25 November 2023

Green "nightglow" in the skies of Mars caused by oxygen (!!)


The embedded image is of earth's nightglow, but the same process occurs on Mars, for rather unexpected reasons.
The international scientific team was intrigued by a previous discovery made using Mars Express, which observed the nightglow in infrared wavelengths a decade ago. The Trace Gas Orbiter followed up by detecting glowing green oxygen atoms high above the dayside of Mars in 2020 – the first time that this dayglow emission was seen around a planet other than Earth...

Under clear skies, the glow could be bright enough for humans to see by and for rovers to navigate in the dark nights. Nightglow is also observed on Earth. On Mars, it was something expected, yet never observed in visible light until now...

The atmospheric nightglow occurs when two oxygen atoms combine to form an oxygen molecule, about 50 km (~30 miles) above the planetary surface.

The oxygen atoms have been on a journey: they form on Mars’s dayside when sunlight gives energy to carbon dioxide molecules, making them split apart. When the oxygen atoms migrate to the night side and stop being excited by the Sun, they regroup and emit light at lower altitudes.

Oxygen on Mars.  You learn something every day.   

5 comments:

  1. According to NASA, on Mars, oxygen is only 0.13%, compared to 21% in Earth's atmosphere. That is before the "nightglow" discovery.

    p.s. any special reason for a capital "I" in the 'nIghtglow' of the blog title?

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  2. Can we get Elon there soon enough to be of use to humanity? Next month would be just awesome. I'll donate the first potatoe.

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  3. In the middle 1980s I was teaching in a little alternative school out in the woods. One of the subjects was electricity, and one of the electric experiments was to use a vacuum pump made of a compressor cut out of an old refrigerator, and use neon sign transformers and Tesla coils for high voltage. I tried different gases in the bottles: normal air, water vapor, helium, carbon dioxide. Air (nitrogen and oxygen) rarified and shot through with electricity glowed varying shades approaching white depending on how much power was used, but mostly blue. Helium gave reddish light. /Carbon dioxide/ was always green. Evaporated water was just like normal air, but that might have been because of the low quality of the homemade equipment-- it might have simply been normal air.

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  4. RED PLANET DAY
    Every year on November 28th, Red Planet Day commemorates the launch of Spacecraft Mariner 4. It’s also a day to learn more about Mars, which is referred to as the red planet

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