Until recently the moon was thought to be bone dry. But measurements in the last year from the Mini-SAR and Moon Mineralogy Mapper (M3 or “M-cubed”) instruments on India’s Chandrayaan-1 moon probe and from NASA’s recent LCROSS mission have proved that wrong.
Mini-SAR found 40 craters, each containing frozen water at least 6.6 feet (2 meters) deep on the lunar surface – which adds up to 600 million tons of lunar ice stuff altogether. LCROSS slammed into the moon on Oct. 9, 2009 and found evidence of water in another crater.
So far the tally includes sulfur dioxide (SO2), methanol (CH3OH), and the curious organic molecule diacetylene (H2C4).
The researchers don’t yet know why some craters contain loads of pure ice while others are dominated by an ice-soil mixture. It’s probably a sign that the moon water comes from more than one source.