Tombaugh's first brush with extraterrestrial mystery took place on August 27th, 1941, when he reported seeing a bright flash on the surface of Mars. In 1949 he told Commander Robert McLaughlin, the Naval Missile Director at White Sands Missile Range, that he attributed the Martian flash to an atomic blast.
Pluto's discoverer reported witnessing a formation of six to eight rectangular-shaped objects racing across the skies of Las Cruces, New Mexico on August 20th, 1949. Tombaugh did not jump to any extraterrestrial conclusions about this sighting, believing what he witnessed may have been the result of thermal inversion. Nevertheless, the astronomer admitted to being "petrified with astonishment" as he observed the objects in the sky.
Tombaugh also reported witnessing three of the mysterious green fireballs that were frequenting the skies over New Mexico in the late Forties and early Fifties. Once again, the astronomer refused to leap to the conclusion that this phenomenon was the result of visitors from outer space. But he did write that it was actually "unscientific" for reputable scientists to refuse to entertain the possibility that the green fireballs were intelligently controlled craft of extraterrestrial origin.
Tombaugh was quoted in an Associated Press article in 1957 on his sightings and opinion about them. "Although our own solar system is believed to support no other life than on Earth, other stars in the galaxy may have hundreds of thousands of habitable worlds. Races on these worlds may have been able to utilize the tremendous amounts of power required to bridge the space between the stars..." Tombaugh stated that he had observed celestial phenomena which he could not explain, but has seen none personally since 1951 or 1952. "These things, which do appear to be directed, are unlike any other phenomena I ever observed. Their apparent lack of obedience to the ordinary laws of celestial motion gives credence."
