Map of Earth
Longitude (λ)
Lines of longitude appear curved and vertical in this projection, but are actually halves of great circles.
Latitude (φ)
Lines of latitude appear straight and horizontal in this projection, but are actually circular with different radii. All locations with a given latitude are collectively referred to as a circle of latitude.
The equator divides the planet into a Northern Hemisphere and a Southern Hemisphere, and has a latitude of 0°.

On the Earth, a circle of latitude is an imaginary east-west circle that connects all locations with a given latitude. A location's position along a circle of latitude is given by its longitude. Based on a screenshot of a CIA World Factbook PDF. I cropped it, added text labels, and changed file format. ... For the acronyms, see MAP and MAPS. A map is a symbolized depiction of a space which highlights relations between components (objects, regions, themes) of that space. ... This article is about Earth as a planet. ... Longitude is the east-west geographic coordinate measurement most commonly utilized in cartography and global navigation. ... Latitude,usually denoted symbolically by the Greek letter phi, , gives the location of a place on Earth north or south of the equator. ... Horizontal plane is used in radio to plot a antennas relative field strength (which directly affects a stations coverage area) on a polar graph. ... World map showing the equator in red In tourist areas, the equator is often marked on the sides of roads The equator marked as it crosses Ilhéu das Rolas, in São Tomé and Príncipe. ... The Northern Hemisphere is the half of a planets surface (or celestial sphere) that is north of the equator (the word hemisphere literally means half ball). On the Earth, the Northern Hemisphere contains most of the land and about 90% of the human population. ... southern hemisphere highlighted in yellow (Antarctica not depicted). ... Image File history File links Download high-resolution version (3630x1870, 1364 KB) Summary The original is a GIMP native XCF format (16 MB) which contains the base map with lines contained on separate layers. ... This article is about Earth as a planet. ... The Experimental Advanced Superconducting Tokamak (EAST, internally called HT-7U) is a project being undertaken to construct an experimental superconducting tokamak magnetic fusion energy reactor in Hefei, the capital city of Anhui Province, in eastern China. ... A compass rose with west highlighted This article refers to the cardinal direction; for other uses see West (disambiguation). ... Latitude,usually denoted symbolically by the Greek letter phi, , gives the location of a place on Earth north or south of the equator. ... Longitude is the east-west geographic coordinate measurement most commonly utilized in cartography and global navigation. ...

Circles of latitude are often called parallels because they are a fixed distance apart, and on some map projections, including the Mercator projection, they are drawn parallel. They are also the intersections of the surface of the Earth with parallel planes. Circles of latitude near to the Poles are shorter than those near the Equator. Mercator world map Nova et Aucta Orbis Terrae Descriptio ad Usum Navigatium Emendate (1569) The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator, in 1569. ...

Arcs of circles of latitude are often used as boundaries between countries or regions that lack distinctive natural borders (e.g. in a desert).

Contrary to what might be assumed from their straight-line representation on some map projections, a circle of latitude is not, with the sole exception of the Equator, the shortest distance between two points lying on it. In other words, circles of latitude are not great circles, and are not really "lines" in the geometry of the sphere (see also great-circle distance). It is for this reason that an aeroplane travelling between a European and North American city on the same latitude will fly further north, over Greenland for example. For the Brisbane bus routes known collectively as the Great Circle Line (598 & 599), see the following list of Brisbane Transport routes A great circle on a sphere A great circle is a circle on the surface of a sphere that has the same diameter as the sphere, dividing the... Calabi-Yau manifold Geometry (Greek γεωμετρία; geo = earth, metria = measure) is a part of mathematics concerned with questions of size, shape, and relative position of figures and with properties of space. ... The great-circle distance is the shortest distance between any two points on the surface of a sphere measured along a path on the surface of the sphere (as opposed to going through the spheres interior). ...

A circle of latitude is perpendicular to all meridians at the intersection points, and is hence a special case of a loxodrome. On the earth, a meridian is a north-south line between the North Pole and the South Pole. ... Line crossing all meridians at the same angle. ...

Major circles of latitude

Diagram of major circles of latitude on the Earth.

The five major circles of latitude are, from north to south: Download high resolution version (1560x1024, 427 KB) Illumination of Earth by Sun on the day of winter solstice on northern hemisphere. ... Download high resolution version (1560x1024, 427 KB) Illumination of Earth by Sun on the day of winter solstice on northern hemisphere. ... This article is about Earth as a planet. ...

• The Arctic Circle (66° 33′ 38″ N)
• The Tropic of Cancer (23° 26′ 22″ N)
• The Equator (0° N)
• The Tropic of Capricorn (23° 26′ 22″ S)
• The Antarctic Circle (66° 33′ 38″ S)

These circles of latitude (excluding the equator) mark the divisions between the five main geographical zones. World map showing the Arctic Circle in red A sign along the Dalton Highway marking the location of the Arctic Circle The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. ... 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. ... World map showing the equator in red In tourist areas, the equator is often marked on the sides of roads The equator marked as it crosses Ilhéu das Rolas, in São Tomé and Príncipe. ... World map showing the Tropic of Capricorn For the novel by Henry Miller, see Tropic of Capricorn (novel). ... Zoomable PDF of the map this is based on The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. ... The torrid zone The temperate zones The frigid zones Each of the five main latitude regions of the earths surface is said to be a geographical zone, divided by the major circles of latitude. ...

