The smiling face of a cute-looking teddy bear seems to have been carved into the surface of Mars, waiting for a passing satellite to discover it!

And when the Mars Reconnaissance Orbiter passed over it last month, carrying the most powerful camera ever to travel into the solar system, that's exactly what happened.

Scientists operate the HiRISE (High Resolution Imaging Science Experiment), which has been circling Mars since 2006. Now they have showed us a picture of the face.

"There's a hill with a V-shaped structure (the nose), two craters (the eyes), and a circular pattern (the head)," say the scientists.

The face is about 2km wide. Each one of the features on the face has a possible explanation.

"The circular pattern might be due to the settling of rocks over a buried crater," the scientists say. "Maybe the nose is the vent of a volcano, and the rest could be flows of lava or mud?"

HiRISE takes detailed photos of Mars, helping to map the planet's surface for future missions, either by humans or robots.

Over the last ten years the team has taken photos of avalanches as they were happening. They also discovered dark flows that could be some kind of liquid.

One thing they have not found, however, is the little green men who were once believed to live on the planet!