What do British astronomers, little green men, and pulsars all have in common?
Last time we mentioned the time when Soviet radio astronomers went public about listening in on radio signals from an alien civilization. As it turned out, what they were actually listening to was a quasar: the blazing core of a galaxy that can emit radio waves that fluctuate in a regular pattern. So regular, in fact, that people thought it was an alien intelligence. Learn more on this Moment of Science.