Large regions of the Martian night sky pulsate in ultraviolet light, according to images from NASA’s MAVEN spacecraft. The results are used to illuminate complex circulation patterns in the Martian atmosphere. The study is published in the Journal of Geophysical Research, Space Physics.
The MAVEN team (Mars Atmosphere and Volatile Evolution, an American artificial satellite for the study of the atmosphere of Mars, which is part of the Mars Scout project) was surprised to find that the atmosphere on Mars pulsates exactly three times per night, and only during spring and autumn on the Red Planet.
The new data also revealed unexpected waves and spirals over the poles in winter and confirmed the results from the Mars Express spacecraft that the night glow was brightest in the polar regions in winter.
MAVEN imagery offers us the first global understanding of atmospheric motions in the middle atmosphere of Mars, a critical region where air currents carry gases between the lower and upper layers.
Nick Schneider of the University of Colorado’s Laboratory of Atmospheric and Space Physics
Clarification occurs where the vertical wind carries gases to higher density areas, accelerating chemical reactions that create nitric oxide and intensify ultraviolet light.
Ultraviolet light comes mainly from an altitude of about 70 km, and the brightest spot is about a thousand kilometers across. It is as bright in ultraviolet light as Earth’s northern lights. Unfortunately, the composition of Mars’ atmosphere means that these bright spots do not emit light in the visible wavelength range that would-be Martian astronauts would see them. It’s a pity: bright spots intensified overhead every night after sunset and drifted across the sky at a speed of 300 km/h.
In the future, the MAVEN team plans to look at the night glow from the side rather than from above using the data obtained by the IUVS. These data will be used to better understand vertical winds and seasonal variations.
The Martian night glow was first detected by SPICAM on the European Space Agency’s Mars Express spacecraft. However, the IUVS is a next-generation tool that is better able to display the night glow repeatedly, detecting patterns and periodic behavior. Many planets, including Earth, have a night glow, but MAVEN is the first mission to collect so many images of another planet’s night glow.