Since the Moon always presents the same face to the Earth, a radio telescope on its far side would have the advantage of being able to “listen” to the cosmos while being completely sheltered radio waves emitted by our civilization.
The problem is that our civilization is beginning to expand around the Moon: the mining projects put forward in recent years by different countries, and even by private companies, suggest that, in the next decade, the Moon could be visited by more than 200 space probes, in orbit and on its surface. And the more these machines are, the more they will need other satellites in orbit to provide telecommunications —therefore, more “noise”.
Researchers have recently expressed concern about this, within the framework of a congress on lunar astronomy in the next decade, organized in February by the Royal Society of London.
At the very least, among these numerous lunar craft, there is one which must precisely study the particular conditions of the far side for radio astronomy: the Lunar Surface Electromagnetic Experiment (LuSEE), scheduled for 2026. Its three-meter-long antennae, forming a cross, will attempt to measure the “cosmic dawn”, epoch corresponding to the appearance of the first stars. A challenge, even in the current silence of the far side: the “emission” power of this signature of the young cosmos is estimated to be one hundred thousandth of the “noise” produced by our galaxy.
In theory, notes a recent report from the magazine Nature, it would be possible to limit the interference. If we consider that, on Earth, local initiatives have given rise to radio silence zones in the vicinity of certain radio astronomy observatories, it might be possible to reduce the “noise” of machines in lunar orbit. Provided that these new players do not see it as an obstacle to their ambitions…
Image: Artist’s rendering of a radio telescope set in a crater / Vladimir Vustyansky / JPL / NASA
