| The plane of the Earth's orbit around the Sun. The ecliptic plane is used as the primary reference plane when describing the position of bodies in the solar system. Most objects in the solar system orbit in roughly this plane and in the same direction around the Sun as the Earth. There are exceptions such as many comets and a few minor planets which have high inclinations. Some comets even have retrograde orbits (e.g. Halley's comet) and orbit in the opposite direction to the planets. |