[Physics] Orange sky 3.7 billion years ago because there was little oxygen

atmospheric science

PhysOrg quotes Martin VanKranendonk of the University of New South Wales and director of the Australian Center for Astrobiology:

Because the atmosphere had very little oxygen and oxygen is what makes the sky blue, its predominant color would have been orange

Is this correct?

Best Answer

Nope! The blue sky comes from Rayleigh scattering through air, but pretty much any gas whose molecules are decently polarizable will work equally well - it doesn't have to be oxygen. I suspect the guy probably said that there was very little atmosphere and atmosphere is what makes the sky blue (although does it really count as a "sky" if there's no atmosphere?...) and the reporter misunderstood.

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