Six months after landing inside a 96-mi.-wide impact crater near Mars’ equator in August 2012, NASA’s Curiosity rover drilled out a teaspoon of gray powder from what had once been a water-soaked rock, and found some of the key ingredients necessary for life. The discovery of sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon fulfilled one of the mission’s main goals: To determine if the planet most like Earth in the Solar System ever had the chemical inventory and ...
