So much so that it raises the question, were aliens watching us 30 years before the fabled crash landing at Roswell, New Mexico?
Some of these spectacular sightings feature in a new book, UFOs of the First World War, by Nigel Watson.
The most famous flyer of the First World War was the German pilot Manfred Freiherr von Richthofen, better known as the Red Baron.
He supposedly spotted an UFO that looked like an upside down silver saucer with orange lights during an early morning mission in the clear blue skies above Belgium in the spring of 1917.
Fellow German Air Force ace Peter Waitzrick, who reportedly witnessed the dogfight, said: “We were terrified because we’d never seen anything like it before. The Baron immediately opened fire and the thing went down like a rock, shearing off tree limbs as it crashed into the woods.”
Two occupants allegedly survived the crash and clambered from the wreck before running into the trees.
Waitzrick and his squadron initially thought the UFO was a secret US aircraft, until he read reports about flying saucers and then had no doubt that was what he saw.
Waitzrick said: “There’s no doubt in my mind that the Baron shot down some kind of spacecraft from another planet and those little guys who ran off into the woods were space aliens of some kind.”