Astronomers call for radio silence on the far side of the moon

There is a growing and passionate call for radio silence to be maintained on the far side of the moon.

A first-of-its-kind international symposium is being held this week, turning up the volume to consider the prospect of protecting property on the far side of the moon solely for specific scientific purposes. Despite the moon being surrounded by a vacuum, the meeting exudes an urgent atmosphere.

Under the auspices of the International Academy of Astronautics (IAA), the first IAA Moon Farside Protection Symposium will take place from March 21 to 22 in Turin, Italy. The aim of the meeting is to provide a wake-up call that prompts the global scientific, political and industrial community to become aware of a growing list of concerns.

Related: The moon could be perfect for advanced telescopes, but not if we don’t protect it

Electromagnetic pollution

Earth’s neighboring celestial body has the unique property of naturally shielding radio waves generated by chatter on Earth and around it. What some meeting organizers see is the need for a radio silence zone, which they call a shielded zone on the moon.

That idea has been championed by Claudio Maccone of the Istituto Nazionale di Astrofisica (National Institute of Astrophysics). In December 2021, the IAA established a new permanent committee dedicated to the protection of the far-side moon, chaired by Maccone as IAA Technical Director.

Maccone and colleagues argue that the far side of the moon is an area of ​​paramount scientific importance because it provides an environment free from the electromagnetic pollution typical of Earth.

Maccone points to the accelerating pace of multi-nation lunar missions, which could irreversibly endanger the current state of radio silence on the moon.

Some of the branches of science that would benefit greatly from operating on the other side, Maccone explains, are cosmology, astrobiology, planetary defense, as well as the search for other intelligent life that could populate the heavens.

a large round metal disk on the moon's dusty, cratered surface

a large round metal disk on the moon’s dusty, cratered surface

Moon results

Science on the moon is already taking shape, says Jack Burns, professor emeritus in the department of astrophysical and planetary sciences at the University of Colorado, Boulder.

“Radio astronomy from the moon has begun,” says Burns.

NASA’s first radio telescope, ROLSES, was recently delivered to the moon’s south pole by the Intuitive Machines Odysseus lander, Burns points out. ROLSES stands for Radio Wave Observation at the Lunar Surface of the Photo-Electron Sheath. He is a co-investigator on the ROLSES instrument now on the moon.

In addition, there are plans to land additional radio telescopes in 2026 on two other NASA Commercial Lunar Payload Services landers: ROLSES-2 on the near side and the Lunar Surface Electromagnetics Experiment – Night (LuSEE-Night) on the far side. Burns is a co-researcher of LuSEE-Night.

a cube-shaped spacecraft covered in gold foil on the surface of the moona cube-shaped spacecraft covered in gold foil on the surface of the moon

a cube-shaped spacecraft covered in gold foil on the surface of the moon

Years of anticipation

“After many years of anticipation, we are actively doing radio science from the moon. So we must also actively work to protect the far side of the moon in particular from radio frequency interference from satellites and infrastructure on the moon. surface,” Burns tells

This week’s workshop on Protecting the Far Side of the Moon will engage thought leaders in science, engineering, space policy and space law, Burns says, to develop modern approaches to protecting the far side of the Moon from anthropogenic radio emission.

“We must keep the other side for exciting science, including measuring magnetic fields associated with potentially habitable exoplanets and uncovering the mysteries of the undiscovered Dark Ages of the early universe – using low radio frequency observations.” says Burns.

Top level tasks

There are a number of themes running through this week’s symposium.

In defining how different branches of science benefit from a radio silence zone, the IAA’s Maccone highlights top exploration tasks:

  • Cosmology: To detect the extremely weak radiation from the hydrogen line at 142 Megahertz and switch it back to much lower frequencies. The radio silence on the far side of the moon would provide a major leap forward in research.

  • Astrobiology: Studying prebiological interstellar molecules by searching for faint spectral lines using advanced radio telescopes in combination with the radio silence on the far side of the moon.

  • Planetary defense: On the other hand, radar and optical telescopes can be used for precise measurements of near-Earth objects to increase the turnaround time of their detection and warn of a possible space rock hitting our planet.

  • SETI and technosignatures: To search with very little noise for ‘signatures’ of alien civilizations that would reach us extremely faintly due to the enormous distances between stars in the Milky Way, or even of other galaxies.

a yellow rectangle with a round black line through it and the text a yellow rectangle with a round black line through it and the text

a yellow rectangle with a round black line through it and the text

Shielded zone

Recent lunar missions and, even more, newer programs will bring more and more artificial systems around and on the moon’s surface, occupying space and emitting radio waves at different frequencies, Maccone explains.

There are already international regulations and resolutions aimed at protecting every shielded zone on the moon – SZM in lunar jargon – such as the radio regulations of the International Telecommunication Union (ITU).

“However, it is of paramount importance to take a further step, both to extend the protected frequencies to all other scientifically relevant frequencies – in addition to those already included – and to make part of the other side exclusive to scientific installations,” Maccone proposes.

Diplomatic efforts

There is an urgent need, Maccone says, to translate regulations into enforceable and binding treaties for every space agency and private company.

Maccone adds that all objectives can only be pursued and achieved through diplomatic efforts involving spacefaring nations, current and future, from around the world.

The newly formed IAA Committee and the ultimate goal of the symposium is to help form an international agreement, ideally among relevant specialized organizations, such as, for example, the ITU and the United Nations Committee on the Peaceful Uses of Outer Space.

Uniform articulation

Richard Green is chairman of the International Astronomical Union group looking into the issues of staging astronomy from the moon. He is also associate director of government relations at Steward Observatory, run by the University of Arizona in Tucson.

“I think this meeting is important because we can make some progress in uniformly articulating astronomical needs and a proposed policy approach for the moon,” Green said.

Moreover, there is an immediate opportunity to do this, Green explains, through a proposed United Nations scientific and technical subcommittee action team.

That U.N. action team would explore communications and cooperation for lunar activities and could possibly be approved at the meeting of the full U.N. Committee on the Peaceful Uses of Outer Space in June, Green said.

Wild West scenario


– Moon group urges protection of the ultra-quiet far side of the moon

— Radio telescope will launch to the far side of the moon in 2025 to hunt for the cosmic Dark Ages

– China will launch the first ever sample return mission to the far side of the moon in 2024

“My concern is that lunar projects are developing quickly and not being coordinated,” says Joseph Silk, an astrophysicist at Johns Hopkins University in Baltimore, Maryland and professor of physics at the Institut d’Astrophysique de Paris.

Scientific projects are at the forefront, Silk says, such as unique radio telescopes that can look back in time to the dark ages of the universe. The other side offers a unique environment, he adds, and optical telescopes in permanently shadowed polar craters will eventually image the nearest exoplanets.

“Yet we run the risk of a Wild West scenario due to the rivalry between competing space agencies and commercial interests,” Silk tells “The number of desirable lunar locations is limited. The last major space treaty dates from 1967 and has no means to enforce it. A new international space treaty is urgently needed,” he concludes.

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