Last fall, Curiosity showed signs of teenage rebellion when it sent back a selfie portrait, presumably to keep its Twitter followers happy. Now NASA's other Martian rovers Opportunity and Spirit have moved onto juvenile delinquency, by sketching out a giant picture of some gentleman's private bits on the pristine Martian surface.
NASA claims that the drawing is actually just tire marks left by the rovers' movements, but I'm guessing that the technician plotting these maneuvers must have a wicked sense of humor.
Opportunity and Spirit have been up there on Mars for about nine years, which makes them just about the right age for such juvenile antics. NASA didn't reveal when the picture was taken, but Spirit has been stuck in the Martian dust for a couple of years, so the image might actually be quite old.