Tropic of Cancer Markers

The Tropic of Cancer, also known as the Northern Tropic, is the Earth's northernmost circle of latitude where the Sun can be seen directly overhead. This occurs on the June solstice, when the Northern Hemisphere is tilted toward the Sun to its maximum extent. It also reaches 90 degrees below the horizon at solar midnight on the December solstice. Using a continuously updated formula, the circle is currently 23°26′09.4″ (or 23.43594°) north of the Equator. In geopolitics, it is known for being the southern limitation on the mutual defense obligation of NATO, as member states of NATO are not obligated to come to the defense of territory south of the Tropic of Cancer.