According to The Daily Star, researcher Scott C. Waring pointed out a mysterious rectangular 'entrance' or 'doorway'. Decoding the 'Doorway'The photo was taken by NASA's Curiosity rover and shows a small, dark opening in a rock. Its shape has led UFO and conspiracy theorists to call it a doorway or entrance created by another civilisation. However strange the surface may be, NASA says some of the rover Curiosity's discoveries prove water used to flow across Mars. So while the latest 'alien doorway' looks like something straight out of a science-fiction movie, there's no proof that an extraterrestrial civilisation left it behind.