Гарвардські астрономи розрахували що відповідь від інопланетян займе 3000 років

Harvard astronomers calculated that if any transmissions from Earth were heard by an extraterrestrial technological civilization (ETC), it would take about 3000 years to get a reply.

https://www.universetoday.com/152112/well-have-to-wait-about-3000-years-for-a-reply-from-intelligent-civilizations/