Neil deGrasse Tyson explains the relatively recent phenomenon of UFO footage and if they in fact mean aliens are visiting us. We've been wondering whether we are alone in the Universe since the dawn of civilization. But it's only in recent years that this question has gotten much much more ...

American astrophysicist Neil deGrasse Tyson gives his take about UFO sightings and alien intelligence in general. There is a lot of video footage circulating over the internet where supposedly crafts out of this world have come to visit Earth. But do any of them hold validity? Neil degrasse ...