““the amount of time it takes to reach the Earth from these stars will be greater if the aliens can’t travel at near light speed. If they can only travel at half light speed then it would take them 44 years to get from Tau Ceti, for example. If they can only travel at one-tenth light speed then only Alpha Centauri A and B would realistically be within range – and the aliens would have to come from a planet orbiting one of those stars too.””
![“I have looked further into space than ever human being did before me. I have observed stars of which the light, it can be proved, must take two million years to reach the earth. [ Having identified Uranus (1781), the first planet discovered since antiquity .]” quote by William Herschel](https://sms4smile.com/quotes/img-quotes/ef2/william-herschel-28349_astronomy_i-have-looked-further-into-space-than-ev_2046887.jpg)
