Today, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission — sent to Mars to explore its upper atmosphere, ionosphere and interactions with the Sun and solar wind — celebrates 1,000 Earth days in orbit around the Red Planet. This artist’s concept shows MAVEN in orbit around Mars, with a fanciful image of Earth in the background. Image credit: NASA / GSFC. MAVEN, part of NASA’s Mars Scout program, launched on November 18,...