More planet sizes

[Suicide Junkie]

No, a typical null planet will appear in a star system, invisible to the eye, but selectable if you click the right sector.

IIRC,
Where a normal planet has:
Ice - Hydrogen
Size - Medium
Conditions - Mild
Value 25%/70%/1%

The null planet has:
-
Size -
Conditions -
Value 25%/70%/1%

They are usually quite rare, hence the need for the ancient race trait.