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Looking at time lapses taken from the International Space Station, I discovered that the Earth's atmosphere can glow at night, even when it seems that those pictures were taken far away from auroras.

Here are a few examples :
enter image description here enter image description here

Here is the origin of airglow, according to this Wikipedia article:

Airglow (also called nightglow) is a faint emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this optical phenomenon causes the night sky never to be completely dark, even after the effects of starlight and diffused sunlight from the far side are removed.

Now, my question is about whether or not airglow should be visible (with the naked eye) when looking at Earth's atmosphere from space at night. If not always visible or if the intensity of it varies a lot, is there a way to compute how intense it would be ?

Thank you.

Pop Flamingo
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  • It's probably not visible with naked eye when looking at the brightly lit side of Earth. – SF. Jun 24 '16 at 15:10
  • @SF. You mean that when you are in a completely dark area, it should be visible ? – Pop Flamingo Jun 24 '16 at 15:54
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    I mean, it's fairly dim, and when looking against the glare of Earth day side, it will be completely obscured by daylight. Same as you can't easily see stars from ISS; the glare of earthshine makes your iris to contract so much the sky is pitch black This has more to do with how human eye works, than with presence or absence of the glow. – SF. Jun 24 '16 at 16:12
  • @SF. That's right, also what happens on photos taken on the moon by the way ! There are two things I am still wondering : when the conditions are ok to see it, does it happen that it is not visible due to something else ? And also how exactly does it looks compared to the pictures... as bright ? – Pop Flamingo Jun 24 '16 at 17:00
  • I thought so, that's why I posted as comment, not as answer. I'm afraid someone else will have to answer that. – SF. Jun 24 '16 at 18:02
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    It's a pity this will likely expire without an answer. In thinking about it, i believe the people who can really answer are on the ISS. There are opportunities regularly to ask them questions - but not this week. : / – kim holder Jul 01 '16 at 03:56
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    @kimholder Thank you for reacting to my post ! Yes, I was thinking about AMA on Reddit, do you know about other platforms where it might be possible ? – Pop Flamingo Jul 01 '16 at 06:41
  • I googled 'ask iss astronaut question' and there were links to Twitter, Google +, Gizmodo, and Air and Space magazine links on the first page. Air and Space has a form for asking questions of Tom Jones, a veteran astronaut with 4 shuttle missions. Good luck :) If you get a good answer, please come back and answer yourself so the info will be available for others. – kim holder Jul 01 '16 at 13:42
  • @kimholder Thank you for the link, I'll ask my question and post it here if a get an answer. – Pop Flamingo Jul 02 '16 at 09:46

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The think the glow is not always visible from space. For example: the orbit of the ISS is inclined, but at least twice a year, it should be at the exact opposite side of the Earth relative to the Sun:

ang(le|el)s of light

The atmosphere stretch a bit farther out, but not a lot farther than the ISS. The light should have a hard time bending in such a drastic angle.

As for how bright it is, that must depend a lot on other condition, such as if the Sun is in the sky. Images can probably not reliably used to determine that, as a lens sees thing quite different than the eye. I guess you would have to ask a real cosmonaut for that :)

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