Will future colonists really find ice at the lunar poles?

The entire planet was excited about the overall success of the Indian probe Chandrayaan 3. Some perhaps more than others because the probe and its rover are the first to explore one of the Moon’s poles on the ground, more precisely its south pole. To understand this we can remember his novel 2001: A Space OdysseyArthur Clark precisely locates a permanent United States lunar base in the crater key At the south pole of the Moon. This is no coincidence since we were already speculating in the 1960s on the possibility that frozen water, a remnant of an intense cometary bombardment billions of years ago, could be found beneath the poles. Some lunar craters have always remained in shadow and therefore well below 0°C for billions of years.

This was confirmed by lunar missions like Chandrayaan-1 or LCROSS (Lunar Crater Remote Observation and Sensing Satellite) and even at the level of absolutely key A few years ago though it was not in the moon’s shadow, as shown in the video below.

So of course, Arthur Clarke failed to predict the future of space conquest for the end of the 20th century.^I century 50 years ago, but aren’t his predictions on this subject simply wrong from a calendar point of view? After all, he has already correctly predicted an aspect of the modern world that is ours, as Futura recalled on March 12, 2019, on the occasion of the 30th anniversary of the Web’s birth at CERN.

A summary presentation of NASA’s discoveries in the crater key, To get a fairly accurate French translation, click on the white rectangle at the bottom right. The English subtitles should then appear. Then click on the nut to the right of the rectangle, then on “Subtitles” and finally on “Translate automatically”. Select “French”. NASA’s Ames Research Center

Craters with insolation changing over billions of years

However, research by Norbert Schorghofer Planetary Science Institute In Tucson, Arizona (United States), with his colleague Raluca Rufu Southwest Research Institute in Boulder, Colorado (United States), suggesting that potential ice deposits at the poles may be less significant than expected. The same thing comes to light from the work presented by him in an article published in a famous magazine. science advancement,

, These results change predictions about where we expect to find water ice on the Moon, and they also significantly change estimates of how much water ice exists on the Moon. Ancient reserves of water ice are no longer expected “, Schorghofer announced in a press release. Planetary Science Institute,

This has led researchers to revise the dates and duration of existence of permanent shadow zones (ZOPs) on the Moon. It now appears that the oldest appeared less than 3.4 billion years ago, i.e. when the cometary bombardment of the Earth–Moon system had already diminished considerably. So less water than expected should be found at the poles, but this of course remains to be verified on site.

To reach this conclusion, both researchers relied on recent work in celestial mechanics by a team of French astronomers, which allowed them to better take into account the effects of the Sun’s and Earth’s tidal forces, which affect not only the Moon’s Causes movement. away from Earth for billions of years, but the tilt of our satellite with respect to its orbital plane also changes, which precisely changes the insolation of the lunar poles.

Still in the PSI press release, Schorghofer explains: ” When I heard about their results, I immediately knew that they had profound implications for the discovery of water ice on the Moon. I dropped whatever I was doing and started working on the details with the help of my co-writer Raluca Rufu. We calculated the orientation of the lunar rotation axis and the extent of permanent shadow areas. We were able to quantify the actual youth of the lunar ZOP. The ZOPs have a maximum average age of 1.8 billion years. There are no ancient deposits of water ice on the Moon ,

Lunar colonization as a prelude to space exploration?

We know that some lunar craters still contain water, notably thanks to analysis of the plume produced by the Centaur module’s impact on the floor of Cabeus crater on October 9, 2009. Since this crater is less than a billion years old. , This is still very encouraging, as even the younger ZOPs contain ice and the oldest ones should have even more.

Let us hope that the Artemis mission will be the first step towards the realization of projects, first of lunar colonies and then of space colonies built from lunar soil and as a result of the work of Gerard Kitchen O’Neill (February 6, 1927 – ). April 27, 1992) who made an impact on the general public with a book on space colonies published in 1976 and whose English title is high marginal, We can learn about O’Neill’s vision of the future from another work available for free on the web from the early 1980s: 2081: An optimistic view of the human future,

Explanations that are not too technical, but with calculations, can be found in an article published by Gerard O’Neill in 1974. physics today, The construction of these colonies is actually based on materials extracted from lunar soil by the colonists.

As shown in this short video, materials for building space colonies are taken from the lunar colony, where gravity is weaker than on Earth. © Eric Wernquist