Astronomers now believe that every star in the galaxy has a planet, and they speculate that up to one fifth of them have an Earth-like planet that might be able to harbor life, but we haven't seen any of them.
Astronomer tror nu, at hver stjerne i galaksen har en planet, og de formoder, at op i mod en femtedel af dem har en jord-lignende planet, som kan rumme liv, men vi har ikke set nogle af dem.