The Clarke exobelt, a method to search for possible extraterrestrial civilizations

A new study published in the Astrophysical Journal by Hector Socas-Navarro, a researcher at the IAC, examines the possibility of detecting hypothetical artificial satellites orbiting around other worlds.

Finding life in other parts of the universe is one of humanity's enduring dreams. For the first time in history, the scientific community has hopes that this dream will become a reality in the not too distant future. This is, in part, due to the new generation of giant telescopes, presently in the planning phase, with which astronomers hope to make detailed analyses of the atmospheres of planets beyond the solar system. For this reason, researchers are making efforts to investigate biomarker evidence of life on these planets.

However, finding intelligent civilizations, or technological capacity, seems much less likely. To start with, researchers lack "technomarkers," the analogues of biomarkers, revealing the presence of technology. Since the 1980s, there have been searches for radio signals from other civilizations, so far unsuccessful. This is hardly surprising since the radio emissions from a society like ours would not be detectable at interstellar distances unless they were deliberately focused in the direction of the receiver. In the scientific literature, there have been proposals to look for technomarkers, for instance, so-called "Dyson Spheres," hypothetical artificial megastructures constructed around a star to collect its light and thereby supply the energy of a civilization much more advanced than ours.

In an article published today by the IACresearcher Hector Socas proposed a new technomarker, which is characterized by the fact that it could be produced by present-day technology on Earth. There is a region in space around planets called the "Clarke Belt," in honour of Arthur C. Clarke, who in 1945, published an article about the use of geostationary orbits for telecommunications. In this belt are geostationary satellites used for a large number of practical applications.