Curiosity Rover finds round 'ball' on Martian surface
NASA's Curiosity Rover has made an unexpected discovery on its photographic mission to Mars - a near-perfect spherical rock on the surface of the red planet.
A picture of the rock was uploaded to the mission's website on September 11 showing it sitting on a dusty outcrop.
But before we get too excited at the thought of martian golfers or tennis players, NASA believes it is a completely natural phenomenon.
Discovery News quoted scientists from NASA’s Jet Propulsion Laboratory as saying the strange rock was a concretion, a compact mass of matter formed by the precipitation of minerals found in sedimentary rocks.
When a sedimentary rock is formed, minerals seep into the the rock's pores.
These minerals are resistant to erosion, unlike the soft sedimentary rock. Once the sedimentary rock is worn away, the concretion remains behind.
Tiny concretions known as "blueberries" have also been found on Mars in 2004 and are evidence that water once flowed on the planet.
This article originally appeared on The West Australian.
