The Tropic of Cancer, also referred to as the Northern Tropic, is the most northerly circle of latitude on the Earth at which the Sun may appear directly overhead at its culmination. This event occurs once per year, at the time of theNorthern solstice, when the Northern Hemisphere is tilted toward the Sun to its maximum extent. As of 16 April 2016, it lies at 23°26′13.8″ (or 23.43717°) north of the Equator.
Its Southern Hemisphere counterpart, marking the most southerly position at which the Sun may appear directly overhead, is the Tropic of Capricorn. These tropics are two of the five major degree measures or major circles of latitude that mark maps of the Earth, besides the Arctic and Antarctic Circles and the Equator. The positions of these circles of latitude (relative to the Equator) are dictated by the tilt of the Earth's axis of rotation relative to the plane of its orbit