With NASA gearing up for a possible return to the Moon as soon as 2024 (and other countries not far behind), scientists are ramping up efforts to find the best ways to make best use of a permanent or long-term Moon base.
High on the list, of course, is collecting Moon rocks, especially in areas far from the six Apollo landing sites. One of these is near the rim of Shackleton Crater, which has been selected as the leading candidate for NASA’s upcoming Artemis Moon-landing program, says Jahnavi Shah, a graduate student at the University of Western Ontario, London, Canada.
The 21-kilometre-wide crater, whose rim nearly touches the lunar South Pole, is of interest for a number of reasons, Shah said last week at a virtual meeting of the international Committee on Space Research.
One is that its high rim is an extremely good place to get reliable solar power. Another is that craters in that region have permanently shadowed depths believed to host “cold traps” that retain water and other volatiles that may be of use to the fledgling base.
But there are also some particularly interesting rocks, Shah says, many within walking or rover range of potential landing sites. These, she says, could not only supply clues to how the lunar crust formed, but to how the Moon’s interior differentiated. They could also provide clues to the formation of the 2,500-kilometre-wide South-Pole Aitkin Basin, the Moon’s oldest and largest impact structure, and one of the dominant features of its far side.
But these aren’t the only type of rocks researchers at a lunar base could study. Astronaut-scientists could also to drill beneath the surface to find layers of rocks that have been buried for varying lengths of time, says Ian Crawford, a planetary scientist at Birkbeck College, UK.
By studying how these rocks were influenced by space radiation when they were on the surface, he says, it could be possible to trace the history not only of the solar wind, which would have smashed into them when they were on the surface, but to trace the varying levels of extrasolar cosmic rays to which they were exposed.
By collecting rocks from many such layers, from many different dates in the past, he says, scientists could trace the history of these processes for billions of years, charting the evolution both of the Sun and of our galactic neighborhood.
“It would be a lot of work,” Crawford says, but that’s why it is particularly appealing for a Moon base. “It’s the kind of thing that would require a large science structure on the Moon.”
Other proposals have nothing to do with rocks.
Jean-Pierre De Vera of the German Aerospace Center, Berlin, for example, notes that it’s possible to send “micro-greenhouse” cubes to the Moon, looking to see how plants and microbes grow under lunar conditions—and by extension, under less-harsh Martian conditions. That would be useful not only for refining the search for extraterrestrial life, but for testing plant-based life-support systems for future, larger colonies.
Other scientists note that a Moon base is an extremely good platform for studying both the Earth and the Sun.
In the case of the Earth, says Shaopeng Huang of Shenzhen University, China, the goal would be to study the Earth’s energy budget by measuring how much sunlight it reflects and how much heat energy it emits in the form of infrared radiation.
By doing this, Huang says, we can leverage a Moon base to further our understanding not of the Moon, but of ourselves, particularly in regard to climate change. “A lunar outpost will allow global-scale records of the Earth’s energy budget, which is critical to our understanding of the working of the climate system,” he says.
At the same time, Georgia de Nolfo, of NASA’s Goddard Space Flight Center, Maryland, US, notes that a Moon base provides an extremely good platform for studies of neutron emissions from the Sun, from well outside the sheltering effects of the Earth’s magnetic field. These, she says, can help us understand the processes powering solar flares.
It would be possible to do this by sending instruments close to the Sun, de Nolfo says, but the type of instruments needed are large and heavy, and the Moon is closer and easier to reach.
Not to mention that, if things go according to NASA’s plan, we are going to be back there very, very soon.
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