NASA’s Mars rover, Mars and Atmosphere Evolutio N (MAVEN), has successfully captured a pulsed glow from Mars. Huge ultraviolet spots appear on Mars at night and are incredibly regular, happens to be three times a night. It is understood that in the eyes of scientists, this discovery highlights the Martian atmospheric processes and circulation patterns.
The brightest spot in the pulsed glow found by the MAVEN detector is reported to be about 1,000 kilometers (600 miles) wide. In the composite image, green and white areas represent the intensity of ultraviolet light, while the global image of Mars is added to the digital background. The most surprising thing is the seasonality of the pulse. According to MAVEN, ULTRAVIOLET pulses occur only in the spring and autumn of Mars, and occur exactly three times a night, starting after sunset and ending at midnight.
Scientists have learned about the mechanism behind this unique pulse on Mars: ultraviolet light from the sun hits the Martian atmosphere, breaking down carbon dioxide and nitrogen into atoms of carbon, oxygen and nitrogen. The wind then blows these atoms to the “night side” of Mars, where they begin to sink to the surface. In this process, nitrogen atoms and oxygen atoms combine to form a nitric oxide molecule, and in the process release seofs of ultraviolet light.
In fact, this “night glow” phenomenon is not uncommon and has previously been detected on Mars, but the maVEN discovery is the first time such a regular pulse has been seen.
The team is using this seasonal ultraviolet pulse to help map the circulation and turbulence of the Martian atmosphere. They also plan to look at the night glow from the side in future work by looking at the edge of Mars, which will help people better understand wind and seasonal changes.
“The MAVEN findings demonstrate the importance of these huge circulation patterns, which carry atmospheric gas from the surface of Mars to the edge of space,” said Sonal Jain, one of the study’s authors.
The study was published in the Journal of Geophysical Research.