Mars has auroras, but they do not work like the ones on Earth. On our planet, the magnetic field funnels solar particles toward the poles, creating ribbons of green and red. On Mars, there is no global magnetic field to guide those particles. Yet the sky still glows.
A planet without a magnetic shield
NASA’s MAVEN spacecraft has been orbiting Mars since 2014, studying the thin upper atmosphere. Scientists using MAVEN data have now pieced together how Martian auroras form. The key is not a single planetary field but many small, localized magnetic fields. These patches are remnants of ancient crustal magnetism, frozen into certain regions of the Martian surface. When solar storms hit, energetic particles from the sun stream toward Mars. Instead of being deflected at a distance, they crash directly into the atmosphere. Where they encounter one of those crustal magnetic patches, the particles get funneled downward, exciting gas molecules and producing ultraviolet light. The result is an aurora, but one that is diffuse, patchy, and invisible to the human eye. It glows only in ultraviolet wavelengths.
Why local scientists took notice
The research was led by scientists at the University of Colorado Boulder and NASA’s Goddard Space Flight Center in the United States. They analyzed data from multiple solar events to confirm the pattern. For the MAVEN team, this matters because auroras reveal how the solar wind interacts with Mars today. That interaction slowly strips gas from the atmosphere, a process that may have turned a once wet and warm planet into the cold desert it is now. Understanding the aurora helps scientists trace where and how that stripping happens. For the wider public, the finding is a reminder that auroras are not unique to Earth. They are a planetary phenomenon, shaped by whatever magnetic environment a world happens to have.
A different kind of sky show
Mars will never host the kind of aurora displays seen in Norway or Canada. Its auroras are spotty, ultraviolet, and tied to ancient magnetic scars in the ground. But they are still auroras. The MAVEN mission has now shown that even a world without a protective magnetic bubble can put on a light show. It just takes a different set of rules.
