What happened to Mars atmosphere? One theory is that the continuous blast of solar particles from the sun – the constant stream of solar wind, coupled with more extreme explosions such as coronal mass ejections – might have been the culprit. Our Mars Atmosphere and Volatile EvolutioN Mission (MAVEN) spacecraft may find out: 1.usa.gov/1uDAY7p This video is an artist's concept showing the transition from an ancient, habitable Mars capable of supporting liquid water on its surface to the cold deser