The rules describe a terrestrial world as “one whose environmental conditions are broadly hospitable to human and other life”. At the same time, any satellite with a diameter of less than 6500 km has at best a “thin” atmosphere. It follows that a terrestrial world should have a size greater than 6500 km in order to support life. The chart below adjusts for this and can take the place of the World Diameter table in the rules in the case of terrestrial worlds.
It also allows for a greater variety of terrestrial worlds for characters to come from and visit.
Table 11-2a Terrestrial World Diameter (1d12)