Equator

The equator is the circle that is equidistant from both the North Pole and South Pole. It divides the Earth into the Northern Hemisphere and the Southern Hemisphere. For other uses, see North Pole (disambiguation). ... For other uses, see South Pole (disambiguation). ... The Northern Hemisphere is the half of a planets surface (or celestial sphere) that is north of the equator (the word hemisphere literally means half ball). On the Earth, the Northern Hemisphere contains most of the land and about 90% of the human population. ... southern hemisphere highlighted in yellow (Antarctica not depicted). ...

Equator

Image File history File links Download high-resolution version (3630x1870, 1364 KB) Summary The original is a GIMP native XCF format (16 MB) which contains the base map with lines contained on separate layers. ... World map showing the equator in red In tourist areas, the equator is often marked on the sides of roads The equator marked as it crosses Ilhéu das Rolas, in São Tomé and Príncipe. ...

Arctic and Antarctic Circles

The Arctic Circle marks the southernmost latitude (in the Northern Hemisphere) at which the sun can remain continuously above or below the horizon for 24 hours. Similarly, the Antarctic Circle marks the northernmost latitude (in the Southern Hemisphere) at which the sun can remain continuously above or below the horizon for 24 hours. The Northern Hemisphere is the half of a planets surface (or celestial sphere) that is north of the equator (the word hemisphere literally means half ball). On the Earth, the Northern Hemisphere contains most of the land and about 90% of the human population. ... southern hemisphere highlighted in yellow (Antarctica not depicted). ...

The latitude of these circles plus the Earth's axial tilt is equal to 90°. In astronomy, Axial tilt is the inclination angle of a planets rotational axis in relation to a perpendicular to its orbital plane. ...

Arctic Circle

Antarctic Circle

Image File history File links Download high-resolution version (3630x1870, 1365 KB) The original is a GIMP native XCF format (16 MB) which contains the base map with lines contained on separate layers. ... World map showing the Arctic Circle in red A sign along the Dalton Highway marking the location of the Arctic Circle The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. ... Image File history File links Download high-resolution version (3630x1870, 1371 KB) Summary The original is a GIMP native XCF format (16 MB) which contains the base map with lines contained on separate layers. ... Zoomable PDF of the map this is based on The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. ...

Tropics of Cancer and Capricorn

The Tropic of Cancer and Tropic of Capricorn respectively mark the northernmost and southernmost latitudes at which the sun may be seen directly overhead (at the June solstice and December solstice respectively). The June solstice occurs on June 21 or June 22 of most years, and is known by different names in different hemispheres of Earth: Summer solstice in the Northern Hemisphere; the longest day of the year. ... The December solstice occurs on December 21 or December 22 of most years, and is known by different names in different hemispheres of Earth: Winter solstice in the Northern Hemisphere; the shortest day of the year. ...

The latitude of the tropic circles is equal to the Earth's axial tilt. In astronomy, Axial tilt is the inclination angle of a planets rotational axis in relation to a perpendicular to its orbital plane. ...

Tropic of Cancer

Tropic of Capricorn

Image File history File links Download high-resolution version (3630x1870, 1356 KB) Summary The original is a GIMP native XCF format (16 MB) which contains the base map with lines contained on separate layers. ... 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. ... Image File history File links Download high-resolution version (3630x1870, 1364 KB) Summary The original is a GIMP native XCF format (16 MB) which contains the base map with lines contained on separate layers. ... World map showing the Tropic of Capricorn For the novel by Henry Miller, see Tropic of Capricorn (novel). ...

Movement of the Tropics and the Arctic and Antarctic circles

See also: Axial tilt.

By definition, the positions of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle all depend on the tilt of the Earth's axis relative to the plane of its orbit around the sun, known technically as the "obliquity of the ecliptic". As of 2000, the mean value of the tilt was about 23°26′21″. However, this angle is not constant, but has a complex motion determined by the superimposition of many different cycles with short to very long periods. As the axial tilt varies, so do the positions of the Tropics and the Arctic and Antarctic circles. In astronomy, Axial tilt is the inclination angle of a planets rotational axis in relation to a perpendicular to its orbital plane. ... In astronomy, Axial tilt is the inclination angle of a planets rotational axis in relation to a perpendicular to its orbital plane. ...

The main long-term cycle causes the axial tilt to fluctuate between about 22.5° and 24.5° with a 41,000 year periodicity. As a consequence of this cycle the average value of the tilt is currently decreasing by about 0.47″ per year. This causes the Tropics of Cancer and Capricorn to drift towards the equator by about 15 metres per year, and the Arctic and Antarctic Circles to drift towards the Poles by the same amount. As a result of the movement of the Tropics of Cancer and Capricorn, the area of the Tropics decreases worldwide by about 1100 square kilometres per year on average. A noontime scene from the Philippines on a day when the sun is almost directly overhead. ...

The Earth's axial tilt is subject to additional shorter-term variations due to nutation, of which the main term, with a period of 18.7 years, has an amplitude of 9"21 (corresponding to almost 300 metres north and south). There are then still many smaller terms, resulting in varying daily shifts of some metres in any direction. Rotation (green), Precession (blue) and Nutation (red) of the Earth Nutation is a slight irregular motion (etymologically a nodding) in the axis of rotation of a largely axially symmetric object, such as a gyroscope or a planet. ...

Finally, the Earth's rotational axis is not exactly fixed with respect to the Earth, but undergoes very small fluctuations, called polar motion, which have a small theoretical effect on the positions of the abovementioned parallels. This article needs to be wikified. ...

Short-term fluctuations over a matter of days do not directly affect the location of the extreme latitudes at which the sun may appear directly overhead, or at which 24-hour day or night is possible, except when they actually occur at the time of the solstices. Rather, they cause a theoretical shifting of the parallels, that would occur if the given axis tilt were maintained throughout the year.

Other notable parallels