inclination

inclination in astronomy, the angle of intersection between two planes, one of which is an orbital plane. The inclination of the plane of the moon's orbit is 5°9′ with respect to the plane of the ecliptic (the plane of the earth's orbit around the sun). The inclination of the plane of the ecliptic relative to the plane of the earth's equator is 23°27′8.26′′; this angle is called the obliquity of the ecliptic.

inclination The angle between the horizontal and a magnetic vector. Conventionally, a vector with a magnetic north pole dipping below the horizontal is considered positive, and an upward vector is negative.

inclination (symbol i)
1. The angle between the orbital plane of a body and the reference plane centred on the object about which the body is revolving. For planets in the Solar System, the inclination of the orbit is usually given relative to the plane of the Earth's orbit, the ecliptic. For objects orbiting a planet, the inclination is usually given relative to the planet's equator. For double stars, the inclination is given relative to the plane of the sky. The inclination is one of the elements of an orbit.

2. The angle at which the rotation axis of a planet or satellite is tilted with respect to the perpendicular to some reference plane. The reference plane is usually the plane of the body's orbit.