I’ve read that a lunar eclipse is what makes the moon appear red in the sky, because only light of certain wave lengths passing through our atmosphere. Would it also be red when viewed not from earth? It would still be the same light reaching it but bouncing back to our eyes not through the atmosphere. I’m not sure I’ve fully understood, I’d very much appreciate a science lesson. Thanks
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Yep. The red light is what hits the moon once it passed through our atmosphere. So the moon will appear red even when viewed from space.
[This is the eclipse](https://c.tadst.com/gfx/1200×675/total-lunar-eclipse-blood-moon.png?1) and this is [how it looks from the Moon](https://i.insider.com/55f581dbbd86ef1e008b9f11?width=1000&format=jpeg&auto=webp), and the light that reaches the Moon is red because our sky is blue (that is, the air scatters the blue color up and down (to the surface) and sideways, basically preventing it from continuing on towards the Moon, so only the more reddish colors continue past the atmosphere to hit the Moon).
[See for yourself](https://petapixel.com/2022/05/17/astronaut-captures-lunar-eclipse-from-the-international-space-station/). Short answer is no, it’s basically brown.
Great question! During a lunar eclipse, the moon appears red when viewed from Earth because the Earth’s atmosphere filters out most of the sunlight that would normally be reflected off the moon’s surface. This leaves only the red wavelengths of light, which are able to pass through the Earth’s atmosphere more easily due to their longer wavelengths.
However, when the moon is viewed from space, it would not appear red during a lunar eclipse. This is because there is no atmosphere around the moon to filter out the sunlight, so all wavelengths of light would be reflected back to an observer. This means that the moon would appear its normal white or gray color when viewed from space during a lunar eclipse.
Broadly, yes. Think about it. A lunar eclipse is the Earth’s shadow blocking the direct path of light from the Sun to the Moon. Yet we, on Earth, see red light coming from it. So what’s that light?
We know that the Moon doesn’t visibly glow in its own right, and starlight is way too weak to illuminate it. That leaves sunlight. How? The short answer is, it’s light that got bent by the Earth’s atmosphere. But the atmosphere bends different colours to different degrees – and most of the light that actually gets to the Moon is red ([nice NASA diagram here](https://www.hindustantimes.com/science/nasa-explains-why-the-moon-turns-red-during-a-lunar-eclipse-watch-101667616724643.html)).
So, basically, during a lunar eclipse, the Moon is still being lit by sunlight, and that light is predominantly red. Which means that, if you’re in a position to see a significant amount of that light after it’s reflected off the Moon, a red tinge is what you can expect to see – whether you’re on Earth or in space.
(In space, if that diagram is reasonably accurate, you’ll potentially start seeing more yellow light as well if you’re further away from the centre line to the Earth’s shadow, because the parts of the Moon’s surface directly facing you are increasingly being illuminated by light of other wavelengths. So the precise colour will vary according to where you are. But it’s still going to be dominated by light from the red end of the spectrum.)
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