Astronomers have seen the first firm evidence that there are deposits of icy water on the surface of the moon – and they may have been laying there for the past 3 billion years.

The ice is nestled within craters at both poles of the moon that are permanently in shadow and bitterly cold at −163 °C. The presence of accessible water on the surface of the moon could prove useful if we ever establish a permanent base there.

Ultraviolet scans in 2008 and 2009 using spectrometers aboard India’s first lunar orbiter, Chandrayaan-1 , had hinted the …