There are, as best we can estimate, hundreds of billions of galaxies in the universe. (There may be more.) Average galaxies carry the weight of hundreds of billions of stars. If a habitable planet whirls around just one star in every million, the number of worlds which could harbor life would number in the…
Every scientific breakthrough has taken time to get going. Knowledge and technology needs to slowly accrue over time until a tipping point is reached. But in some cases, time just isn't a factor. Can we say that some things will never happen because they haven't happened yet?
Some astronomers think detecting an extraterrestrial radio signal is a matter of when, not if. What goes on in the immediate aftermath of such a discovery? Here's what happened the last few times we thought we'd heard from E.T.