Astronomers are calling for the urgent protection of sites on the moon that have been designated as the best places in the solar system for advanced instruments designed to reveal the secrets of the universe.
The prime locations are free from ground vibration, shielded from Earth’s noisy broadcast signals or deep cold – making them uniquely suited for sensitive equipment that can make observations from elsewhere impossible.
But the pristine sites, known as Sites of Outstanding Scientific Interest (SSIS), are at risk of being ravaged by a looming wave of missions such as lunar navigation and communications satellites, rovers and mining operations, with experts warning on Monday that safeguarding the precious sites was an “urgent matter”.
“This is the first time humanity has to decide how we will expand in the solar system,” said Dr. Martin Elvis, an astronomer at Harvard and the Smithsonian Center for Astrophysics in Massachusetts. “We are in danger of losing unique opportunities to understand the universe.”
At least 22 international missions are expected to land on the moon by late 2026, with half heading to sites near the lunar south pole. More will follow, including commercial and civilian landings, while two lunar bases, one US, the other Chinese and Russian, are expected to be operational in the 2030s.
Without any coordinating authority, there is nothing to prevent future collisions on the moon, the researchers say. The risks range from physical collisions and dust clouds kicked up by lunar activity to vibrations, electromagnetic interference and damage to sites from drilling and other operations.
The prospect of conducting astronomy from the moon was little more than a dream two decades ago, but researchers now have firm plans for instruments, some of which could be installed on the lunar surface by the end of the decade. These include optical, infrared, X-ray, and radio telescopes, particle detectors to probe the solar wind and cosmic rays, and gravitational wave detectors to observe the subtle ripples in space-time when black holes and neutron stars collide.
The far side of the moon is the quietest place in the solar system, thanks to the 70 billion tons of lunar rock that blocks transmissions from Earth. The conditions make it perfect for radio telescopes to observe the cosmic dark ages, the time before stars, and to search for “technosignatures” of alien life. But the other side is so mountainous, scientists have identified only three sites where large telescope arrays could be installed. One, called Mare Moscoviense, is rich in helium-3, a substance that US startup Interlune wants to mine for quantum computation and fusion energy industries.
Other prime locations are crater bases at the north and south lunar poles that have been shielded from direct sunlight for billions of years. These permanent shadow regions, or “cold traps”, are some of the coldest places in the universe and ideal for large infrared telescopes that can only operate at temperatures below -200C. Lunar infrared telescopes can image Earth-sized planets around distant stars and search for signs of life in their atmospheres.
Further places the astronomers want to protect are cold traps in seismically quiet regions on the moon. The lack of ground vibrations makes it ideal for gravitational wave detectors that can detect motions 1,000 times smaller than an atomic nucleus. One idea is to place seismometers in cold traps around the moon to determine how the moon itself shakes when gravitational waves pass through it.
Write in the Royal Society’s Philosophical TransactionsElvis and Dr Alanna Krolikowski, a political scientist at the Missouri University of Science and Technology, said Sesis offered “extraordinary opportunities for astronomical research”, but warned that the sites were “scarce and fragile”.
For example, some cold traps contain ice and are located along “peaks of eternal light” – crater rims and ridges that receive sunlight year-round – making them prime locations for experiments, lunar bases and mining operations that require power, water and oxygen. “The prospect of having competing uses for the same piece of land is pretty big,” Elvis said.
Constellations of satellites that provide communications and GPS on the moon can also destroy astronomers’ plans by interfering with telescopes, while heavy rovers and mining robots can raise dust and vibrations that hinder sensitive experiments, the researchers add.
“We were all surprised with the Starlink satellites becoming so visible,” Elvis said, referring to the impact of Elon Musk. mega constellations in the night sky. “We have to get our ducks in a row and be able to argue that specific places on the moon should be protected.”
