While there are countless examples of video evidence and interviews of people who claim to have seen a UFO, there is no official record of physical UFO evidence ever being found. Astronaut Buzz Aldrin's claim to have seen UFOs while on the moon is the most notable firsthand account.
Although physical evidence of a UFO is scant, physical evidence of extraterrestrial life was allegedly discovered in a meteorite in December 2013. Scientist Chandra Wickramasinghe and his team used an electron microscope to study a meteorite that had fallen to earth, reports Huffington Post. The group concluded that microstructures found on the meteorite samples was proof of biology in an extraterrestrial environment, though this conclusion has been disputed by other scientists.