NASA/JPL-Caltech/MSSS/Red circle by Amanda Kooser/CNET

Seriously, people, we've been through this before. There are no fish, cannonballs, thigh bones, spoons or crab monsters on Mars. And there are no boots or robot legs. Just rocks. Lots and lots of rocks.

I was just innocently browsing Google search trends when I saw folks getting excited about signs of extraterrestrial life on Mars as spotted by NASA's Curiosity rover. The frenzy seems to trace to a raw image snapped by the rover's mast camera in early August.

It's a cool image, as just about any photo from Mars is. It shows a close-up view of the ground near the rover, including a collection of small rocks scattered about. One of them has a distinctly boot-like shape to it. A popular UFO blog suggests this is from the leg of an ancient robot. It's not.

The boot-shaped object is a rock. Take a closer look and you can see the layers and that it's likely two very small rocks snuggled up next to each other with a crack dividing them.

This is really about pareidolia, the human tendency to assign meaning to random shapes. This is why we can imagine seeing dragons in clouds, a roaring T. rex in a lightning strike or alien faces on Mars.

I have one more damning piece of evidence to support my rock assertion. Curiosity just drilled a fresh hole on Mars to get a better look at the local geology. An image from Aug. 4 shows this drill hole.

Enlarge Image NASA/JPL-Caltech/Red text by Amanda Kooser/CNET

Take a look at the photo and then look up just above it to the left. That's the same boot-shaped rock. It's minuscule. If that's a robot leg, then it's from the tiniest robot in the universe.

I love seeing Mars rocks that look like familiar Earth objects. It's a fun game to play, a crossing over between science, space exploration and entertainment. But they're still rocks and not signs of an alien civilization.

Instead, let's get excited about Curiosity reaching its seventh anniversary of landing on Mars. It's been on an incredible journey of exploration and the rover is still going strong, overcoming computer glitches and damaged wheels along the way. Well, maybe Curiosity could see about trying that robot boot on for size.