On January 3, 1999, NASA’s Mars Polar Lander roared away from Earth on a bold mission to explore a unique region of the red planet. The spacecraft was to gently set itself down near the border of Mars’ southern polar cap, the first ever spacecraft to study the distant world’s polar environment. After months of crossing interplanetary space, Mars Polar Lander was in the final minutes of slowing itself down, ready to make a self-controlled touch down. It was never heard from again. Nobody knows for sure exactly what occurred at journey’s end.