Topic summary
Tropic
Extracted from the Wikipedia article Tropics.
The Earth's axial tilt is currently around 23.4°, and therefore so are the latitudes of the tropical circles, marking the boundary of the tropics: specifically, ±23°26′09.0″ (or 23.43582°). The northern one is called the Tropic of Cancer, and the southern is the Tropic of Capricorn. As the Earth's axial tilt changes, so too do the tropical and polar circles.