Mystery ball (colored) found on mars

There’s a perfect-looking sphere sitting proudly on a flat rock surface. It’s dusty, but under that dust it appears a little darker than the surrounding rock.

At first glance it looks like an old cannonball or possibly a dirty golf ball. But knowing that Mars is somewhat lacking in the 16th Century battleship and golf cart departments, there was likely another answer. Of course it’s nothing man (or alien)-made, despite what your brain might be telling you. It’s another fascinating rock. Yep, it’s a spherical Mars rock.

http://www.seeker.com/curiosity-finds-a-weird-ball-on-mars-1769110102.html?slide=XHfjHH