Oberon (moon) numbering (where Titania and Oberon are II and IV). In 1851 Lassell eventually numbered all four known satellites in order of their distance from the planet by Roman numerals, and since then Oberon has been designated '. Oberon orbits Uranus at a distance of about 584,000 km, being the farthest from the planet among its five major moons. Oberon's orbit has a small orbital eccentricity and inclination relative to the equator of Uranus. Its orbital period is around 13.5 days, coincident with its rotational period. In other words, Oberon is a synchronous satellite, tidally locked, with one face always pointing
Orbit of the Moon rearward loops in the Moon's solar orbit. Considering the Earth–Moon system as a binary planet, its centre of gravity is within Earth, about or 72.6% of the Earth's radius from the centre of the Earth. This centre of gravity remains on the line between the centres of the Earth and Moon as the Earth completes its diurnal rotation. The path of the Earth–Moon system in its solar orbit is defined as the movement of this mutual centre of gravity around the sun. Consequently, Earth's centre veers inside and outside the solar orbital path during each synodic month as the Moon