by Astronomers are calling for urgent protection of sites on the moon rated as the best spots in the solar system for advanced instruments designed to reveal the secrets of the universe.
The main sites are free from ground vibrations, shielded from noisy Earth broadcast signals or very cold – making them particularly suitable for sensitive equipment that may make observations from other locations impossible.
But the pristine spots, known as sites of extraordinary scientific importance (Sesis), are at risk of being destroyed by a wave of imminent missions such as lunar navigation and communication satellites, rovers and mining operations, with experts warning on Monday that protection of the precious. The sites were “urgent matter”.
“This is the first time humanity has decided how we will expand into the solar system,” said Dr. Martin Elvis, an astronomer at the Harvard and Smithsonian Center for Astrophysics in Massachusetts. “We risk missing one-of-a-kind opportunities to understand the world.”
At least 22 international missions are expected to touch down on the moon by the end of 2026, with half going to sites near the lunar south pole. More will follow, including commercial and civilian landings, and two lunar bases, one US, the other Chinese and Russian, are expected to be operational by the 2030s.
With no coordinating authority, there is nothing to prevent future fights on the moon, the researchers say. Risks include physical collisions and dust clouds kicked up by lunar activity to vibrations, electromagnetic interference and damage to sites due to drilling and other operations.
Astronomy from the moon was unlikely two decades ago, but researchers now have firm plans for instruments, some of which could be installed on the moon’s surface by the end of the decade. They include optical, infrared, X-ray and radio telescopes, particle detectors to investigate the solar wind and cosmic rays, and gravitational detectors to detect the subtle twangs in space-time when black holes and neutron stars collide.
The edge of the moon is the radio quietest place in the solar system, thanks to the 70bn tonnes of lunar rock that blocks transmissions from Earth. The conditions allow radio telescopes to look into the cosmic dark ages, the time before the stars, and to search for “technological signatures” of alien life. But the far 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 the US startup is trying to mine for quantum computing and fusion energy industries.
Other key locations are crater bases at the north and south poles of the moon that have been shielded from direct sunlight for billions of years. These permanently shadowed regions, or “cold traps”, are among the coldest places in the universe and are ideal for large infrared telescopes that can only operate at temperatures below -200C. Infrared lunar telescopes could image Earth-sized planets around distant stars and look for signs of life in their atmospheres.
Additional spots the astronomers want to protect are cold traps in seismically quiet regions of the moon. The lack of ground vibrations makes these suitable for gravitational wave detectors which can detect movements 1,000 times smaller than an atomic nucleus. One idea is to place seismometers in cold traps around the moon to detect how the moon itself shakes when gravitational waves pass through it.
Writing in the Philosophical Transactions of the Royal Society, Elvis and Dr Alanna Krolikowski, a political scientist at the Missouri University of Science and Technology, said Sesis presented “extraordinary opportunities for astronomical research” but warned that the sites are “rare and fragile”.
Some cold traps, for example, contain ice and are near “peaks of eternal light” – crater rims and ridges that receive sunlight all year round – making them prime locations for experiments, lunar bases and mining operations that require power, water and oxygen. “The prospect of competing uses for the same piece of land is quite large,” Elvis said.
Constellations of satellites that provide communications and GPS on the moon could ruin astronomers’ plans by interfering with telescopes, and heavy rovers and mining robots could generate dust and vibrations that scupper sensitive experiments, the researchers add.
“We were all surprised when the Starlink satellites became so visible,” Elvis said, referring to the impact Elon Musk’s megastars have on the night sky. “We have to put our ducks on a par and be able to argue for the protection of specific places on the moon.”
