That wasn’t there 12 days ago…
Let’s go back to more of Curiosity’s findings on Mars since there are a ton of them. The picture on the left shows an odd rock formation on the 3528th day of Curiosity’s travels. After shuffling around the red planet, it returned to the same spot only to find that a loose rock lying on the exact spot the rover photographed a mere 12 days ago.

The simplest explanation would be that Curiosity’s tires kicked up sand and rock while moving to and fro, forcing a loose rock to make its way on top of the unusually circular rock formation. This seems to be the more plausible reasoning behind this mysterious photograph, but many think that living beings on Mars may have had something to do with it.