Moon clouds. The illuminated area of the visible sphere (degree of illumination) is given by formula_3, where formula_4 is the elongation (i.e., the angle between Moon, the observer (on Earth) and the Sun). The gravitational attraction that masses have for one another decreases inversely with the square of the distance of those masses from each other. As a result, the slightly greater attraction that the Moon has for the side of Earth closest to the Moon, as compared to the part of the Earth opposite the Moon, results in tidal forces. Tidal forces affect both the Earth's crust and oceans. The
Sun and Moon (Middle-earth) for the Moon was the Silver Flower, and Gollum referred to it as the White Face. The Moon was more highly valued than the Sun by the Elves, both because it came from the Elder Tree, and because it rose first. In the universe of Middle-earth, the Moon was generally regarded as masculine, in recognition of Tilion. This gender corresponds with Máni, the personified moon in Norse mythology. In the early versions of "The Silmarillion" as described in "The Book of Lost Tales 1", a part of The History of Middle-earth series, the Sun was described in great detail as