NASA's Curiosity rover discovers clay on the surface of Mars

Clay discovered on Mars that formed when soil mixed with water may give crucial clues to life that once lived on the now-barren planet billions of years ago. NASA's six-wheeled Curiosity rover has discovered the material on the martian surface beforehand - but never in such large quantities. Curiosity marked the occasion with an impressive selfie via its Mars Hand Lens Imager (MAHLI), a camera on the end of the rover's robotic arm. NASA's six-wheeled robot has found clay on the martian surface beforehand but never before in such large quantities. It was also marked with an impressive selfie of the Curiosity rover via its Mars Hand Lens Imager (MAHLI), a camera on the end of the rover's robotic arm (pictured) The momentous discovery was made in an area aptly known as the'clay-bearing unit' on the incline at the base of Mount Sharp, a 3.4 mile-high (4.5km) mountain.