Not quite as common these days, however, are stories of individuals claiming to have had contact with extraterrestrials. In his new documentary, Calling All Earthlings, filmmaker Jonathan Berman takes a look back at one of the most famous of these “contactees,” George Van Tassel. The film captures an aspect of UFO belief that often escapes skeptical outsiders—that it wasn’t so much anxiety about alien visitors as enthusiasm and hope that attracted believers to the idea of extraterrestrial contact.

Beginning in 1927 as an airplane mechanic right out of high school, Van Tassel had a long career in aviation, first with Douglas Aircraft, then with Hughes and Lockheed. At Hughes he was involved in flight testing near Barstow, California, where he was attracted to the “clean air, the intense quiet nights, and outdoor living in the desert.”

It was there that Van Tassel got to know an eccentric German-American by the name of Frank Critzer, who had carved out a “cave home” from a natural landmark known as Giant Rock in the Mojave Desert near Landers, California. Critzer came under government investigation in the early days of World War II for reasons that are not entirely clear, but most likely involved his use of dynamite. When local police came to Giant Rock to question him in July 1942, Critzer set off an explosion that resulted in his own death.