Topic summary
Alien civilization
Extracted from the Wikipedia article Extraterrestrial intelligence.
Probability
The Drake equation is a probabilistic framework used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Waygalaxy. A 2020 study estimated that there could be about 36 alien civilizations in the Milky Way today. With 36 "communicating extra-terrestrial intelligent" civilizations, the average distance would be around 17,000 light-years. However, it is conceivable that some civilizations have created machines, probes or similar systems that outlast them.