There are no ancient deposits of water ice on the Moon

2023-09-14 13:46:17

MADRID, 14 Sep. (EUROPA PRESS) –

Most of the Moon’s permanent shadow areas arose less than 2.2 billion years ago and some of them caught ice in the recent pastreveals a new study.

“These findings change the prediction of where we would expect to find water ice on the Moon, and dramatically change estimates of how much water ice there is on the Moon. Ancient deposits of water ice are no longer expected,” he said it’s a statement first author Norbert Schorghofer, senior researcher at PSI (Planetary Science Institute).

Lunar water ice is an integral component of missions to the Moon, both to sustain human life and to produce fuel for spacecraft. Permanently shadowed regions (PSRs) are believed to have trapped ice and are a main focus of lunar exploration.

The Moon constantly migrates away from the Earth and feels tidal forces from both the Earth and the Sun. It has been known for decades that the Moon underwent a major reorientation of its rotational axis at some point in the distant past, but there was not enough data to really know when. Last year a group in France came up with a coherent story of the evolution of the Earth-Moon distance.

“When I heard about their result, I immediately realized that it had profound implications for the search for water ice on the Moon. I stopped everything I was doing and started working on the details, with the help of my co-author Raluca Rufu “said Schorghofer, whose study is published in Science Advances.

“We calculate the orientation of the lunar spin axis and the extent of the PSRs based on recent advances for the temporal evolution of the Earth-Moon distance,” he said. Early in its history, the Moon (which is 4.5 billion years old) was bombarded by comets and volcanism released water vapor from its interior, but only 3.4 billion years ago continuously shadowed areas began to appear. By then, these processes had begun to die out, so most of the water that reached the Moon or degassed from its interior could not have been trapped in the polar regions. Any ice that exists today in the polar regions must have a more recent origin.

THERE ARE NO ANCIENT WATER ICE DEPOSITS ON THE MOON

“We’ve been able to quantify how young the lunar PSRs really are,” Schorghofer said. “The average age of PSRs is 1.8 billion years, at most. “There are no ancient deposits of water ice on the Moon.”

The impact site of NASA’s LCROSS satellite, a robotic spacecraft that detected water in 2009, lies within a PSR that is less than a billion years old and thus all of the volatiles discovered there, which include water and carbon dioxide, they must be young, he said. In some ways this is very encouraging, because even young PSRs contain ice. Older PSRs should contain even more ice.

This work could also explain why the polar regions of the planet Mercury have much more ice than those of the Moon. Mercury’s PSRs are much older and could have captured water all along.