Sun may make most of the water on moon’s surface

astronaut on the moon

A closer look at moon rocks from the Apollo missions suggests that particles from the sun, not meteorite impacts, are responsible for giving the lunar surface most of its water.


Bombardement by particles from the sun — not comets and meteorites — may be the main source of water locked with the moon’s rocks.

Lunar soil may hold, on average, only 15 percent of the hydrogen that comets and meteorites delivered billions of years ago, researchers report October 6 in the Proceedings of the National Academy of Sciences. Protons from the solar wind that combine with oxygen on the lunar surface may generate the rest of the water, the scientists suggest.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

More Stories from Science News on Planetary Science