The force that causes Earth tides is primarily the gravitational force exerted by the Moon and, to a lesser extent, the Sun. The Moon's gravitational pull creates a tidal bulge on the side of the Earth facing the Moon and a corresponding bulge on the opposite side. These tidal bulges cause the oceans to rise and fall, resulting in high and low tides. Additionally, the Sun's gravitational force also contributes to the generation of tides, although its effect is about half as strong as the Moon's.
