Nice work i've seen...
Im no madhouse at pdn but, i tried out adding atmosphere to an earth made with shape3d.
Got bored, modified it, added to it and it built up to this.
Hm, use a flattened earth texture, some blurred layers, noise ect... mix it with this plugin(most important part)...
http://img85.imageshack.us/my.php?image ... mosvd9.png