It's only been a day since skywatchers around the world were treated to a particularly energetic display of auroras because of an intense geomagnetic storm, but researchers have announced that NASA's MAVEN mission has observed auroras on Mars as well, only they are in energetic ultraviolet wavelengths instead of visible light.
The auroras were detected by MAVEN's Imaging Ultraviolet Spectrograph instrument five days before Christmas causing scientists to nickname these ultraviolet auroras "Christmas Lights." These lights were observed across the planet's mid-northern latitudes are are the result of the atmosphere of Mars interacting directly with the solar wind.
Auroras on Earth are typically only observed at altitudes of 50 to 200 miles (80 to 300 kilometers) and sometimes even higher. However, on Mars the atmospheric displays were found to be much lower indicating higher levels of energy.
"What's especially surprising about the aurora we saw is how deep in the atmosphere it occurs - much deeper than at Earth or elsewhere on Mars," said Arnaud Stiepen, IUVS team member at the University of Colorado. "The electrons producing it must be really energetic."
The light show on Mars wouldn't be all that dramatic to a human observer, though. Without the abundant amounts of oxygen and nitrogen in the thin atmosphere of Mars the Martian aurora would be a dim blue glow at best and might not be in the visible sprectrum of humans at all.
This isn't the first time auroras have been spotted on the Red Planet. In 2004, observations with ESA's Mars Express were actually the first time that the aurora phenomenon had been detected. The observations were made with the spacecraft's SPICAM ultraviolet spectrometer and found that the auroras on Mars are not like those found anywhere else in the Solar System. They are generated by particle interactions with very localized magnetic field emissions, rather than a globally generated one such as the auroras generated here on Earth.
In addition to the auroras, MAVEN also detected diffuse but widespread dust clous located surprisingly high in the Martian atmosphere at about 93 miles to 186 miles (150 to 300 kilometers). Scientists do not yet understand what process is delivering the dust so high or if this phenomenon is a permanent or temporary feature.
While the auroras discovering isn't a unique one, they still represent yet another step in the process of scientists understanding the Red Planet and how it interacts with the Solar System in which it lives.
