Some objects have satellites coded in. For example, adding planets to the Sun will create the solar system. Adding moons to Jupiter will add the Galilean moons and then some. If pressing it has no effect, then it just means the satellites of that particular object is not coded into the game as of now, or it simply has no satellites.
Topic: What does the weird Add Planets to Star or Add Moons button do? (Read 3757 times)