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When you look up right after dusk or before dawn, you are very likely to see passing satellites passing overhead, still illuminated by the sun and reflecting daylight towards you.

All theses appear to be yellowish white.

Why is that so? Is it because they all average out to a similar reflective colour?

What if I sent a huge pink reflective balloon; would it appear pink?

uhoh
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Antzi
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    The experiment should be done and live broadcast. I'm pretty sure in the future we'll be seeing a variety of space-art up there. – uhoh Jun 09 '17 at 06:39
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    @uhoh You'll like this project http://asia.nikkei.com/Business/Companies/On-demand-shooting-stars-Japanese-startup-dreams-big – Antzi Jun 09 '17 at 07:00
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    I laughed out loud, then said "of course! where else?" Then I asked a follow-up question. Thanks for this! – uhoh Jun 09 '17 at 07:20

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It's possible that most satellites are similar in color, but an additional likely reason for this is for the following physiological fact. The eye has rod cells and cone cells. The rod cells see only black and white, and are extremely sensitive. The cone cells see color, and are much less sensitive. When you look at something that isn't very bright, the result is that you can't see it in color. This is why you can't see color clearly at night when the light is dim. Most satellites are not that bright, comparable to maybe a 3rd magnitude star I would guess. That isn't enough light to see color very clearly.

You can see this effect very clearly when you look at a long-exposure photograph of the night sky, or when you look at stars through a telescope with a large aperture. The colors of the stars are much clearer than with the naked eye.

  • It's likely someone has already put a low dispersion (e.g. 100 groove/mm) grating over their DSLR and recorded a spectrum of a satellite (dispersion perpendicular to path of satellite. If not I hope someone does it and posts here! https://youtu.be/Fv5fFSacVO8 and http://www.fieldtestedsystems.com/starspectra/ and http://www.fieldtestedsystems.com/poster/ – uhoh Jun 09 '17 at 06:42
  • I've asked a follow-up question. – uhoh Jun 09 '17 at 06:58