The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission arrived and successfully achieved orbit around Mars on September 21st, after a ten-month cruise from Earth. The MAVEN mission is designed to solve the mystery of what happened to the primordial atmosphere of Mars. While abundant evidence suggests that Mars once had a dense atmosphere and liquid water on its surface (perhaps even capable of supporting life?), today it is cold, dry, and barren. Where did the atmosphere go? Either into the surface, or out into space… MAVEN will make all the measurements needed to test the second hypothesis.
Jasper Halekas is the instrument lead for the Solar Wind Ion Analyzer (SWIA) on MAVEN. This instrument will monitor the influx of the solar wind, a supersonic stream of ionized gas (plasma) from the Sun, to the upper atmosphere of Mars. Along with measurements of the Martian atmosphere and the molecules escaping from it, data from SWIA will help determine whether the solar wind could have stripped away the Martian atmosphere.