Mars, once thought to be a static, dusty landscape, is ever changing. It wasn't until NASA's Mars Reconnaissance Orbiter (MRO) showed up that we observed shifting dunes, seasons coming and going, and dust devils swirling across the planet. The spacecraft recently marked its 15th anniversary in orbit around our neighboring world, where it has used a suite of four science instruments and three cameras to catalogue a diverse array of geologic features. “Before we had never had enough resolution over a long-enough period to see changes on the surface,” says Richard Zurek, MRO's project scientist at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “Today we can see that Mars is dynamic.”