Observations were made by the spacecraft Mars Atmosphere and Volatile EvolutioN (MAVEN), which studies the Red planet from orbit. Sputnik saw the glow at night at an altitude of about 70 kilometers, the brightest spot has a width of about 1000 kilometers. MAVEN data showed that the pulsation occurs only during the spring and fall seasons. But the process begins immediately after sunset and ends at midnight.
The glow occurs when ultraviolet radiation from the sun penetrates the Martian atmosphere and breaks down carbon dioxide and dinitrogen atoms of carbon, oxygen and nitrogen. Then the winds carry these atoms on the night side of the planet, where they begin to sink towards the surface. The atoms of nitrogen and oxygen combine to form nitric oxide, and emitting UV light.
This effect of “night glow” is well-known on Earth, and has previously been recorded on Mars, but scientists say that for the first time this process, there is such rhythm. Interestingly, the glow moving to the South pole of the planet, why is this happening, scientists still don’t know.
Zach Milbi from the Laboratory for atmospheric and space physics comments: “unfortunately, due to a different composition in the atmosphere of Mars does not occur in visible rays, so that this radiance will not be able to see and future astronauts. A pity: the bright spots could open up on them every night after sunset and move through the sky at speeds of 300 kilometers per hour.”
The command uses the information about these glows to map the circulations of the Martian atmosphere. This should help to improve understanding of wind and seasonal changes of the planet.