Earth has blue skies and red sunsets. Mars has red skies and blue sunsets.
The sky on Earth is blue because gas molecules reflect blue light. Earth sunsets look red because all the blue light has already been filtered out.
The sky on Mars is red because dust particles reflect red light. Martian sunsets look blue because all the red light has already been filtered out.
Two planets. Opposite skies.
@InvaderXan Yup~ Rayleigh scattering is one hell of a thing (or barely a thing, as far as Mars' atmosphere around midday goes - it's just too thin for it to show over the dust)
