World/Sky
These are options in "new" mission build (F3)

Alien Cloudy | Alien Foggy | Alien Night | Alien Starfield
Desert Day | Desert Sunset | Desert Starfield |
Ice Clear Day | Ice Clear Night | Ice StarField |
Lush Clear Day | Lush Lit Sky | Lush Night | Lush Starfield

World/Sky Cont.
These are options in "new" mission build (F3)

Mars Clear Day | Mars Cloudy Day | Mars Dusk | Mars Starfield
Mud Day | Mud Cloudy Night | Mud Dusk | Mud Starfield