Quake3World

Hmm, I'd be going backwards with all of this, that is the feeling.

I don't know now. I can't see how I could create a small sphere in the radiant, I doubt there are any example files around.

You don't need any example files as it's pretty simple to do;

1) Draw a cube.
2) from "Curve" select "Cone".
3) press "V" and drag top-most point down ("Esc" or "V" to exit).
4) duplicate ("Space") and re-position.
5) texture (may need "Shift+S" to adjust alignment therein).

Is this sort of what you were getting at?

The other image was the first one, I had to scale it down, it looks odd. I took the object from a default map.

You said a "sphere" not a circle (flat plane). If you want the latter you literally just need to use a flat patch mesh or thin-ish brush volume (which needs nodraw on all other faces) and apply an alpha'd 'planet' image as the texture - it not really that much different from making and using a decal.

I was wondering why you were using a model. Like the other guys said, either a sphere made from patches, or a flat 2D textured surface with a shader seems like the best option.
If you want the image projected on to the skybox, maybe with some cool looking gas nebula clouds floating about, I think I would go the _skybox entity route. You can set up some neat backdrops to project on to the skybox that way, playing about with the alpha channel opacity to give an illusion of depth and distance to moving cloud layers.

Hang on posters,

I wanted a sphere with the Earth texture as a planet, I don't know how you'd create one, I thought the example with the cone was just to create an illusion of a planet that is round in GTK?

If you follow the instructions summary mentioned previously and ONLY pull the TOP vertex down you end up with a dome (half a sphere). Not entirely sure how you ended up with a flat pancake from that. And no it doesn't create the "illusion" of a planet, it creates a three-dimensional object you can then do stuff to/with (as donkey highlighted).

I'm finding it hard to imagine exactly what took place, I can't get my head around this set of instructions.

I realesed my map as a final, no response to it. I had left out the planet idea for the timebeing, I had also tried to get into contact with an actor from the tv series the map was based of, I don't know if the guy would want to record some samples for free, whether or not they would work in EF is another task.