After playing Ripley in the sci-fi horror 'Alien', it's easy to see why Sigourney Weaver is a believer. The film is about a highly aggressive extra-terrestrial that hunts and kills the crew of a spaceship. Scary stuff!

 

Source: http://au.thehype.yahoo.com/galleries/g/-/11345845/celebrity-ufo-enthusiasts/11345859/