E.T., we’re home
If extraterrestrial intelligence exists somewhere in our galaxy, a new MIT study proposes that laser technology on Earth could, in principle, be fashioned into something of a planetary porch light — a beacon strong enough to attract attention from as far as 20,000 light years away. The research, which author James Clark calls a “feasibility study,” appears today in The Astrophysical Journal. The findings suggest that if a high-powered 1- to 2-megawatt laser were focused through a massive 30- to 45-meter telescope and aimed out into space, the combination would produce a beam of infrared radiation strong enough to stand out from the sun’s energy. Such a signal could be detectable by alien astronomers performing a cursory survey of our section of the Milky Way — especially if those astronomers live in nearby systems, such as around Proxima Centauri, the nearest star to Earth, or TRAPPIST-1, a star about 40 light-years away...