It wasn't there... and then it was, about the size of a jelly doughnut, too large to be wind-blown:
Sudden changes are often interesting, and NASA did its usual thing, taking photos and figuring out what was going on.
That wasn't enough for one Rhawn Joseph, who immediately smelled a conspiracy designed to suppress this obvious sign of Martian life. “The refusal to take close up photos from various angles, the refusal to take microscopic images of the specimen, the refusal to release high resolution photos, is inexplicable, recklessly negligent, and bizarre,” he wrote. He then filed a lawsuit to force NASA to reveal what it knew, and to do more research. http://abcnews.go.com/Technology/nasa-sued-failing-investigate-martian-jelly-donut-rock/story?id=22335788
Not trivially, Rhawn Joseph has written several books on "biologic UFOs," and 9/11.
(Note to self: Never buy or read any book by Rhawn Joseph.)
NASA went about its business in the normal way and at the normal pace, taking thousands of images and looking closely at the rock. because the rock's upper surface looked fresh and unweathered, scientists quickly floated the theory that one of Curiosity's wheels had dislodged a loose piece of rock, causing it to flip over and skitter across the surface for a short distance.
Guess what? That's exactly what it was. Once they moved the rover, they could see where the rock came from. The rover's tread marks are nearby, too. The jelly doughnut rock's to the lower left in this photo; the hole it came from is in the upper center.
If only all half-baked conspiracy theories could be so easily quashed.
Full story: http://tinyurl.com/mg5tdh6