The satellite in charge of monitoring the atmosphere of Mars has detected bright green oxygen and it is the first time that this emission has been seen on a planet other than Earth. Bright oxygen is produced on our planet during the polar auroras when energetic electrons from interplanetary space hit the upper atmosphere . This oxygen- powered light emission gives the polar auroras their popular and beautiful shade of green. However, aurora is one of the forms that illuminate planetary atmospheres , as they constantly shine during the day and night as sunlight interacts with atoms and molecules within the atmosphere.
On Earth , the greenish glow can best be seen from an ‘edge’ perspective, as shown in images taken by astronauts from the International Space Station. “One of the brightest emissions observed on Earth comes from the night glow. More specifically, from oxygen atoms emitting a particular wavelength of light that has never been seen around another planet, ” says Jean-Claude Gérard, from the University of Liege, Belgium, and lead author of the new study . ” However, this emission is expected to exist on Mars for about 40 years , and, thanks to TGO, we have found it. ”
“Previous observations had not captured any kind of green glow on Mars , so we decided to reorient the nadir UVIS channel to target the ‘edge’ of Mars, similar to the perspective seen in images of Earth taken from the ISS. ” adds co-author Ann Carine Vandaele of the Institut Royal d’Aéronomie Spatiale de Belgique, Belgium, and NOMAD principal investigator. Studying the brightness of planetary atmospheres can provide a wealth of information on atmospheric composition and dynamics, and reveal how energy is deposited by sunlight.