APOD: Dark Dunes on Mars (Horizontally... (2016 Jul 20)

[Chris Peterson]

May I ask, is that blue sky in the background of this image? Is that normal for Mars? I though our blue sky was the result of the wavelengths of light that can get through our atmosphere? Doesn't Mars have little or no atmosphere?

Mars has sufficient atmosphere to produce a sky which is lit by scattered light. It is probably on the pink side in most cases, but blue is possible as well. Images tend to be processed in different ways to emphasize different things, so are not generally reliable for assessing sky color.