Earth seen from space - cloud volumetric


Hi everyone,

I hope that someone could help me. I try to make an image of the earth seen from space but but i can’t get the result i want.
i really get stuck for the cloud. I can’t get a look volumetric. I tried with a displacement map but the result is not what I would like.

I wish it looked like that kind of visual

or the planet that we see from space at the beginning of the film Avatar

I use 3ds max phoenixFD and vray but but if you suggest another software, i take.

Thank you in advance.

PS : Excuse my English ^^