Is There Any Evidence for Extraterrestrials Visiting Earth?
Since the first widely-publicized UFO (unidentified flying object) incident, in Roswell, New Mexico, on 7 July 1947, there have been thousands of UFO sightings per year. Since then, many have speculated that UFOs may be spaceships used by extraterrestrials to visit Earth. A 2006 survey found that 24.6% of Americans agree or strongly agree that at least some UFOs are spaceships from other worlds. Working against this 24.6%, however, is an absence of physical evidence. Despite decades of eyewitness reports, including those of first-hand contact with extraterrestrials, no physical evidence has turned up. Not a single extraterrestrial machine, scrap of extraterrestrial fabric, fleck of paint, strand of extraterrestrial hair, or anything else that could be definitively put under a microscope and identified as not originating from the Earth. Low earth orbit is constantly being extensively monitored by powerful radar and long-exposure space-based cameras. Tracking systems are capable of detec
