Planet Cloud Shader
The planet cloud shader can be found by selecting the Planet Clouds object and by heading over to the Node Editor.
There, you will see this node group:
BSDF output of clouds
Displacement bump added for realism.
Main color of clouds.
Controls the brightness of the clouds. Less brightness causes more transparent clouds.
Affects the overall scale and size of the clouds.
Adjusts the density and volume of clouds.
Adds random scattering/jittering to clouds. Can be using with Base Scale to simulate wind and cloud movement.
Overall displacement effect. Keep small (around 0.05) for realistic results.