- It doesn't get more classic than this. The Viking 1 spacecraft spotted this "Face on Mars" in 1976. Since then it's been featured in movies and TV shows. When the Mars Global Surveyor flew over and snapped sharper photos in 1998, the face was seen for what it really is: simply a mesa.
- NASA's Curiosity rover captured this cutie on Mars in January 2013. The rock does bear a remarkable likeness to an iguana -- it's got a tail, dewlap and even an "eye." But again, this is just a rock.
- When the Mars rover Spirit captured this image of a human-like figure in 2007, alien enthusiasts hoped it might finally be a sign of alien life on the red planet. Scientists' verdict? Rock.
The "Mars rat" was found in a March 2013 image from the Curiosity rover. The rat took the Internet by storm -- and even got its own Twitter account. So, rock or tech-savvy rat?... It's just. A rock.
- Spooky! This skull-like object was spotted in an image taken by the rover Spirit in 2006. Similar "skulls" have been spotted in subsequent rover images -- including a bird and a T. rex. Even an "alien's skull" was spotted. The verdict? ALL ROCKS.