circle of latitude

A circle of latitude is a circle on the Earth's surface, of points with the same latitude, essentially the same distance from one of the poles (though given that the Earth is not quite spherical, a more precise definition is used which accommodates that fact). The five major circles of latitude are based on astronomy, particularly the relationship between the Earth and the Sun, and reflect the Earth's axial tilt. The major circles of latitude and their latitudes:

• Tropic of Cancer (≈23°26'11.8" N) - northern-most latitude over which the Sun ever reaches the zenith.
• Tropic of Capricorn (≈23°26'11.8" S) - southern-most latitude over which the Sun ever reaches the zenith.
• Arctic Circle (≈66°33'48.2" N) - latitude at which the Sun barely reaches the horizon (from below) on the December solstice.
• Antarctic Circle (≈66°33'48.2" S) - latitude at which the Sun barely reaches the horizon (from below) on the June solstice.
• Equator - (0°) - latitude equidistant from the poles.