I dropped red directional light beneath the surface to represent the light of flowing lava in the rifts.
Multi layered vast clouds painted in 3D fluid boxes could give a quite good result (of course in front view).
I think I should use a hell lots o` particles to gain the similar result without using fluids.
I used the old trick, a distorted reflecting surface to gain a more planet shape like landscape.
It is a concave half sphere which reflects the whole scene. The result similar like pictures shot with fisheye optic lenses. Sadly render time multiplies.
Happy new year!