Electrons from Earth could form water on the Moon

Nature Astronomy: Electrons from Earth form water molecules on the Moon

A team of scientists led by a planetary scientist from the University of Hawaii at Manoa has discovered a new mechanism for the formation of water molecules on the Moon. Researchers have found that high-energy electrons found in the Earth’s plasma layer play a role in the weathering process on the lunar surface, contributing to the formation of water in the regolith. The results of this study were published in the journal Nature Astronomy.

The Earth is surrounded by a magnetosphere, which is a region of plasma whose behavior is determined by the magnetic field and solar wind. The magnetosphere has a long tail directed away from the Sun and filled with high-energy ions. As the Moon crosses this tail, oxygen ions are known to attack iron in the moon’s polar regions, causing it to oxidize.

In the new study, scientists analyzed data collected by the lunar Mineralogy Mapper instrument aboard India’s Chandrayaan 1 mission between 2008 and 2009. They studied changes in the rate of formation of water molecules in the regolith as the Moon passed through the Earth’s magnetotail.

When the Moon is outside the magnetotail, the moon’s surface is bombarded by high-energy protons from the solar wind, which promotes the formation of water. It was assumed that the formation of water completely stops when the Moon is in the magnetosphere, but in fact this is not the case. According to scientists, high-energy electrons have the same effect on regolith as protons from sunlight.