On April 12, 1950, astronomers at the Palomar Observatory in Southern California captured a series of photographic plates that would later kick off one of the most intriguing mysteries in modern astronomy.
The images, taken seven years before the launch of any manmade satellites, were part of a routine survey of the night sky. They revealed nine points of light, each resembling a distant star to the human eye. However, these lights appeared in only one set of photographs. In images taken just moments before and immediately after, the points of light simply weren’t there.
The transients, as they are now called, were discovered by Beatriz Villarroel, a postdoctoral researcher at the Nordic Institute for Theoretical Physics. Villarroel had been reviewing old photographs of the night sky in 2021 to find signs of other transient celestial events such as supernovas and quasars.
While singular transients were not uncommon, never before had astronomers captured images of nine such objects appearing and disappearing simultaneously. Could these lights be something altogether different—perhaps even extraterrestrial in origin?
