Chandrayaan-1 data indicates Earth’s electrons are forming water on the Moon

The magnetospehre plays an important role in protecting Earth from space weather and radiation from the Sun. The solar wind pushes this magnetosphere and reshapes it, making a long tail on the night side similar to what happens with comets. The plasma sheet in this tail region of the magnetosphere contains high-energy electrons and ions from the Earth and from solar wind.

The researchers built on previous work which showed that oxygen in the Earth’s “magnetotail” is rusting iron in the lunar polar region and decided to investigate changes in surface weathering as the Moon passed through the Earth’s magnetotail.

“This provides a natural laboratory for studying the formation processes of lunar surface water. When the Moon is outside of the magnetotail, the lunar surface is bombarded with solar wind. Inside the magnetotail, there are almost no solar wind protons and water formation was expected to drop to nearly zero,” said Shuai Li, lead researcher, in a press statement.

The researchers analysed remote sensing data that was collected by the Moon Mineralogy Mapper on the Chandrayaan-1 mission between 2008 and 2009. They mainly looked at the changes in water formation as the Moon passed through the Earth’s magnetotail.

Interestingly, water formation in the magnetotail seemed to be identical whether the Moon was in it or not. This could indicate that there are formation processes or sources of water that is not directly associated with solar wind protons.