When you stare up into space, some things stare back. No, not aliens. But these "faces in space" are formations on planets, stars or clouds of gas that look uncannily like visages.
Scroll down for photos.
You've probably heard of the "Man in the Moon" or the face on Mars, but what about the Cookie Monster on Mercury or the eyelike Helix Nebula?
Psychologists have a name for the phenomenon that makes people see faces on inanimate objects. It's called pareidolia, and it's helped people identify patterns in space for millennia -- the constellations are a particularly old example.
They may not be the evidence of alien life that UFOlogists are looking for, but even the most skeptical among us can agree that these faces in space are fascinating fixtures of our universe.
Check out the slideshow below for 10 "faces in space," and next time you're staring out into the sky, give 'em a wink.