NASA's Curiosity Rover Accidentally Discovers Sulfur Crystals on Mars

As NASA’s Curiosity rover rolled across the Martian terrain this spring, its wheels inadvertently cracked a rock below. The crushed material revealed yellow crystals of sulfur in its pure elemental form—a first-ever discovery on Mars. The accidental find, which was caused by the heft of the car-sized, one-ton rover on the morning of May 30, came as a pleasant surprise to researchers. In addition to the crystals that Curiosity drove over, the rover identified a plain with similar rocks dotting the surrounding ground. “Finding a field of stones made of...