Lasers could communicate with nearby extraterrestrial intelligence

Scientists believe that an infrared ray of light launched into space can become the first step to communicating with other civilisations by means of conventional signals such as the Morse code.


According to the authors of the scientific work, James Clark and Kerry Cahoy from the Massachusetts Institute of Technology (MIT), such a signal can be detected by astronomers of hypothetical extraterrestrial civilisations, especially those who are in nearby star systems, such as Proxima Centauri b, the closest star to the Earth, or the TRAPPIST-1, located at a distance of 40 light years, around which seven exoplanets orbit, three of which are potentially inhabited. If this signal is seen from these nearby systems, then the same laser can be used to transmit a short message in the form of pulses just like Morse code.


It has been shown that if a laser with a power of 1-2 megawatts is focused with a powerful telescope with a diameter of 30-45 metres, and the beam is focused so that it is directed into space, the result will be an infrared flux that is powerful enough to stand out amidst the Sun’s infrared radiation.


Astronomer James Clark thinks that if aliens really exist in the galaxy, then humankind is fully capable of finding signs of life activity. This laser technology will create a very powerful infrared radiation, comparable to the energy of the Sun. If aliens possess good will towards humans and will perceive this signal as a friendship offer, then communication between different civilisations in the form of laser pulses, such as Morse code, is quite real.


According to the study, “With technologies and facilities that exist now or will be constructed within the next decade, humanity is capable of producing signals detectable against the Sun to even cursory photometric or spectrometric observations. However, the logistics and probabilities of contacting extraterrestrial intelligence are daunting; even if extraterrestrial intelligence does exist 'nearby' in galactic terms, it is vanishingly unlikely that a conversation could be held within human lifetimes”.


However, in order to achieve the goal of transmitting such a signal, it will be necessary to use telescopes with a much larger aperture than those that exist now. One such telescope is the ELT (Extremely Large Telescope), which is in the plans to be built in Chile. The diameter of its main mirror is about 39 metres. Now the construction of the Giant Magellan Telescope with a 24-metre aperture is underway: its power may not be enough, but, according to the authors of the paper, the completion of its construction in 2024 will speed up the development of larger telescopes.


Image credit: ESA/Hubble & NASA