American astrophysicist Brian Luckey has estimated the probability of the existence of intelligent extraterrestrial civilizations in the observable part of the Universe. A preprint on this research is available at arXiv.org.
Based on an estimate of the likelihood of civilizations emerging in a suitable location for this, as well as using Bayesian inference, Luckey showed that with a probability of 18 percent, aliens exist in the observable part of the universe.
Depending on the combination of parameters required for the emergence of intelligent life, the probability of its existence in the world ranges from 1.4 to 48 percent.
As the factors determining the emergence of civilization, the scientist names the type of luminary, the mass of the planet and the distance between it and the star, as well as estimates of the diversity of genetic material for the emergence of various forms of life.
According to earlier estimates of scientists, human civilization is unique in the observable part of the Universe only when the probability of the emergence of intelligent life on a suitable exoplanet is ten to the minus 22nd power.