How to create earth's atmosphere

i was thinking about making a map where u can go outerspace just like spacebuild, but i’m not creating planets, only 2 divided areas.

the problem is, how do i create the atmosphere part? how do i create clouds? smoke effects? would lag alot
i like how u would burn when ur falling from space to earth,

and also, is it possible to have 2 different skybox in two different certain areas?

bump
i want to know how to blend sky>starfield

Have layered func_brushes with sky_fake_white and colored blue with varying degrees of opacity at different heights.

If someone is willing to make me some custom textures I may be willing to do this.

You could also use toggling fog levels.

I’ll see if I can pull something off for this.

Rated rainbow for attempting something like this.

http://img10.imageshack.us/img10/4008/atmostsphere0001.jpg

Uh hows this lol (Made a little sample one)

Uses func_brushes with the sky_fake_white texture, and I’m using a custom skybox thats pitch black so I can have lighting on the level.