User talk:Nickwogan/sandbox pale blue dot

Why is the Earth a Pale Blue Dot? Earth is a blue dot mainly because of how light scatters in its atmosphere (Rayleigh scattering). In Earth’s atmosphere, short wavelength visible light is scattered much more than long wavelength visible light. Therefore blue light (~440 nm) is scattered in Earth’s atmosphere to a greater extent than other visible sunlight (380 - 750 nm). [You might consider another sentence here about how the Sun's blackbody spectrum is peaked in the green, so there is more blue light to scatter than purple light, which is why we have blue and not purple skies.] The ocean contributes a small amount to Earth’s blueness, but scattering is the main contributor.[1] Earth is a pale blue dot rather than dark blue because of clouds, which reflect all visible sunlight. The combination of white light reflected by clouds and the scattering of blue light is why Earth is pale blue when viewed from space.

Earth’s reflectance spectrum from the far-UV through the visible to the near-Infrared is unlike any observed uninhabitable [I really don't like this; every planet is uninhabited, is this saying there are planets with sufficient oxygen that we've seen? I think you could eliminate this and the next sentence and have the last one stand on its own] planet and is partially due to biology.[2] Rayleigh scattering can only occur in an atmosphere that is transparent to visible light. Earth’s plentiful atmospheric O2, which comes from photosynthetic biology, causes the atmosphere to be transparent to visible light which allows for substantial Rayleigh scattering.

[Overall, I tried to eliminate some of the redundancy, but that is probably making it harder to read.]

Atmospheric Anna (talk) 17:27, 11 June 2019 (UTC)