For example if the Betelgeuze system had a planet, with a theoretical large telescope on that planet and looked back at earth. It would see life and civilizations from the 15th century a.d. (~500 light years distance)
For example if the Betelgeuze system had a planet, with a theoretical large telescope on that planet and looked back at earth. It would see life and civilizations from the 15th century a.d. (~500 light years distance)
What do you mean if? We’ve been doing that for years, and so far as I understand it, the only reason that we haven’t found any is that there are millions of solar systems to check.