:''For the novel by
Henry Miller, see
Tropic of Cancer (novel).''

World map showing the Tropic of Cancer
The 'Tropic of Cancer', or 'Northern tropic', is one of the five major
circles of latitude that mark maps of the Earth. It is the most northerly latitude at which the sun can appear directly overhead at noon. This event occurs at the
June solstice, when the northern hemisphere is tilted towards the sun to its maximum extent.
The Tropic of Cancer currently lies 23
° 26′ 22″ north of the
Equator. North of this latitude are the
subtropics and
Northern Temperate Zone. The equivalent line of latitude south of the equator is called the
Tropic of Capricorn, and the region between the two, centered on the Equator, is known as the
Tropics.
The line is called Tropic of Cancer because when it was named the sun was in the location of the
constellation of
Cancer (
Latin for ''
crab'') in the sky at the June solstice. However, due to the
precession of the equinoxes, the sun is now in the location of the constellation of
Taurus at the June solstice. The word "tropic" itself comes from the Greek ''tropos'', meaning ''turn'', referring to the fact that the sun appears to "turn back" at the solstices.
The position of the Tropic of Cancer is not fixed, but varies in a complex manner over time; see under
circles of latitude for information.
Geography
The Tropic of Cancer passes through the following countries (going east):
★
United States of America (
Hawaii) - sea area only, misses every island, passing between
Nihoa and
Necker Island
★
Mexico just north of
Mazatlan on the
Pacific
★
Bahamas -
Exuma Islands and
Long Island
★
Western Sahara (claimed by
Morocco)
★
Mauritania
★
Mali
★
Algeria
★
Niger
★
Libya
★
Chad – Its northernmost point is defined by the Tropic of Cancer.
★
Egypt
★
Saudi Arabia
★
United Arab Emirates (
Abu Dhabi emirate only)
★
Oman
★
India
★
Bangladesh
★
Myanmar
★
People's Republic of China just north of
Guangzhou, also known as Canton
★
Republic of China (
Taiwan)
Circumnavigation
According to the
Fédération Aéronautique Internationale's rules, for a flight to compete for a round-the-world speed record, it must cover a distance no less than the length of the Tropic of Cancer as well as cross all
meridians and end on the same airfield where it started. This length is set to be 36787.559 kilometres - a number implying a precision which does not exist, considering the variations of the tropic described above.
For an ordinary
circumnavigation the rules are somewhat relaxed and the distance is set to a rounded value of 37000 kilometres.
See also
★
Tropic of Capricorn
★
Arctic Circle
★
Antarctic Circle
★
Equator