NASA’s Curiosity rover has been exploring the surface of Mars since it landed on the red planet three years ago.
Since then, Curiosity has beamed home incredible images of Mars, redefining how humans understand the red planet’s complicated geology and past.
The car-sized spacecraft has already discovered that Mars‘ Gale Crater — the rover’s landing area — was once a wet, warm place that could have hosted microbial life millions of years ago. And Curiosity isn’t done making discoveries yet.
The rover is now checking out the lower elevations of Mount Sharp, its ultimate destination when it landed on Aug. 5, 2012, and NASA says the Mars explorer is in good health as it enters its fourth year on the rusty surface of the red planet.
Check out some of our favorite images of Mars taken during Curiosity’s first three years roving the Martian surface.