2. The curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.
3. The path of a body in a field of force surrounding another body; for example, the movement of an atomic electron in relation to a nucleus.
4. A range of activity, experience, or knowledge; a range of control or influence.
5. The usual course of one's life or range of one's activities.
6. The sphere of power or influence, as of a nation or person: a small nation in the Russian orbit.
7. In physics, the path traced by an electron revolving around the nucleus of an atom.
8. An orb or sphere.
9. In zoology, the part surrounding the eye of a bird or insect.
10. Either of two bony cavities in the skull containing an eye and its external structures; an eye socket.
When the two bodies are similar in mass, as in a binary star, both bodies move around their common center of mass.
The movement of objects in orbit follow Johann Kepler's laws, which apply to artificial satellites as well as to natural bodies.2. The path followed by one object around another as a result of their mutual gravitational interaction.
As a result of the inverse square law of gravitation, planetary orbits are approximately conic sections.