NASA’s MAVEN orbiter has studied how Mars loses atmospheric gas to space since arriving in 2014.
MAVEN stands for Mars Atmosphere and Volatile Evolution. NASA launched the spacecraft on November 18, 2013, and it entered orbit around Mars on September 21, 2014. Its central goal is to understand how the planet’s upper atmosphere interacts with the solar wind and how atmospheric material escapes into space.
Scientists use MAVEN to connect present-day atmospheric loss with Mars’s ancient climate history. Mars once had a thicker atmosphere and surface environments that included stable liquid water, but the planet gradually became colder and drier. Measurements of escaping ions and upper-atmosphere processes help explain part of that transformation.
MAVEN is not a surface rover and does not primarily map the ground. Mars Odyssey and Mars Global Surveyor were also NASA orbiters, while Mars Express is an ESA mission. The spacecraft’s name is commonly written in all capitals because it is an acronym, although “Maven” is also used informally in some contexts.