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
Near-Earth object for spacecraft. , five near-Earth comets and three near-Earth asteroids have been visited by spacecraft, and probes are en route to two more NEAs. Plans to mine NEAs commercially have been drafted by private companies. The major technical astronomical definition for Near-Earth objects (NEOs) are small Solar System bodies with orbits around the Sun that by definition lie partly between 0.983 (perihelion) and 1.3 (aphelion) astronomical units (AU; Sun–Earth distance) away from the Sun. Thus, NEOs are not necessarily currently near the Earth, but they can potentially approach the Earth relatively closely. However, the term is also used more flexibly