suggesting that late delivery of water-rich meteorites was not the dominant source of Earth's oceans.