UFO

The word 'UFO' stands for 'Unidentified Flying Object', but has come in general usage to mean a spaceship from outer space, piloted by aliens, or non-human Extraterrestrials. UFOs are often believed to be in the shape of flying saucers, but many other shapes have been reported, such as cigar shapes and triangles. The first modern sighting was made in 1947, and soon afterwards a UFO is alleged to have crashed at a town called Roswell, complete with miniature humanoid occupants. Many alleged sightings have been made since then, and many people claim to have been abducted by aliens and subjected to experimentation. Despite all these claims, no concrete evidence has ever emerged that aliens exist.