Water on the Moon: What does this mean for space travel? By Sarah Laptain

pH7 Science Blog
Nov 27, 2020
2 min read

NASA’s exciting discovery of water on the moon gives promise for a future moon base. Previously water has only been detected in cold, shaded places on the Moon, but it has now been found in sunlit parts of the lunar surface too. With this discovery, future missions to the moon can use the natural resources to sustain life.

In 1969, when Apollo astronauts went to the moon, it was thought to be completely dry. Then in 2008 data from India’s Chandrayaan-1 spacecraft indicated that there was water in the permanently dark craters around the Moon’s south pole. Since then, missions have confirmed evidence of the water at the poles. However, the sunlit parts of the Moon have temperatures exceeding the boiling point of water so it was assumed no water could be found there. With this new discovery, it will be much easier to access than venturing to the cold, dark poles.

How was the water found?

Two studies published in Nature confirm the presence of water across the Moon’s surface. NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) was where the first discovery was made from. SOFIA is a Boeing 747 flying above most of the Earth’s atmosphere giving a clear view of the Solar System. It has been equipped with instruments to collect data from space, including the 2.7-metre reflecting telescope and infrared camera used to make this discovery.

These instruments detected a signature signal specific to water molecules in the Moon’s sunny Clavius Crater. Before this, it had been assumed that these wouldn’t survive the high daytime temperatures on the Moon. It has been suggested that they were protected from evaporating by being stored in voids between grains or within glass in the Moon’s surface.

In the second study mini-craters across the lunar surface were analysed to determine if they were cold enough for ice to form. Using NASA’s Lunar Reconnaissance Orbiter, they estimate that 40,000 square kilometres of the Moon’s surface can trap water. This will need to be examined further to confirm if these potential areas actually do hold trapped water.

Although this is all promising, the water may be difficult to extract and only small amounts of water was detected by the first study – the Sahara desert has 100 times the amount of water than SOFIA detected.

What does this mean for future missions?

NASA’s Artemis program is set to send humans back to the moon in 2024 and potentially establish some sort of lunar base there by the end of the decade. The abundance of water across the surface of the Moon means astronauts won’t have to brave the freezing temperatures of the poles for a base to be set up near water ice.

Once we know how this water can be extracted, it can be purified and used for drinking or for plants. Another option is to split it into hydrogen and oxygen and use it as fuel for space vehicles. If fuel can be accessed on the Moon, then less rocket fuel needs to be transported from Earth. This gives the option of using the Moon as a refuelling station for further space travel and make space exploration cheaper.

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