orbit

Path of one body in space around another, such as the orbit of the Earth around the Sun or of the Moon around the Earth. Both bodies move around their common centre of mass. The movement of objects in orbit follows Kepler's laws, which apply to artificial satellites as well as to natural bodies.

As stated by the laws, the orbit of one body around another is an ellipse. The ellipse can be highly elongated, as are comet orbits around the Sun, or it may be almost circular, as are those of some planets. The closest point of a planet's orbit to the Sun is called perihelion; the most distant point is aphelion. (For a body orbiting the Earth, the closest and furthest points of the orbit are called perigee and apogee.)

orbit

In mammals, one of two bony cavities on either side of the nose in which the eyes are situated. They protect the eyes from injury because of the thickness of the bone at the front of the orbit.

The optic canal, which is the route between the optic nerve and the brain, opens into the rear of the orbits and nerves and blood vessels pass through the optical fissures. The eyes are held within the orbits by the extra-ocular muscles and the orbital septum.