This curiosity, currently making its way around the web, snapped by one of the cameras of the Curiosity rover on the surface of the planet Mars has been dubbed the Mars rodent. From this vantage point -- the only one we're offered by the rover -- it does resemble a guinea pig as you'd find in any Earthly pet store.
Or is it more likely that this is a remarkable optical illusion, a rock whose shape fools us into seeing a furry little critter with a nose, eye, and possibly a front foot? Go see it in the Mars Gallery.
What do you think?