Should we consider putting telescopes on the Moon?
Telescope observations suffer from light pollution in the optical colors and from radio noise at longer wavelengths. To tune to radio frequencies in particular, there are very few places on Earth that are still free of television and mobile phone signals. These signals interfere with the radio waves arriving from space, and in doing so prevent us from detecting faint signals from the distant universe.
The high radio sensitivity is one approach to solve the problem of what is this mysterious energy that appears to exert a kind of negative pressure on matter all across the universe that we call ‘dark energy?’
To address this question that is of interest to all physicists and astronomers, large radio telescopes are being constructed in two locations: (1) in western Australia for a project called the Single Kilometer Array (SKA) and (2) in South Africa for a project called the Hydrogen Intensity and Real Time Analysis eXperiment (HIRAX).
As one may have guessed, these are some rare ‘radio quiet’ locations left on this planet. Such experiments will enable us to come to make significant progress towards solving the problem of what is dark energy, that is unless the radio noise even in these two relatively remote places is still too large, or becomes too large by the time the telescopes are constructed and in use.
Other promising frontiers include taking the radio telescopes into space, or to the Moon. Of these, the Moon tends to have more public appeal. One can imagine winning a lottery ticket that would enable a holiday at a hotel on the Moon, replete with a Moon walk (or rather a Moon bounce), and lovely dinners in the environmentally-controlled restaurant unit while taking in the views of the entire Earth in the lunar sky.
Meanwhile, the immediate advantage of a lunar telescope from the scientist's perspective is that there is a dark side. It turns out that the Moon is tidally-locked to Earth, such that the Moon keeps its same face to the Earth at all times.
One can in principle make good use of this fact by placing telescopes on the radio-quiet dark side, and then posting the solar energy panels to fuel operations on the bright side. Is this a good use of the Moon? What do you think?