Mars may be signaling that the planet is ready for human life.
NASA's mobile robot Curiosity that got sent to Mars in August 2012 is roaming the planet and sending pictures back to Earth.
Three rocks stacked to look like a traffic light were spotted in the corner of a picture by video journalist Joe Smith a few days ago. His job is to review the pictures Curiosity takes to learn more about Mars.
"I saw this one and I thought 'hang on, that looks a bit strange. I think it looks like a traffic light," Smith said on YouTube channel ArtAlien.TV.
He estimates the rock traffic light to be about 12 inches tall.
Although it seems unusual that rocks would coincidentally be stacked in exactly the same shape as an Earthly traffic light, Daily Mail reports that it's highly unlikely this same feature was built by a martian civilization.
The traffic light rocks were spotted just days after a ball shaped rock was discovered on the planet.
The interestingly shaped rocks are giving scientists hope that they will lead them to the answer as to why the water that once flowed on the Red Planet complately evaporated, reports Daily Mail.
Scientists speculate that if they can learn why water dried up on Mars it will help them save Earth.
