Scientists find proof of ice on the moon

There is almost certainly ice water on the surface of the moon, hiding in the cold, dark places near the north and south poles, a new study shows.

Scientists had already thought there was water up there, but now we have some of the most definitive proof to date. It appears that this ice — very muddy ice, mixed with a lot of lunar dust — exists inside craters where direct sunlight does not reach it.

But we still do not know how deep it goes, or how exactly it got there.

The authors of the study, published Monday in Proceedings of the National Academy of Sciences, say the findings are exciting because they call for further exploration of our rocky satellite. The ice could even be a resource for human visitors — perhaps to be used for drinking water, or even to make rocket fuel.

Shuai Li, the lead author and a planetary scientist at the University of Hawaii at Manoa, said that despite decades of lunar research, scientists have had trouble exploring the polar regions, in part because the craters are so dark.

“So there aren’t too many measurements,” he said. “But a lot of things are going on there.”

Researchers estimate exposed ice covers only 3.5 per cent of the craters’ shadowy areas. They don’t know whether the water runs deep, like the tips of buried icebergs, or is as thin as a layer of frost.

Li hopes to see more lunar exploration in the near future. In fact, this new evidence of ice could make such exploration more likely. After all, scientists still have questions about how deep this water goes, whether it could be useful to human visitors, and where it came from — was it delivered by comets and asteroids? And if so, when?

The use of near-infrared light could help scientists find new answers to those questions.