I took the source picture and extended the canvas on all sides.

I added a lighting effect (omni to give an even glow in all directions), and then invereted the image to make what was the light now the black.

This also inverted the base and objects inside the globe so with a layer mask I painted them back to their original colours.

I also filled in the bottom section (where the reflection will be) black, to just add some definition to that surface.

Next I used added the moon and stars (moon made by me) and used the spherise filter to make the stars in the middle seem bigger and the ones at the top and sides smaller).

Because of the small amount of light produced by the moon, I used the dodge/burn tools on the parts inside the globe to look like it was shining on them. I still wanted to keep this pretty dark so as not to lose the whole purpose of the night light.

At this point I put in some very feint highlights on the globe, and thats about it.

The final adjustments were to add the reflection and some feint shadows, and that's it.