Which celestial body influence earth tides?
Actually – while the moon is the major influence, the sun also plays a role. Hence Spring and Neap tides. When the moon and sun line up (New Moon or Full Moon) we have spring tides with a larger difference between low and high tide. This is because the direction of gravitational action is the same and so they act together. When the moon is at right angles to the direction to the sun (quarter moon phases) we get Neap tides with smaller difference between high and low tide. This is because the action of the sun is perpendicular to that of the moon. So I would argue you need 2 celestial bodies. If you have to pick just one – then the moon is more important.
