This beacon would be able to attract attention from as far as 20,000 light years away from Earth. The research suggests that a high-powered 1 to 2-megawatt laser could be focused through a 30 to 45-meter telescope and aimed into space. That combination would create a beam of IR radiation strong enough to stand out from the sun’s energy.
That signal could be detectable by an alien astronomer performing a survey of our section of the Milky Way galaxy, especially if the astronomers were in nearby star systems like Proxima Centauri. MIT researchers claim that if an alien astronomer was searching the heavens from TRAPPIST-1, the nearest star to Earth with potentially habitable planets, the massive laser could be used to send a brief message in the form of pulses similar to Morse code.
A message sent in this manner would have a data rate of a few hundred bits per second and could arrive at the distant planet in a few years. One of the researchers on the project says that most of the tech to do this exists now, and what doesn’t exist could be developed in the near term.
Potential issues with this plan include that despite that the IR beam is invisible, it would damage people’s vision if they looked directly at the beam. This beam would have a flux density of about 800 watts per square meter, close to the sun’s 1300 watts per square meter flux density. A safer location than Earth would be on the far side of the moon. Any distant astronomer looking at our section of the galaxy would also have to look directly at the laser to see the beam making detection of the beacon highly unlikely, admits researchers.
Read the original article on slashgear.com.
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