by The 2020s have already seen many moon landing attempts, although many have crashed or failed. With all the excitement surrounding the prospect of humans returning to the Moon, both commercial and scientific interests can thrive.
The Moon is ideal for researchers to build telescopes that they can’t put on Earth because it doesn’t have as much satellite interference as Earth does, or a magnetic field that blocks radio waves. But recently astronomers like me have started to think about possible conflicts between the desire to expand knowledge of the universe on the one hand and geopolitical rivalries and commercial gain on the other, and how to balance those interests.
As an astronomer and co-chair of the International Astronomical Union’s working group, Astronomy from the Moon, I am comfortable exploring 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 lunar bases.
Both bases are planned for the same small areas near the south pole because of the almost constant solar power available in this region and the rich source of water that scientists believe could be found in the darkest regions of the nearby Moon.
Unlike the Earth, the Moon is not tilted relative to its path around the Sun. As a result, the Sun circles the sky near the poles, almost never laying on some edge of a crater. Then, the waning Sun casts long shadows over nearby craters, hiding their floors from direct sunlight for the past 4 billion years, 90% of the age of the solar system.
These craters are essentially pits of eternal darkness. And it’s not only dark down there, it’s also cold: below -418 degrees Fahrenheit (-250 degrees Celsius). It is so cold that scientists predict that water will not melt or evaporate in the form of ice at the bottom of these craters – formed by ancient asteroids colliding with the surface of the Moon for a long time.
Surveys from lunar orbit suggest that these craters, known as permanent shadow regions, could hold half a billion tons of water.
The constant sunlight for solar power and its proximity to frozen water make the poles of the Moon attractive to human bases. The bases will also need water for drinking, washing and growing crops to feed hungry astronauts. Bringing long-term water supplies from Earth is hopelessly expensive, so local borehole irrigation is a big deal.
Telescope on the Moon
For years, astronomers had ignored the Moon as a potential site for telescopes because it was simply impossible to build them there. But human bases open up new opportunities.
Because the far side of the Moon is in radio shadows, the part we never see from Earth, very low frequency radio waves can be recorded. These signs are likely signatures of the universe’s “Dark Ages,” a time before any stars or galaxies formed.
Astronomers could also place gravitational wave detectors at the poles, since these detectors are extremely sensitive, and the polar regions of the Moon do not have earthquakes to disturb them as they do on Earth .
A lunar gravitational wave detector could allow scientists to collect data from black hole pairs orbiting each other very closely before they merge. Astronomers tell where and when they will merge to predict where and when they should look for a flash of light they might miss. With those additional clues, scientists could learn how these black holes are born and how they evolve.
The coldness at the lunar poles also makes infrared telescopes much more sensitive by shifting the telescopes’ blackbody radiation to longer wavelengths. These telescopes could give astronomers new tools to look for life on Earth-like planets outside the solar system.
And more ideas keep coming. It is planned that the first radio antennas will land on the far side next year.
Conflicting interests
But the rush to build bases on the Moon could disrupt the conditions that make the Moon so attractive for research in the first place. Although the surface area of the Moon is larger than the area of Africa, human explorers and astronomers are trying to visit the same sites by a few kilometers.
But activities that help maintain a human presence on the Moon, such as water mining, will create vibrations that could destroy a gravitational telescope.
Also, many elements found on the Moon are extremely valuable back on Earth. Liquid hydrogen and oxygen make valuable rocket propellants, and helium-3 is a rare substance used to improve quantum computers.
But one of the few places rich in helium-3 on the Moon can be found in one of the most likely places to place a radio telescope in the distant Dark Ages.
Finally, at least two constellations of internet and GPS satellites have been planned to orbit the Moon for a few years now. Unintended radio emissions from these satellites could render the Dark Age telescope useless.
The time is now
But compromise is not out of the question. There may be several alternative spots to place each telescope.
In 2024, the International Astronomical Union convened the Astronomy from the Moon working group to begin defining the sites that astronomers would like to preserve for their work. This involves ranking the sites according to their importance for each type of telescope and starting to talk to a key UN committee. These steps can help astronomers, astronauts from multiple countries and private interests share the Moon.
This article is republished from The Conversation, a non-profit, independent news organization that brings you facts and analysis to help you make sense of our complex world.
Written by: Martin Elvis, Smithsonian Institution.
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Martin Elvis is Co-Chair of the International Astronomical Union’s Working Group on Astronomy from the Moon
