A heliocentric orbit (also called circumsolar orbit) is an orbit around the Sun. All planets, comets, and asteroids in our Solar System are in such orbits, as are many artificial probes and pieces of debris. The moons of planets in the Solar System, by contrast, are not in heliocentric orbits as they orbit their respective planet.
While it is convenient to think of orbits around the Sun, bodies in the Solar System do not actually orbit the Sun. Instead, all bodies in the Solar System (including the Sun) actually orbit the barycenter of the Solar System. A similar phenomenon allows the detection of extrasolar planets by way of the radial velocity method.
The helio- prefix is derived from the ancient Greek word helios, meaning "sun", and also Helios, the personification of the Sun in Greek mythology.
Famous quotes containing the word orbit:
“The Fitchburg Railroad touches the pond about a hundred rods south of where I dwell. I usually go to the village along its causeway, and am, as it were, related to society by this link. The men on the freight trains, who go over the whole length of the road, bow to me as to an old acquaintance, they pass me so often, and apparently they take me for an employee; and so I am. I too would fain be a track-repairer somewhere in the orbit of the earth.”
—Henry David Thoreau (1817–1862)