Ok..... Suggestions!!
First things first... Get a better looking and higher resolution image to use as the earth surface. You could probably find one on Google... if Not i think i have an old one laying around on my hard drive i could post latter.
I think it's a nice night shot of the earth.... lots of pretty lights... :attn:
Next your going to need some stars in the background... this can be done with a simple image plane.
To get a better looking clouds you could do either of the following.... Create a new sphere around the first sphere, and map an Alpha image of some clouds. Add a slight Bump map, and this should look ok.
If you don't want to create multi spheres, you could overly the clouds with an alpha channel over the top of the earth texture using a Layered shader.... again apply a Bump map and see how it looks.
Now for some finishing touches... Create a sphere a tiny bit larger than the original, apply a Blinn shader, and in the Blinns attributes under special effects, turn on Glow effect, now check the hide source box (so that in the render you can't see the second sphere, you can only see a faint glow..... Now to make sure the glow looks right. Go to the Blinn shader with the Glow effect on, and change the color to a bluish with a haze orange (you can accomplish this with a ramp shader).
Well I'm going to end it here and see if this makes any sense to you.
If your having problems setting things up, just post back and i would be glad to go through it slowly.
Hope this helps.
www.stevenegan-cgi.com
"Your weapons are no match for ours! People of Mars, surrender!"
"Um, this isn't Mars. This is Earth."
"Earth? Earth-with-nuclear-weapons Earth?"
"Yes."
[long pause] "Friend!!"