The US space agency's unmanned Curiosity rover will explore a mountain on Mars that should read like "a great novel," revealing if signs of life ever existed on the red planet, NASA said Friday. The landing site for the 2.5 billion dollar Mars Science Laboratory (MSL) was unveiled the day after the 30-year shuttle era ended with the return to Earth of Atlantis after its final mission to the International Space Station. Clues sent home from Mars are important to NASA as it aims to build a spaceship capable of toting humans there by 2030, while private companies race to...