Water has been definitively found on the Moon, Nasa has said, and there are a set of “water traps” that could hold it stably.
The research suggests that water could be distributed right across the lunar surface, not just trapped in the cold, shadowed parts of the Moon.
The discovery is a major breakthrough in the mission to explore the rest of the solar system, as well as giving a better understanding of the lunar surface.
It also raises new questions about how exactly the water got there, and how it is able to survive the harsh conditions on the Moon.
It could, for instance, be trapped in “glass beads” on the surface that form when micrometeorites crash into the Moon and melt a part of the lunar surface, either forming water or capturing it in the beads as it does.
Scientists had previously thought that any water on the sunlit side of the Moon would immediately be lost. But it appears that it is in fact present, and not just on the parts that are shaded from the sun.
Nasa was keen to stress that the amount of water is very limited, with the new discovery representing only around one per cent of the amount of water found in the Sahara desert. But even that very small amount of water was not previously confirmed to exist, and it remains unclear how it could be created or stay on the surface.
Researchers had previously found evidence of hydration on the lunar surface. But it was unclear whether that hydrogen was in the form of hydroxyl – the chemical that makes up drain cleaners – or in the form of H2O, or water.