Given plans for future manned missions to the Moon — and interest in the potential for longer-term lunar habitation — the presence of water on the Moon is of critical importance. Studies over the last few decades have revealed water lurking on our satellite in numerous forms. But how does it get there?
Water In, Water Out
Overview of the lunar OH/H2 abundance in the polar regions of the Moon, as derived from M3 observations in January/February 2009. [Adapted from Wang et al. 2021]Lunar water has been found locked in ice form in the cold, permanently shadowed craters at the Moon’s poles, and drifting in gas form in the very thin lunar atmosphere. In addition, we’ve discovered that water exists in trace amounts across the Moon’s surface, bound to lunar minerals.
But lunar water is more complicated than its mere presence or absence. The Moon is also thought to have a water cycle — water is continuously created on or delivered to the Moon’s surface, and then destroyed on or removed from it.
Understanding the driving processes in this cycle will enable us to best leverage the Moon’s resources and deepen our insight into the physics that influences airless rocky ...