Orbit of the Moon the Moon varies as it orbits Earth and hence is not always equal to the Moon's rotational velocity. When the Moon is at its perigee, its rotation is slower than its orbital motion, and this allows us to see up to eight degrees of longitude of its eastern (right) far side. Conversely, when the Moon reaches its apogee, its rotation is faster than its orbital motion and this reveals eight degrees of longitude of its western (left) far side. This is referred to as "longitudinal libration". Because the lunar orbit is also inclined to Earth's ecliptic plane by 5.1°, the
Earth, Moon, and Planets original research articles on formation of stars and planets, evolution of the Solar System including its origin, and the evolution of extra-solar systems including their origins. The focus also includes asteroids, comets, meteoroids, and near-Earth objects, Earth impact hazards, the Solar System-Earth relationship, and related topics. Research coverage encompasses physical and chemical properties of the above-mentioned celestial bodies, and their related chaotic behavior. This journal is abstracted and indexed in the following databases: Earth, Moon, and Planets Earth, Moon, and Planets is a peer-reviewed scientific journal, published approximately ten times per year by Springer Science+Business Media. It was established in