Moons need to be more diverse in both coloring and military/economic value.
as it stands they are just another asteroid by your HW.
Moons are incredibly diverse (just look at our solar system).
A few ideas to spice moons up:
Mini volcano moons for higher tactical slots (maybe 4 more starting) ~ similar to Io
Special ability: 4 more tactical slots
Moons with atmospheres that can support life (higher population for taxes) ~ Still looking for these out there in space
Special ability: 20 higher population
Moons with abundant natural resources that would greatly aid in production (all metal resource asteroids)~ titan, ganymede
Special ability: 15% faster ship production at this moon
Ice moons that would be good for getting early crystal production (all crystal asteroids) ~ similar to europa
Special ability: 4 more logistics slots
Asteroid Belt 5 population max, 4-5 low yield resource nodes
Special ability: 10% more damage for all friendly ships in the gravity well using superior knowledge of the belt
Special ability: 1 more Hitpoint upgrade level bringing them to 4000 max HP