Where Did Mars's Atmosphere Go?
MAVEN was the first mission devoted to Mars's upper atmosphere. It found that the solar wind strips about 100 grams of gas from Mars every second, and much more during solar storms. Over billions of years this kind of loss helped turn a once warmer, wetter planet into the cold desert seen today.
Science and Relay
MAVEN orbited Mars from 21 September 2014, more than a decade beyond its one-year prime mission. Its ultraviolet spectrograph mapped the make-up of the upper atmosphere, and its radio relayed data from the Curiosity and Perseverance rovers to Earth.
Loss of Signal
On 6 December 2025 MAVEN went silent after passing behind Mars. Fragments of data suggested it was spinning, and a NASA review board found that the spin had drained its batteries and cut power to its radio. With no way to recover it, NASA declared the mission over on 3 June 2026. Other orbiters took over its relay work.