Placing an astronomical telescope on the surface of the Moon would allow humans to conduct more detailed space exploration missions. With each advancement in technology, we make astonishing and awe-inspiring discoveries about the Universe. So, what’s our next step in the field of space observation? Based on a recent study published on arXiv, the surface of the Moon could be a suitable choice for setting up an astronomical observatory.
In essence, placing telescopes on the Moon is not a new concept. In fact, NASA has allocated a significant budget to investigate the feasibility of the Lunar Crater Radio Telescope (LCRT) project, which involves placing a radio telescope in a lunar crater. During the Apollo missions, astronauts placed retroreflectors on the Moon’s surface to allow astronomers to measure the distance to the Moon within millimeter accuracy.
An astronomical telescope placed on the surface of the Moon would enable humans to “peer deeper” into space compared to telescopes positioned on Earth or in our planet’s planetary orbits.
While far-side lunar telescopes like LCRT may be the most popular proposal, other lunar radio telescopes, such as the Lunar Farside Telescope Array for Low-Frequency Radio (LFTALP), are also considered feasible. LFTALP would be an array of radio telescopes with 6.5-meter-wide antennas, focused on studying the atmospheres of exoplanets as they transit their stars.
However, the common challenge with all these proposals lies in the technical construction phase, which would be a formidable challenge even on Earth. In other words, the idea of building lunar radio telescopes or similar devices is an ambitious goal, but it currently exceeds our technical capabilities.
Therefore, the research team has proposed a somewhat simpler idea. A basic optical telescope could leverage the lunar terrain. The power of an optical telescope largely depends on the size of the primary mirror and the telescope’s focal length. On Earth, focal length can be increased by using multiple mirrors.
Here, a super astronomical telescope could utilize mirror arrays placed along the terrain of a lunar crater. The telescope’s detector cluster could then be suspended by cables, similar to how detectors at the Arecibo Observatory were suspended above.
Because the mirror panels wouldn’t need to be large, they would be much easier to manufacture. Meanwhile, the geological features of the lunar crater would also require less excavation and make it easier to position the telescope accurately.
A variation of this idea is to place the mirror on one side of the lunar crater and the instrument on the other. This would allow for a very long focal length, but the observation range of such a telescope would be limited.
Overall, all these ideas are still in their infancy. Moreover, there are serious challenges beyond construction to consider. For instance, lunar dust would accumulate on the mirrors over time and need to be removed. And while the Moon experiences fewer seismic activities than Earth, it can still affect the alignment of mirrors and detectors. But one thing is clear: we will return to the Moon in the near future. Once humans have set foot on this satellite, an observatory placed on the Moon is only a matter of time.