2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Lasers can be used to communicate with extraterrestrial civilizations, astrophysicists report in an article published in The Atrophysical Journal. They calculated that hypothetical astronomers on Proxima Tsentravra b - an exoplanet that orbits a star 4.2 years from Earth - would be able to pick up a signal sent by a two-megawatt laser and an optical telescope with a mirror 35 meters in diameter.
The SETI project has also been studying the possibility of establishing contact with extraterrestrial civilizations for several years. Earlier, representatives of the project, for example, suggested using a special Martian "sailboat", with the help of which it would be possible to send beams of microwave magnetic radiation. The researchers also suggest that civilized extraterrestrial life will build artificial satellites and engage in space exploration, which will lead to the formation of space debris, the presence of which can change the light curve of a star at the time the body passes through its disk.
In a new work, James Clark and Kerri Cahoy of the Massachusetts Institute of Technology proposed using lasers to communicate with extraterrestrial civilizations. They calculated that if you use a powerful laser and focus its beam with an optical telescope, then the infrared radiation of the received signal can reach exoplanets, both orbiting the nearest to us Proxima Centauri, and planets in the TRAPPIST-1 system, which are located at a distance of 40 light years from Earth. According to scientists, such rays can be a kind of beacons, the light from which spreads over distances of up to 20 thousand light years.
For example, powerful laser systems developed by the military already possess the required power. Scientists clarify that the laser will need to be installed at high points, like powerful telescopes, in order to reduce interference (noise) in the Earth's atmosphere, which can interfere with signal transmission.
It should also be noted that to achieve the goal of transmitting such a signal, telescopes with a much larger aperture will have to be used than currently exist. One such telescope is the ELT (Extremely Large Telescope), which is planned to be built in Chile. The diameter of its main mirror is about 39 meters. The construction of the Giant Magellanic Telescope with a 24-meter aperture is also underway: its capacity may not be enough, but, according to the authors of the work, the completion of its construction in 2024 will accelerate the development of larger telescopes.
The way of communicating information is one task that needs to be solved in order to successfully communicate with possible life outside the Earth. The other is a means of communication - a language that can be understood by other civilizations. Read about attempts to solve this problem and why they have not been successful so far in our blog.