E.T., we’re home
Existing laser technology could be fashioned into Earth’s “porch light” to attract alien astronomers, reports MIT News.
A new study from the Massachusetts Institute of Technology (MIT) proposes to create a cosmic beacon, with available laser technology, strong enough to attract potential aliens located as far as 20,000 light-years away.
The research, called “feasibility study,” appears in the Astrophysical Journal.
The findings suggest that if a 1 to 2-megawatt high-power laser were to be focused through a massive 30 to 45-meter telescope and into space. This combination would produce a beam of infrared radiation strong enough to stand out from the sun’s energy.
Furthermore, scientists explain that once this signal is picked up by potential alien civilization, we could use the same system to transmit brief messages in order to communicate with aliens.
“If we were to successfully close a handshake and start to communicate, we could flash a message, at a data rate of about a few hundred bits per second, which would get there in just a few years,” explained author James Clark, a graduate student in MIT’s Department of Aeronautics and Astronautics.
The best part is that the technology needed to get this working is already available to use, and such an instrument could soon be developed.
“This would be a challenging project but not an impossible one,” Clark explains.
“The kinds of lasers and telescopes that are being built today can produce a detectable signal so that an astronomer could take one look at our star and immediately see something unusual about its spectrum. I don’t know if intelligent creatures around the sun would be their first guess, but it would certainly attract further attention.”
Several possible configurations were considered by experts before the eventually picked two that would work best for their design.
By using a 2-megawatt laser, and putting it through a 30 meter-telescope, we could produce a powerful signal that could be picked up clearly from Proxima Centauri B, one of the planets closest to our sun, and possibly home to alien life.
By using a 1-megawatt laser, and putting it through a 45-meter telescope, we could then produce a signal that is powerful enough to be intercepted by anyone inhabiting the Trappist-1 system, located 40 light-years away from Earth.
However, Clark explains that both options could be detectable as far as 20,000 light-years away.
But while this plan may sound attractive and could help us find out whether we are alone in the cosmos, the plan has a few risks.
Despite the fact that shinning the powerful laser through the telescope would not be something that you could see with the naked eye, the powerful beam could disrupt spacecraft instruments on its path and could also harm a person’s eyesight if he or she were to stare directly at it.
Clark explains that “If you wanted to build this thing on the far side of the moon where no one’s living or orbiting much, then that could be a safer place for it.”
“In general, this was a feasibility study. Whether or not this is a good idea, that’s a discussion for future work.”
It wouldn’t work the other way around
While this plan could work for us if we were to try and signal aliens’ hey we are here’, the same thing wouldn’t work the other way around.
According to scientists, if the roles were reversed, and we were instead to look for a similar laser beacon coming from space, it would be difficult to spot with currently available technology.
“It is vanishingly unlikely that a telescope survey would actually observe an extraterrestrial laser unless we restrict our survey to the very nearest stars,” Clark explains.
“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 adds.
“However, 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 E.T. is phoning, we will detect it.”