Realistic Correct Atmosphere V1

Personal Houdini project with the goal of creating a visually correct atmosphere render.

The end result is a shader that correctly simulates the volumetric effect of the atmosphere and Rayleigh scattering at the terminator.
Seen from the side the atmospheres layering with its different colors is also present.
Color and density of the atmospheric layers are set by gradients that are driven by the height of the layer from the ground surface.

All images rendered in Mantra, with a touch of post in Photoshop.