Which is most responsible for the ocean tides?
The Moon has a much, much greater affect on the tides. The difference in gravitational pull between the point on the Earth closest to, and the point on the Earth farthest away from the object observing the gravitational pull is what determines how large the tide is. The percentage difference in the distance between the point on the Earth closest to the Moon and the point on the Earth farthest away from the Moon is much, much larger than the percentage difference in the distance between the point on the Earth closest to the Sun and the point on the Earth farthest away from the Sun. So, even though the Sun is much larger than the Moon, the very large distance the Sun is from the Earth as compared to the Moon more than makes up for the large difference in mass. .
