Astronomers propose finding alien civilizations by searching for unusually cold stars that could be surrounded by Dyson swarms—energy-harvesting structures first proposed by Freeman Dyson.

As Nicolas Roeg’s enigmatic, unclassifiable film – in which David Bowie plays an alien visiting Earth – turns 50, we look back at Tom Milne’s deciphering of it. From our Summer 1976 issue.

If someone told you there’s a place in Colorado specifically built for watching aliens, you’d probably assume it was a joke.

As per a new study, Dyson spheres around faint stars in the galaxy could offer new techno-signatures clues.