The 2020s have already seen many Moon landing attempts, although many have crashed or rolled over. With all the excitement surrounding the possibility of humans returning to the Moon, both commercial interests and scientists stand to gain.
The Moon is perfectly suited for researchers to build telescopes they cannot place on Earth; because the Moon does not have as much satellite interference or a magnetic field that blocks radio waves as the Earth. But only recently have astronomers like me begun to think about the potential conflicts between the desire to expand knowledge of the universe on the one hand, geopolitical rivalries and commercial gain on the other, and how to balance these interests.
As an astronomer and co-chair of the International Astronomical Union’s Lunar Astronomy working group, I am prepared to explore this question.
Everyone to the south pole
By 2035 (just 10 years or so away) American and Chinese rockets could carry humans to long-term moon bases.
Both bases are planned for the same small areas near the south pole due to the nearly constant solar energy available in this region and the rich supply of water that scientists believe may be found in the darkest nearby regions of the Moon.
Unlike the Earth, the Moon is not tilted relative to its path around the Sun. As a result, the Sun orbits the horizon near the poles and barely sets at some crater rims. There, the never-setting Sun casts long shadows over nearby craters, hiding their floors from direct sunlight for the last 4 billion years, or 90% of the solar system’s age.
These craters are basically pits of eternal darkness. And it’s not just dark there, it’s cold: below -418 degrees Fahrenheit (-250 degrees Celsius). The air is so cold that scientists predict that the ice-shaped water at the bottom of these craters, probably brought by ancient asteroids hitting the Moon’s surface, will not melt or evaporate for a very long time.
Research from lunar orbit suggests that these craters, called permanently shadowed areas, could hold half a billion tons of water.
Constant sunlight for solar energy and proximity to frozen water make the Moon’s poles attractive for human bases. The bases will also need water to feed hungry astronauts, drink, bathe, and grow crops. Bringing in long-term water supplies from the Earth is incredibly expensive, so a local watering hole is of great importance.
telescopes on the moon
For decades, astronomers had ignored the Moon as a potential location for telescopes because it was simply not possible to build telescopes there. But human bases create new opportunities.
The radio-shielded far side of the Moon, which we can never see from Earth, makes it possible to record very low-frequency radio waves. These signals are likely to contain signatures from the “Dark Ages” of the universe, a time before any stars or galaxies were formed.
Astronomers can also put gravitational wave detectors at the poles, because these detectors are extraordinarily sensitive and there are no earthquakes in the Moon’s polar regions to disturb them as they do on Earth.
A gravitational wave detector on the Moon could allow scientists to collect data from pairs of black holes orbiting very close together just before merging. Predicting where and when they will converge tells astronomers where and when to look for a flash of light they would otherwise miss. With these extra clues, scientists can learn how these black holes are born and how they evolve.
The cold at the lunar poles shifts the telescopes’ blackbody radiation to longer wavelengths, making infrared telescopes much more sensitive. These telescopes could provide astronomers with new tools to search for life on Earth-like planets beyond the solar system.
And more ideas keep coming. The first radio antennas are scheduled to land on the far side next year.
conflicting interests
But the rush to build a base on the Moon could interfere with the conditions that make the Moon so attractive for research. Although the Moon’s surface area is larger than Africa’s, human explorers and astronomers want to visit places within the same few kilometers.
However, activities that would help sustain human existence on the Moon, such as water mining, would create vibrations that could disrupt the gravitational wave telescope.
Additionally, many elements found on the Moon are extremely valuable on Earth. Liquid hydrogen and oxygen make up valuable rocket fuel, and helium-3 is a rare substance used to develop quantum computers.
But one of the few places on the Moon rich in helium-3 lies in one of the most likely locations for a dark age radio telescope to be placed on the far side.
Finally, there are at least two internet and GPS satellite constellations planned to orbit the Moon a few years from now. Unintentional radio emissions from these satellites could render the Dark Age telescope useless.
The time is now
But compromise is out of the question. There may be several alternative spots to locate each telescope.
In 2024, the International Astronomical Union convened the Lunar Astronomy working group to begin defining which regions astronomers want to preserve for their studies. This requires ranking the fields according to their importance to each type of telescope and starting a conversation with a key United Nations committee. These steps could help astronomers, astronauts from multiple countries, and special interest groups share the Moon.
This article is republished from The Conversation, an independent, nonprofit news organization providing facts and authoritative analysis to help you understand our complex world. Written by: Martin Elvis, Smithsonian Institution
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Martin Elvis is Co-Chair of the International Astronomical Union Working Group on Lunar Astronomy