Mars just dropped a surprise golden nugget —literally. Curiosity accidentally cracked open an ordinary-looking rock, only to ...

When the rover rolled its 899-kilogram (1,982-pound) body over the rock in May last year, the rock broke open, revealing ...

Sometimes it is easy to overlook the biological importance of another essential element, sulfur, the fragrant neighbor of the elements that comprise most organic compounds. In fact, sulfur occurs ...