Is there anyone out there?
This is an age-old question that researchers have now shed new light on with a study that calculates there could be more than 30 intelligent civilizations throughout our Galaxy. This is an enormous advance over previous estimates which spanned from zero to billions.
One of the biggest and longest-standing questions in the history of human thought is whether there are other intelligent life forms within our Universe. Obtaining good estimates of the number of possible extraterrestrial civilizations has however been very challenging.