NASA scientists were surprised to see a "mysterious rock" suddenly “appear” in front of the Mars Rover six days ago.

The same patch of Martian landscape, imaged 12 Martian days apart.You can see the rock in the images above. The image on the left shows the area in front of Opportunity on Sol 3528. A comparison of two raw Pancam photographs from sols 3528 and 3540 of Opportunity's mission (a sol is a Martian day). Notice the "jelly doughnut"-sized rock in the center of the photograph to the right. Minor adjustments for brightness and contrast.The image to the right was taken 12 Martian days later and is almost identical—except for a rock the size of a jelly doughnut that had suddenly appeared.
The Opportunity rover was conducting a thorough analysis report in the Cape Darby area of the Red Planet when the machine was put on hold and suddenly filmed this materialized Mars mystery rock. The stone was not in any prior images, and there is no evidence of anything (or anyone) placing it there. The foreign object is being called the code name “Pinnacle Island” and is expected to be part of some major scientific study and thought-making in the coming weeks.
“Most of all, NASA wants to figure out how the rock got there in the first place. Two theories have been estimated to determine the arrival of this unexpected surperise. Either the Opportunity somehow managed to turn up the stone while it was moving over Mars’s surface, or the rock was blown right out of the ground by a meteorite impact and happened to land next to the rover. It is mostly thought that the rover is to blame for the rock’s sudden appearance, although NASA admits that is just a guess. Apparently, the Opportunity’s front right steering has become out of commission, and that could have somehow caused the large stone to become dislodged and caused it to land in the position it is showing up in.”