Astronomers have suspected this for some time, but now they can finally confirm it: at night the sky near the red planet’s poles turns green. The green glow is good news for astronauts, especially those who are afraid of the dark.
According to the researchers, the green glow is so bright that astronauts – as well as spacecraft – near the poles can easily find their way on the dark planet, even at night. You can read it at Nature astronomy.
Light in the dark
First, let’s take a step back. Where does this mysterious green glow come from? The story begins on the day side of Mars, where carbon dioxide (CO2) particles swirling in the atmosphere. When sunlight hits these molecules, they gain so much energy that they collapse. This process produces luminous oxygen atoms. “The wind picks up these oxygen atoms and transports them to the dark side of the planet, where they interact with each other to produce the green glow,” said Laurieanne Surette, one of the scientists who worked on the study.
This is the first time this “night glow” has been observed within the visible light spectrum. This glow has been observed previously, but in infrared light; In 2020, oxygen atoms were detected glowing green for the first time in the atmosphere using… Track the gas orbit (TGO), but on the day side of Mars. It is now known how oxygen atoms continue their journey.
Although nightglow and aurora borealis are two natural phenomena that give off (a lot of) light, there are still some differences. There is also nightglow on Earth, just like on Mars. As explained in this article, nightglow is primarily a (chemical) process that occurs within a planet’s atmosphere. In this way, luminous oxygen atoms are formed in the atmosphere and fall away. With Twilight, it’s really different. For example, aurora borealis are mainly caused by solar flares and coronal mass ejections. This involves the blowing of a large gas bubble saturated with magnetic field lines by the Sun. Then, when a shock wave of solar wind reaches the Earth’s ionosphere, a geomagnetic storm can appear. Do you want to learn more about geomagnetic storms? Then take a look here.
Mars landing is one step away
The discovery of the nightglow on Mars is of great scientific value, because it tells us something about the atmospheric processes occurring on the Red Planet. This makes it possible to conduct better research in places in the Martian atmosphere that are difficult to explore and know how much oxygen is in the atmosphere. It can also say something about exactly how sunlight and solar wind work.
In addition, research is of great importance if we are to eventually land on the Red Planet. Lead researcher Jean-Claude Girard said: “These observations are unexpected and interesting for future missions to Mars.” For example, the density of the atmosphere has a direct effect on how well the parachute works and how well satellites resist the air in the Martian atmosphere.
Finally, when people are finally ready to visit the Red Planet, they can also take advantage of it right away. Because future astronauts take note: If you want to experience a unique light show, go to the North or South Pole of Mars — and don’t forget to take your folding chair with you.
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