Clyde Tombaugh : biography
Interest in UFOs
Tombaugh was probably the most eminent astronomer to have reported seeing unidentified flying objects and to support the extraterrestrial hypothesis. On August 20, 1949, Tombaugh saw several unidentified objects near Las Cruces, New Mexico. He described them as six to eight rectangular lights, stating: "I doubt that the phenomenon was any terrestrial reflection, because… nothing of the kind has ever appeared before or since… I was so unprepared for such a strange sight that I was really petrified with astonishment." Tombaugh observed these rectangles of light for about 3 seconds and his wife saw them for about 1½ seconds. He never supported the interpretation as a spaceship that has often been attributed to him. He considered other possibilities, with a temperature inversion as the most likely cause.The World of Flying Saucers: A scientific examination of a major myth of the space age, by Donald H. Menzel and Lyle G. Boyd, 1963, Doubleday, pp. 266-70.From my own studies of the solar system I cannot entertain any serious possibility for intelligent life on other planets, not even for Mars… The logistics of visitations from planets revolving around the nearer stars is staggering. In consideration of the hundreds of millions of years in the geologic time scale when such visits may have possibly occurred, the odds of a single visit in a given century or millennium are overwhelmingly against such an event. A much more likely source of explanation is some natural optical phenomenon in our own atmosphere. In my 1949 sightings the faintness of the object, together with the manner of fading in intensity as it traveled away from the zenith towards the southeastern horizon, is quite suggestive of a reflection from an optical boundary or surface of slight contrast in reflective index, as in an inversion layer. I have never seen anything like it before or since, and I have spent a lot of time where the night sky could be seen well. This suggests that the phenomenon involves a comparatively rare set of conditions or circumstances to produce it, but nothing like the odds of an interstellar visitation.
Another sighting by Tombaugh a year or two later while at a White Sands observatory was of an object of −6 magnitude, four times brighter than Venus at its brightest, going from the zenith to the southern horizon in about 3 seconds. The object executed the same maneuvers as in Tombaugh’s first sighting.
Tombaugh later reported having seen three of the mysterious green fireballs, which suddenly appeared over New Mexico in late 1948 and continued at least through the early 1950s. Despite this, the final report of Project Twinkle claimed that he "… never observed an unexplainable aerial object despite his continuous and extensive observations of the sky."
In 1956 Tombaugh had the following to say about his various sightings: "I have seen three objects in the last seven years which defied any explanation of known phenomenon, such as Venus, atmospheric optic, meteors or planes. I am a professional, highly skilled, professional astronomer. In addition I have seen three green fireballs which were unusual in behavior from normal green fireballs… I think that several reputable scientists are being unscientific in refusing to entertain the possibility of extraterrestrial origin and nature."
Shortly after this in January 1957, in an Associated Press article in the Alamogordo Daily News titled "Celestial Visitors May Be Invading Earth’s Atmosphere," Tombaugh was again quoted 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."