National Geographic presents the science, the goals, and the anticipation of humankind's most ambitious planetary expedition ever: the Curiosity mission to Mars. On August 6, 2012 (EST), NASA's Curiosity spacecraft will complete its 255-day, 354-million-mile journey and plunge down into Gale Crater, its target on the martian surface, decelerating from 13,200 to 0 mph in 7 minutes. The whole world will be watching this, the most complicated and precise landing ever undertaken, and wondering: What's the inside story on this Curiosity mission, and what do NASA scientists hope Curiosity will find? In this e-short, written by Washington Post science correspondent Marc Kaufman and published just as the suspense builds, with Curiosity hurtling toward Mars, space science readers, techies, and informed news junkies will find answers to these and other fascinating questions about the red planet.