Lasers could be fashioned into beacons to attract space-faring aliens: Study

The beam produced would be strong and distinguishable from the Sun’s light to alien astronomers.

A pair of MIT researchers think its time we made the first move and reached out to aliens, and have described what could be the right tools for the job in a new study.

Assuming extraterrestrial intelligence exists somewhere in the galaxy, the pair tested the concept of a strong-enough laser beacon that could catch the attention of aliens as far as 20,000 light years away.

This “feasibility study” carried out by MIT scientists, published in the Astrophysical Journal, justifies how all the technology needed to engineer such a beacon is already available today.

While the notion of such an alien-attracting beacon may sound silly, the study’s authors think it would increase the likelihood of a handshake with alien space-farers that may survey our nook in the Milky Way galaxy.

The planetary system closest to our Sun — Proxima Centauri, or the TRAPPIST-1 system, which hosts 3 potentially habitable planets just 40-light years away — could be great places to start, the authors told university press.

A well-crafted, continuous signal into space carrying a brief message in the form of pulses, like Morse code, for instance, would need some heavy-duty gear. Specifically, the researchers think a high-energy 1- to 2-megawatt laser source shone through a massive 35- to 45-metre telescope aimed into space would do the trick.

MIT-Alien-Beacon_0 (1)

Hello from Planet Earth! Image courtesy: MIT

The powerful beam produced by such a setup would be strong enough to be distinguishable from the Sun’s rays.

Much like some of the biggest space observatories, the researchers expect such a laser beacon to be built on top of a mountain so the laser retains as much energy as possible as it pierces through the atmosphere.

"The kinds of lasers and telescopes being built today can produce a detectable signal… an astronomer could take one look at our star and immediately see something unusual about its spectrum,” James Clark, a graduate student at MIT’s School of Aeronautics and Astronautics and author of the study, told university press.

“I don't know if intelligent creatures around the sun would be their first guess, but it would certainly attract further attention."

Clark’s study found that such a laser is, in fact, technically feasible. It may even see the light of day in months if more people saw the effort as worthwhile. One of the biggest challenges to its acceptance is the likelihood of the beam being detected by any intelligent life at all.

"With current survey methods and instruments, it is unlikely that we would actually be lucky enough to image a beacon flash, assuming that extraterrestrials exist and are making them," Clark told press.

"As the infrared spectra of exoplanets are studied for traces of gases that indicate the viability of life, and as full-sky surveys attain greater coverage and become more rapid, we can be more certain that, if ET is phoning, we will detect it."

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