UFOs: From Antiquity to Now Circular ships, vertical aerial cylinders, spheres, disks, wheels in the sky, hat-shaped things, flying pillars or columns and triangular-shaped objects. At first glance, you might think those are common, almost daily, descriptions of UFOs reported by eyewitnesses. Well, yes ... sort of. Those are the actual words, found in ancient texts, that characterize unidentified flying objects, spanning biblical accounts through the 1800s. And that's exactly what two leading researchers have done: trace the huge numbers of UFOs reported that couldn't possibly be attributed to or misinterpreted as artificially constructed objects seen in the sky. On the morning of April 14, 1561, over Nuremberg, Germany, many multi-colored spheres and disks were seen emerging from two vertical cylinders in the sky and appearing to engage in some sort of aerial fight against each other in this 16th century woodcut. In their book "Wonders in the Sky," (Tarcher/Penguin) renowned computer scientist and astronomer Jacques Vallee and scholar/historian Chris Aubeck tackle the question of how to interpret all of the unexplained aerial sightings that occurred before the age of industrialization. Vallee, who was a featured panelist discussing UFOs at last month's highly touted Global Competitiveness Forum in Saudi Arabia, served as the model for the French scientist portrayed by Francois Truffaut in Steven Spielberg's classic 1977 UFO film "Close Encounters of the Third Kind." "My passion was always about when did this phenomenon start? That's a question that any scientist should be asking when you're confronted with a new phenomenon. When did it really begin? So we wanted to go as far back as we could, and to stop before there was anything human in the sky," Vallee told AOL News. Two enormous, glowing wheels are seen in the sky over Mecklenburg and Hamburg, Germany, on Nov. 4, 1697, as a crowd watches from below. To that end, Vallee and Aubeck examined more than 500 unexplained aerial sightings, including one case from 1513 in Rome, Italy. The eyewitness: celebrated sculptor, painter and architect Michelangelo. What he saw: a flying triangle. "He was so impressed, he made a painting of it, but the painting didn't survive. We only know about it from art historians," Vallee said. "For cases like this to have survived, they had to come from people who were not weirdos and cranks, because these cases come from the archives of historians, castles, dukes and kings and the church, and they had been investigated. The cases that have survived the test of time have been the ones that have credibility." Another case, from 1663, near Bieloziero, Russia, involved a crowd of people who saw a fiery object emitting "burning beams." Vallee says a formal report was written by the St. Cyrille monastery. "There was a great sound and the people came out of the church to find out what it was, and they witnessed a large ball of fire that arrived from the cloudless heavens." Astronomer/computer scientist Jacques Vallee is convinced, after five decades of research, that UFOs represent an unexplained phenomenon and that sightings by credible eyewitnesses can be traced back through many centuries. According to the official monastery report, the object "moved along the lake, passing over the water surface. The ball of fire measured some 140 feet from one edge to the other, and over the same distance, ahead of it, two ardent rays extended ... and the big fire and two smaller ones disappeared. Less than an hour later, the people again came out to the square and the same fire suddenly reappeared over the same lake." For as long as people have been leaving behind written records of their experiences, there have been depictions of strange objects seen in the sky, some even drawn by humans on cave walls. But Vallee didn't want to go back that far, historically. "We wanted to stay away from legends and vague interpretations or even religious things because we are not the ones to comment on that. I wanted cases that had a date and a place and the name of a witness, and the time of day, if we could. "It turns out, in a surprising number of cases, we have all of that. We do have a lot of precision on who, what, where -- the questions a good cop would ask." Vallee has spent nearly 50 years looking for answers about UFOs. He asserts that the notion that man is in contact with celestial spirits or beings, and that man can travel to the stars and through the stars to higher levels, is an idea that goes as far back as you can trace civilization. A 16th century woodprint shows what appeared as aerial combat between many black spheres in the sky above Basel, Switzerland, on Aug. 7, 1566. "Yes, and once you eliminate comets, meteors, tornadoes and other natural things, you're left with something that is undistinguishable from the UFO phenomenon as we see it today." Vallee, an acclaimed scientist who co-developed the first computer-based map of Mars for NASA, is also a successful Silicon Valley entrepreneur. He's never gone on record saying he believes some UFOs may be visitors from another planet. "What I've said is that I've spent a lot of time meeting witnesses and listening to them, and the witnesses are telling me what they've seen is not a spacecraft -- not some sort of super rocket that comes down and lands with explorers coming out of it. "What they see is something that can appear out of nowhere, change very quickly into a light, back and forth from the light to a craft. And if they are telling me the truth, which I believe they do, this could be from anywhere, any time. "The thing I've objected to is the first hypothesis: that these come from some other planet somewhere. The problem is that it doesn't explain the facts and the complexity -- the fullness -- of the phenomenon. We need something more. It has to be one of the possibilities, but it's only one among many." Aerial ships and a domed saucer-shaped object can be seen in this depiction of an unusual event in the sky over Stralsund, Germany, on April 8, 1665. While many people jump to the conclusion that UFOs must be interplanetary spaceships, skeptics maintain that, one, there's no evidence Earth is being visited by anyone; and two, they couldn't get here because the distance between their home planet and ours is just too great, and they wouldn't have the technology to make the trip. Vallee's not convinced about that. "It is true that if you assume that physics is complete, and that nothing can go faster than light; if you take it that way, then it would take an extraordinary amount of time to get here. And it would be impractical in terms of energy and economics. However, even within general relativity, there are other things that are possible that would violate that idea. "The idea of wormholes, for example, are a consequence of general relativity. And if you can use wormholes to tunnel through the universe, you certainly wouldn't need to spend years and years to get to the stars." Whatever UFOs turn out to be, whether from contemporary sightings or those from many centuries into our ancient past, Vallee is convinced that something is going on and that the truth is out there. "I have a profound belief that there is an unexplained phenomenon here -- that it's extremely fundamental to human life, that it questions everything about our history and about who we are and our place on this planet and in the universe. "I also believe absolutely that there is a technology at the center of it; otherwise, I wouldn't be doing this research."