BOULDER, Colorado – Astronomers have always sought out remote and isolated places from which their precise observations of the surrounding universe can be made. Now add another distant place – the moon.
But the international scientific community is increasingly concerned about the need to protect the far side of the Moon from human-made radiofrequency intrusions.
The far side of the Moon always faces the Earth. As a result, it’s ‘silent’, shielded by the moon itself from radio frequency interference (RFI) crackling through space, pumped out by powerful Earth-based transmitters.
For years, placing a radio telescope on the far side of the moon has been considered the prime location to conduct unparalleled studies, such as giving an extraordinary ear to listen for signs of extraterrestrial intelligence.
A newly established Far Side of the Moon Protection Standing Committee of the International Academy of Astronautics (IAA) based in Paris, France, has begun to define the problem and possible solutions to guard against RFI from the lunar hidden face, ideal landscape, they say, for a future. radio telescope or phased array detector.
Additionally, the International Telecommunications Union, based in Geneva, Switzerland, has pledged to define and protect what it calls the moon’s protected area. However, future lunar exploration missions, the ITU warns, could spoil this pristine radio environment with uncontrolled radio emissions and even enhance the lunar exosphere, the ultra-vaporous layer of gas that acts as an atmosphere.
With the first radio telescope landing on the Moon later this year as part of NASA’s Commercial Lunar Payload Services program, radio astronomy from the Moon is beginning in earnest, said Jack Burns, a space scientist at the University of Colorado at Boulder. This radio astronomy instrument is called ROLSES, he said, an observation of radio waves on the lunar surface of the photoelectron sheath. It will fly on the private Intuitive Machines lander.
“This will be followed by a radio telescope on the far side of the Moon in 2025 and hopefully radio dipole antenna arrays later in the decade. So now is the time to begin serious international efforts to protect the far side of the Moon as a unique reserve of radio silence for early universe exploration,” Burns said. SpaceNews.
Unique real estate
Claudio Maccone of the Istituto Nazionale di Astrofisica in Italy is an astronomer, space scientist and mathematician. As chair of the new IAA committee, he is a leading voice in maintaining the far side of the Moon as a unique ground for scientific activities.
Future space planners, Maccone argues, “must anticipate and preserve precious space resources that remain unpolluted by humanity.” Unfortunately, the undeclared but very real “new current race to the moon” complicates matters terribly, he said.
Maccone is pushing to establish a protected antipodal circle, or PAC, a large piece of lunar land about 1,130 miles (1,820 kilometers) in diameter that would become the most protected area on the far side of the moon. He said the United Nations should recognize the CAP as an international protected area – an area free from radiation contamination.
In addition, the center of the far side of the moon, in particular the Daedalus crater, is being advanced; its high rim would prevent Earth-generated “radio smog” from fouling a future radio telescope planted there or other astronomical equipment.
Blind and blind
During this time, new ideas on how to take advantage of the particular qualities of the lunar far side have come to the fore. For example, NASA’s Innovative Advanced Concepts (NIAC) program awarded study funds for a Lunar Crater radio telescope. This proposal centers on the use of crater wall climbing robots to deploy a metal mesh to form a large parabolic reflector.
Another NIAC-backed proposal located on the moon is FarView – a radio observatory made on the moon. This concept would use about 100,000 arrayed dipole antennas spread over hundreds of miles of lunar terrain. FarView science would support a detailed investigation of the unexplored “Cosmic Dark Age”, the conditions and processes under which the first accreting stars, galaxies and black holes formed.
“The far side of the moon is a unique place for us in the entire universe,” Maccone said. “It’s close to Earth, but shielded from the radio emissions we ourselves create in ever-increasing quantities, making our radio telescopes increasingly blinding.”