Sky
 
Planet  (lighting from planet
not sun)
 
Sky   (with StarField) 
A bitmap can be added
 
 Deserttansky.ppl
Snow, Rain 

Do not show up in editor mode 
Changes the Properties of Snow, Rain 
 

 
LandScape
 
Alien
 
Desert
 
Ice
 
Mars
 
Mud
 
Lush