Heh, nitpick city. Even if Mars had an atmosphere as thick as Earth's, at the distance from the planet in the pic it wouldn't show at all at this scale. Jupiter's atmosphere is around a hundred miles deep and it doesn't show in even quite close views of the 'edge' of the planet. The implausibly-large-atmosphere-halo is an aspect of contemporary space/fantasy art (mostly non-professional). It must be rare in earlier works because I don't remember seeing any. I just did a random scan of my not insubstantial collection of space art books and didn't spot one example. From a purely personal point of view it bugs the hell out of me, interfering with the suspension of disbelief. But art is art and people should do as they wish.