Last month, a NASA spacecraft and its accompanying spent rocket stage slammed into the surface of the Moon's south pole, in the Cabeus crater. A few weeks later, as everyone was teeming with anticipation, the much-awaited announcement finally came – water existed on the Earth's satellite. Spectrograph readings confirmed the presence of more than 100 kilograms of water in the debris plume caused by the impacts, so the issue was settled. Now, the debate is raging on as to the source of the water. Some say the Moon develops it thanks to its interactions with the Sun, while others claim the stuff may have been brought by comets, as seen before on Mars, NewScientist reports.

Evidence from the LCROSS team at NASA seems to support the latter variant, representatives have recently shared. The Lunar Crater Observation and Sensing Satellite first dropped its Centaurus rocket stage towards the surface of the satellite, and then followed it into the plunge shortly, snapping pictures as it went downhill. It flew right through the massive debris plume the rocket stage threw up, although it was intentionally crashed a few miles away from the former's impact spot.

The data that were collected during these maneuvers were discussed and analyzed recently, at the Lunar Exploration Analysis Group meeting, held this week in Houston, Texas. The gathering saw more than 160 lunar experts come together and discuss aspects related to the possible water-forming processes that might have taken place on the Moon, or elsewhere.

The meeting concluded that it made a lot more sense, based on the pieces of evidence and the precedents, that the water on the Moon at the moment had not been formed there, in those large amounts. Most likely, both considered processes are at work, but the latter is more viable in terms of producing such large quantities of water-ice.

The discovery also yields some important results for the American space agency, which plans to return to the natural satellite in the 2020s, and then set up a permanent scientific colony there. All that explorers need, as in fuel, air and water, can now be produced directly from water-ice, under the condition that efficient methods of extracting it are devised. Some rovers have already been produced for this job, but their resilience has not yet been fully tested.