Aliens are serious science. The search for extraterrestrial intelligence, or SETI, constitutes major research projects at radio telescopes the world over, and it is championed by the non-profit institute that shares its name. Multiple experiments on the subject, and citizen science projects like [email protected], have been going strong for decades. Every year, papers, conferences and initiatives discuss how best to seek out — and maybe even talk to — E.T.

But it wasn’t always that way.

While UFO sightings and depictions in movies and comics spiked during the 1950s, the topic of aliens was considered unprofessional among scientists. Only a handful of professionals would speculate on the possibility of alien life, and even they made sure it was only a small part of their research. So when a group of science luminaries from a variety of disciplines met at a rural observatory in West Virginia to talk about little green men, they did so in secret.