On Earth, this happens in the form of clocks at the poles of the planet, but this is the first time this kind of glow has been seen around another planet.
The Earth’s polar green glow occurs when electrons from space collide with our upper atmosphere, but the Earth’s and Mars’ atmospheres glow both during the day and at night thanks to sunlight. At night, a glow is created when the molecules in the dissolved atmosphere return together. During the day, glare occurs when sunlight shakes atmospheric molecules and atoms such as nitrogen and oxygen.
Astronauts at the International Space Station have the best view of the Earth’s faint green night glow, because their perspective is “edge”, which means they can see it from a angle that makes the glow more visible.
This is because our planet has a bright surface, which can flood this dim glow. The same goes for other planets, which is why the detection of green light around Mars is so fascinating.
“One of the brightest emissions on Earth comes from night glow. In particular, from oxygen atoms that emit a certain wavelength of light that has never been seen on another planet,” said Jean-Claude Gérard, lead author of the study. and astronomer and professor at the University of Liège in Belgium, in a statement.
“However, this show is expected to be on Mars for about 40 years – and, thanks to [Trace Gas Orbiter]we found it. “
ExoMars Trace Gas Orbiter orbited Mars around October 2016. Some of its orbiting instruments, collectively referred to as NOMAD (Nadir and Occultation for Mars Discovery), were spotted on the surface of Mars during the orbit. These instruments include the ultraviolet and visible spectrometer or UVIS.
Hoping to find a green glow, the instruments were oriented to take a “tip” view of Mars and scan at different altitudes twice per orbit between April 24 and December 1, 2019. The altitudes ranged from 20 to 400 kilometers (12.4). up to 249 miles) from the surface of the planet.
The indicative green glow was found in all the data collected during this period – and an impressive orbit for the orbit, given that the atmosphere of Mars during the day shines much brighter than the night and makes it green. glare more difficult to detect, the researchers said.
“The emissions were stronger at an altitude of about 80 kilometers and varies depending on the changing distance between Mars and the Sun, “said Ann Carine Vandaele, study author and lead researcher at NOMAD at the Institut Royal d’Aéronomie Spatiale de Belgique in Belgium, in a statement.
What’s in a green glow?
Comparing the two planets, the researchers found that the green glow of Mars is different from that of Earth.
“We modeled this broadcast and found that it is produced as carbon dioxide or CO2, [and] it breaks down into its components: carbon monoxide and oxygen, “Gérard said. We have seen the resulting oxygen atoms glow in both visible and ultraviolet light. “
Although this agrees with the theoretical models that suggest that Mars will have this glow, it is much more powerful than the visible emissions created by the Earth.
“This suggests that we need to learn more about how oxygen individuals behave, which is extremely important for understanding individual and quantum physics,” Gérard said.
Observing bright planetary atmospheres can reveal the composition and energy gained from both sunlight and the sun’s wind, or from a stream of charged particles moving in the solar system.
This is also crucial for understanding the hours. By studying the green glow of Mars, researchers can understand the structure of this layer in the planet’s atmosphere, better understand its altitude range and even observe any changes in the reaction to the sun.