A research team has discovered another piece in the puzzle of the formation of the Moon and water on Earth. The prevailing theory was that the Moon was the result of a collision between the early Earth and the protoplanet Theia. New measurements indicate that the Moon formed from material ejected from the Earth's mantle with little contribution from Theia. In addition, the findings support the idea that water could have reached the Earth early in its development and may not have been added by late impacts.