A couple of improvements.

Enabled AA, everything looks smoother.
Whenever you zoom, it zooms on the mouse.
When zoom is < 1, and the selected planet is in view, it locks it to the planet.
Period (or full stop key) will now centre the camera on the selected camera.
Fixed the title. :P
Added mouse position to debug menu.
Okay, I like the idea of zooming in on the mouse. But it does not work this way.
When you zoom in on the mouse, the position you point the mouse at in the world has to stay the same as before the zoom. I'll implement it that way.