Moon Settlers Could Have Access to Water

by Monica Joshi

Before we went to the moon, we looked at it in awe. After we went to the moon, we thought about how to inhabit it. Now, we are quite adamantly looking for ways to survive on it. According to new calculations, future lunar colonists need to worry about one less thing: their water supply.

As sunlight hits the surface of the moon, frozen water molecules from the surface warm up and evaporate. The water vapour then cools and condenses into a frost. It is this frost that could lead to a steady supply of drinking water. The problem, up till now, was that this water was either buried beneath the surface or located in the moon's cold, dark craters.

NASA scientist, Tim Livengood, and his colleagues are suggesting that there are simpler ways to harvest moon's water; simply set up solar distilleries, which are clear plastic domes that can be placed over parts of the lunar surface to capture water vapour and provide a solid surface for it to condense on.

Using hydrogen measurements taken between 2009 and 2011 by NASA's Lunar Reconnaissance Orbiter (LRO), Livengood calculated that the frost build-up at the terminator would be just under a fifth of a millimetre thick. This is enough to yield about 190 millilitres of water per square metre per lunar day, with a suitable set-up. This set-up could include a small sun-tracking shade to cast a permanent shadow, mimicking the terminator and allowing astronauts to collect frost all day long.

After it freezes, astronauts could scrape off the frost and melt it for drinking water. Livengood’s team used data from NASA’s Lunar Reconnaissance Orbiter (LRO) to calculate that, in some places, a dome covering one square meter of lunar regolith could produce 190 milliliters of water per day. (That’s about 6.5 fluid ounces, or approximately half a can of soda.)

But Andrew Jordan of the University of New Hampshire in Durham thinks water isn't the only possible explanation for the hydrogen peaks that LRO observed in some regions.

"I would expect the amount of hydrogen to increase with depth."

He adds that since the LRO observations are in line with hydrogen decreasing with depth, he is inclined to think something else is going on. It could be that hydrogen is leaking from localised sources. 

Livengood is optimistic about what he has found, even though he acknowledges the possibility that he could be misinterpreting the LRO data:

"There is something going on here that was unanticipated, which means there is something new for us to learn about the world.”

He is confident that at the very least there is plenty of hydrogen at the surface, where previously scientists thought there was none. It’s a lot less than lunar settlers could dig up at the poles, Livengood told New Scientist, but it doesn’t take any back-breaking labor to get to it.

"The quantity of water is much less than what we could dig up at the lunar poles, but we get it with very little energy investment on our part.”

Based on these new findings, it seems like Astronaut Ron Garan's compelling case to set up a base on the moon is not such a far off feat.