A groundbreaking study utilizing data from the Chandrayaan-1 mission has unveiled a compelling link between Earth’s electrons and the formation of water on the Moon. Scientists have harnessed this data to shed light on the origin of water ice detected in the Moon’s permanently shaded regions, and their findings could revolutionize our understanding of lunar water sources.
Published in the journal Nature Astronomy, the study posits that high-energy electrons within Earth’s plasma sheet may play a pivotal role in lunar weathering processes and could have catalyzed the creation of water on the Moon. The plasma sheet, a region characterized by trapped charged particles within Earth’s magnetosphere (the space controlled by Earth’s magnetic field), is central to this phenomenon.
Earth’s magnetosphere serves a critical function in safeguarding our planet from space weather and the Sun’s radiation. The solar wind continually interacts with and reshapes the magnetosphere, forming a lengthy tail on the night side, akin to the processes observed in comets. Within this tail region of the magnetosphere lies the plasma sheet, teeming with high-energy electrons and ions originating from Earth and the solar wind.
The research builds upon prior studies that unveiled the oxidation of iron in the lunar polar region due to oxygen from Earth’s “magnetotail.” Intrigued by these findings, the scientists sought to investigate surface weathering variations as the Moon traversed through 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,” explained Shuai Li, the lead researcher, in a press statement.
To explore this phenomenon, the researchers analyzed remote sensing data collected by the Moon Mineralogy Mapper during the Chandrayaan-1 mission, conducted between 2008 and 2009. Their focus was primarily on discerning alterations in water formation as the Moon encountered Earth’s magnetotail.
Remarkably, the study revealed that water formation within the magnetotail remained consistent regardless of whether the Moon was within its influence or not. This intriguing discovery suggests the existence of water formation processes or sources that are not directly linked to solar wind protons, potentially revolutionizing our comprehension of lunar water origins.