The Curiosity rover has made its most unusual discovery yet on Mars: rocks made of pure sulfur. And it all started when the 1-ton rover happened to drive over a rock and crack it open, revealing yellow-green crystals never before seen on the Red Planet.
"I think it's the strangest find of the entire mission and the most unexpected," said Ashwin Vasavada, Curiosity project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. "I have to say, there's a lot ...
