What concept did observing Jupiter holding four moons in orbit help observers grasp as a universal principle?

Answer

Gravity and orbital mechanics being universal principles

Seeing four distinct objects held in orbit by a distant primary body (Jupiter) showed that gravity and orbital mechanics were universal principles, not forces unique only to the Earth-Moon system.

What concept did observing Jupiter holding four moons in orbit help observers grasp as a universal principle?
Galileoastronomyobservationsheliocentric modelJupiter's moons