Signals of Extinct Extraterrestrial Civilizations –“Echo Throughout the Milky Way”

  “For all we know, if galactic radiation-emitting civilizations exist, they could be located anywhere in the Milky Way. A signal reaching Earth could thus be as old as about 90,000 years, that is the time it takes for electromagnetic waves to cover the distance between us and the opposite edge of our galaxy, and … Continue reading Signals of Extinct Extraterrestrial Civilizations –“Echo Throughout the Milky Way”