Three times in a night: NASA observed periodic ultraviolet pulses on Mars.

A NASA spacecraft has observed a pulsed glow from Mars,media reported. There are huge ultraviolet spots in the night sky, which pulsate with incredible regularity — exactly three times a night. The discovery highlights the red planet’s atmospheric processes and circulation patterns. The observations were made by MAVEN, which saw the Martian glow at night, about 70 kilometers above sea level, with the brightest spots about 1,000 kilometers wide.

Three times in a night: NASA observed periodic ultraviolet pulses on Mars.

In these pseudo-color images, green and white areas represent UV intensity, while global images of Mars are added to the digital background.

But what’s most fascinating is the nature of light. According to MAVEN, ultraviolet light only appears in the spring and autumn of Mars, and pulses just three times a night. The show begins after sunset and ends at midnight.

The mechanism that drives the glow is already clear — ultraviolet light from the sun shines on the Martian atmosphere, breaking carbon dioxide and nitrogen into atoms of carbon, oxygen and nitrogen, and then the wind blows them to the night side of the planet, where they begin to sink to the ground. In this process, nitrogen and oxygen atoms combine to form a nitric oxide molecule and in the process release a photon ultraviolet light.

Three times in a night: NASA observed periodic ultraviolet pulses on Mars.

This “night light” effect is well documented on Earth and has been detected on Mars before, but this is the first time it has been seen so rhythmically. Interestingly, scientists saw it circling the planet’s south pole, and the reason behind it is still unclear.

The team is using the light to help map the martian atmosphere circulation and turbulence. In future work, researchers plan to observe the night light from the side by looking at the edge of Mars, which will help people better understand the planet’s wind and seasonal changes.

Three times in a night: NASA observed periodic ultraviolet pulses on Mars.

“MaVEN’s major findings in atmospheric loss and climate change demonstrate the importance of these huge circulation patterns, which transport atmospheric gases around the world and from the surface to the edge of space,” said Sonal Jain, one of the study’s authors. “

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The study has been published in Journal of Geophysical Research.