The following keys are supported in addition to Control Screen keys.

The "G" button will only appear if your game supports the Give Planet functionality. It will have a yellow frame when you have given an order to give the planet away.

Reference

Keys:
F2 from almost everywhere
Related command:
UI.GotoScreen
Keymap:
PlanetScreen
Script context:
Planet()
This is a testing version.
It may be incomplete, and have more bugs (or features) than the public live version at planetscentral.com.