Monday marks one year since NASA’s Mars Atmosphere and Volatile Evolution mission (MAVEN) entered orbit around our planetary neighbor. The goal of the $671 million mission is to investigate the planet’s upper atmosphere in hopes that it may hold clues about how Mars transitioned from a wet world with a thick atmosphere to a desert world with a thin one.

Launched on November 18, 2013, the spacecraft traveled for about ten months and more than 400 million miles before it reached the Red Planet. Since then, MAVEN has had a full year, including among its accomplishments the first up-close observation of a comet flying by Mars, and four deep-dip campaigns to collect information from the lower, denser portions of the Martian upper atmosphere.

A year later, here are some highlights from MAVEN’s mission so far.