Loose rubble in permanent shadow at the Moon’s south pole contains a hotchpotch of volatile materials, including hydrogen, mercury, silver, hydrocarbons – and substantial quantities of water ice.
The findings come from the first published results of NASA’s LCROSS (Lunar Crater Observation and Sensing Satellite) experiment, which last October hurled a spent rocket into a portion of a crater where temperatures are so cold — about –230ºC — that water vapour from ancient comet or asteroid impacts would freeze permanently.
The glowing dot in the centre of this swathe of colour shows that the impact generated temperatures above 700°C. The data was recorded by the Lunar Reconnaissance Orbiter.
Although it did not produce as spectacular a blast as anticipated (see ‘Moon smash gives off flash’), the impact created a crater 25–30 metres wide, and lofted a few tonnes of dust and vapour about a kilometre above the surface. That was analysed by LCROSS’s trailing observation satellite, which watched the site for 4 minutes before it too crashed into the Moon, and by NASA’s Lunar Reconnaissance Orbiter (LRO),which passed within 80 kilometres of the impact.
Read more here Astronomers comb through Moon smash haul : Nature News.