Watch: Mars got a weird nightglow in its atmosphere that pulses three times a night. The Red Planet is wonderfully weird
You know, I wasn’t even aware of Mars’ nightglow in its atmosphere. But, I am now! Additionally, I also now know that motherfucker pulses three times a night. Awesome.
The arrival of spring and fall on Earth is marked by milder temperatures and the respective sprouting and shedding of leaves. Spring and fall on Mars, in contrast, is signaled by the Martian atmosphere weirdly emitting exactly three pulses of ultraviolet light every night, according to a new study.
These clockwork “nightglow” pulses on Mars during equinoctial seasons reveal hidden circulation patterns in the Martian atmosphere, which is about 100 times thinner than Earth’s skies.
Scientists led by Nick Schneider, a planetary scientist at the University of Colorado’s Laboratory for Atmospheric and Space Physics, have been observing the nightside of the red planet with NASA’s Mars Atmosphere and Volatile Evolution (MAVEN), an orbiter that arrived at Mars in 2014.
Schneider and his colleagues used MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument to take a closer look at the middle of the Martian atmosphere, which is about 70 kilometers (approximately 40 miles) above the surface.
In addition to measuring the nighttime pulses, the team reports the discovery of a polar sky spiral and “a remarkably bright spot” at the equator, according to a study published on Wednesday in the Journal of Geophysical Research: Space Physics.
“MAVEN’s images offer our first global insights into atmospheric motions in Mars’ middle atmosphere, a critical region where air currents carry gases between the lowest and highest layers,” said Schneider in a statement.
The team was able to probe Mars’ global circulation patterns by focusing on chemical reactions that are driven by the shift from day to night. Carbon dioxide and nitrogen molecules in the atmosphere get split up into their constituent elements by sunlight during the day. When night falls, nitrogen and oxygen molecules descend into the middle atmosphere, where they hook up to create nitric oxide—a union that releases ultraviolet light.
The pulses are caused by the unique pattern of atmospheric winds during Martian spring and fall. Shortly after the sun sets, gusts from higher layers of the atmosphere rush into the middle skies, catalyzing a very bright ultraviolet pulse, followed by two dimmer ones. This glow is particularly evident at “an unusually bright spot on Mars’ nightside” at the equator, according to the study.
The Martian atmosphere circulates more globally and symmetrically near the equinoxes, according to the study, in contrast to airflow patterns at the solstices, which tend to cluster at the poles.
The team plans to continue probing the mysterious dynamics of the middle atmosphere, including the eerie ultraviolet nightglow, to refine our models of the Martian skies.
“Further study of discrepancies between the model and observations offers opportunities to improve our understanding of chemical and transport processes controlling the emission,” the team concluded in the study.