European Space Agency orbiter and Roscosmos The Trace Gas Orbiter (TGO) has recorded visible nightglow on Mars for the first time. That is, people can see it with the naked eye. An international team of scientists watched through TGO cameras as the Red Planet’s atmosphere glows green. According to them, this glow is so bright that it can light the way on a dark night for rovers or future astronauts arriving on Mars. The study of the phenomenon was published in the journal Nature Astronomy.

Similar glows occur on Earth, experts explain. However, these are not polar (northern) lights, although they may look similar. The effect is called day or night airglow, depending on the time of occurrence. And it happens for other reasons: if auroras are the result of the collision of charged particles from the Sun with the Earth’s magnetic field, then auroras are the combination of two oxygen atoms to form an oxygen molecule.

Astrophysicists assumed 40 years ago that such night glows could also occur on Mars. But until now they have never been observed in the visible spectrum. About ten years ago, another orbiter discovered this phenomenon in the infrared spectrum. And three years ago I managed to see him, but in daylight. And only now, using TGO equipment, the phenomenon was observed for the first time at night.

Scientists from the Laboratory of Atmospheric Physics at the University of Liege (Belgium) explained that oxygen atoms “travel.” They form on the dayside of Mars when sunlight causes them to break apart. And then they migrate to the night side, where they become inaccessible to the Sun, so they unite again and begin to emit light at altitudes of approximately 40-60 kilometers in the Martian atmosphere.

“The intensity of the night glow in the polar regions of Mars is such that simple and relatively inexpensive instruments in its orbit can map and monitor atmospheric flows. These new observations are interesting for future trips to the Red Planet,” explains planetary scientist from the University of Liege Jean-Claude Gérard.

“The radiation is intense enough to be observed by future astronauts during the polar night in orbit or from the Martian surface.”

The team said that the Trace Gas Orbiter mission will continue to study the night glow of Mars. It will help to obtain a more detailed understanding of the processes in the Martian atmosphere. In particular, to study the composition and dynamics of layers at an altitude of 40-80 kilometers – where satellite measurements are no longer available.

Information about the density of the atmosphere and an understanding of its properties are important in the design of future spacecraft that will have to land on the surface. And also for the development of orbital satellites and parachutes for lowering payloads to Mars.