The far side of the Moon is a dark and quiet spot which makes it the ideal location to pick up faint, very low-frequency radio waves.
Scientists are gearing up to use telescopes on the dark side of the Moon that could help detect signs of alien life if it is really out there. Astronomers have long fantasized about locating observatories on the lunar surface, but the idea has come back into the spotlight as humans gear up for another Moon mission. Different space organisations, including NASA, the European Space Agency (ESA), and the National Astronomical Observatory of China, plan to instal radio telescopes.
This is a dark and quiet spot that marks the ideal location to pick up faint, very low-frequency radio waves, which are remnants from the universe’s Dark Ages. This is because, in this spot, they are protected from Earth’s radio chatter (transmissions). Experts say these conditions offer up the potential to find something “extraordinary”.
James Carpenter, from the ESA’s Human and Robotic Exploration Programme, said at the Royal Society’s Astronomy from the Moon conference this week: “This is something that has been around for a long time as an idea.
“For the first time agencies are starting to take this very seriously. It’s becoming something that is seen as credible and important and something that might actually happen. We could do some extraordinary science.”
This comes after NASA’s successful Artemis launch, which paved the way for mankind’s return to the Moon by the end of the decade.
According to Prof Joseph Silk, of the Institut Astrophysique de Paris, a 60-mile wide antenna array on the far side of the Moon certainly would help detect the faint radio signals left over from the dawn of the universe.
He told the Telegraph: “There has been an immense amount of interest in doing projects on the Moon and for cosmology it may allow us to reach some of the ultimate limits that we dream about.
“The Moon is the most radio-quiet sky in the inner solar system, and there you could look for the ripples from these clouds.”
Back in 2021, NASA announced a proposal for the Lunar Crater Radio Telescope, an ultra-long-wavelength radio telescope on the far-side of the Moon. NASA said it would be far more effective at finding out about the universe’s Dark Ages than Earth-based or Earth-orbiting telescopes. The Dark Ages of the universe refers the period in its early history after the Big Bang but before the first stars.
The team behind the planned telescope is set to deploy space robots to build a half-mile-wide (one kilometre-wide) radio telescope in one of several proposed craters on the far side of the surface. The telescope itself will have a wire mesh that will need to be capable of withstanding temperature ranges of between -173 degrees (Celsius) to 127 degrees.
Saptarshi Bandyopadhyay, leader of the Lunar Crater Radio Telescope research team, said: “There’s a whole region of the universe that we simply cannot see.
“The development of this concept could produce some significant breakthroughs along the way, particularly for deployment technologies and the use of robots to build gigantic structures off Earth. I’m proud to be working with this diverse team of experts who inspire the world to think of big ideas that can make groundbreaking discoveries about the universe we live in.”
But not only could the radio telescopes help offer clues to the origins of the universe, but so too do they offer the potential to search for extraterrestrial life.
That’s because, if it really is out there, the telescopes may be able to detect regular and continuous pulses of energy from outside of the universe which could indicate alien technology.
Using radio telescope on the Moon’s dark side offers an advantage in this respect because radio signals are frequently constrained by interference from signals on Earth.