NASA has announced a few unusual findings made by its MAVEN mission, which aims to sample the Martian atmosphere to help us understand its evolution. But by circling the outer edges of the atmosphere, the mission identified some unexpected features of the area above the red planet.
The first, and easiest to understand, are the auroras. Nicknamed the “Christmas Lights” for their appearance last December, the glows were in the ultraviolet range and spanned the entire northern hemisphere of Mars. The source of the energy was electrons accelerated from the sun that were detected by another instrument on MAVEN. Because Mars has no magnetic field, the electrons also reached deep into the atmosphere, creating a light show that was close to the surface relative to Earth’s auroras.
However, the dust is not so easy to explain. It has been a constant, present since MAVEN first entered orbit, and varies between 150 and 300 km above the surface, with particle density increasing at lower altitudes. Like the recent dust plume seen over the planet, it’s not clear what could be lifting the particles off the surface of Mars. “If the dust is coming from the atmosphere, it suggests we’re missing a fundamental process in the Martian atmosphere,” said Laila Andersson of the University of Colorado.
Alternative explanations involve a non-Martian source, such as debris from comets or even Mars’ two small moons. There is also the possibility that it could also be a solar phenomenon.
MAVEN is only four months into its mission, so the red planet may have other surprises in store for its operators.