It is still unclear whether the hydrogen represents the release of water by the heat of the impact, or whether it simply sheds light on the way that water is formed on the Moon from its chemical constituents.

BBC: Nasa reveals new information about moon probes crash sites

Tide: periodic rising and falling of large bodies of water resulting from the gravitational attraction of the moon and sun acting on the rotating earth.

UNESCO: L O S S A R Y

Crops need a sheltered environment, protected from the extreme temperatures and frightening levels of radiation found on the moon's surface, with water, carbon dioxide and light.

CNN: To boldly grow where no one has grown before