Tidal forces ความหมาย คือ the gravitational pull on planetary objects from nearby planets and moons. When the tidal forces of a planet and several moons are focused on certain moons, particularly if the orbits of the various objects bring them into alignment on a repeated basis, the tidal forces can generate a tremendous amount of energy within the moon. The intense volcanic acivity of Io is the result of the interaction of such tidal forces.