Whether or not water in the form of ice exists on the Moon is a hotly debated issue. In fact, India’s Chandrayaan-1 spacecraft, which was launched on Wednesday, is carrying a U.S.-built radar that is specifically intended to look for water-ice at the lunar poles.
Meanwhile, a paper from a team of Japanese scientists that is coming out this week is bound to fuel the controversy further. Based on images from a camera on Japan’s Kaguya lunar probe that was launched last year, their findings question whether such ice does indeed exist.
On the Moon’s surface, any water would be rapidly vapourised by the heat of the Sun’s rays and lost to space. But since the early 1960s, it has been argued that some water might have been transported to the polar regions. There, over millions of years, the water could have accumulated as ice at the bottom of craters that are permanently in shadow. Indeed, two U.S. spacecraft that went to the Moon in the 1990s found indications of water-ice in the permanently shadowed areas at the poles.