[Space] How much does a Gas Giant heat it's moons?

[Captain Joy]

Originally Posted by Kraydak

2) Formation mechanism (direct gravitational collapse, like a star, or core-accretion building up a rocky core, like a planet). While more conceptually useful than definition (1), it doesn't make any observational predictions…

Direct gravitational collapse alone would result in an object with a solar nebula abundance. Core-accretion would result in an object with greater amounts of metals, rocky material, and possibly ices. It is possible that such a difference could be measurable or at least rule out certain formation models for certain objects.

To bring this back on topic: it seems based on everything I'm hearing that you can safely ignore the heat given off by a gas giant for it's moons, unless your system is still in the process of forming.