An equator is the intersection of a sphere A sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point. This distance r is known as the radius of the sphere. The's surface with the plane In mathematics, a plane is any flat, two-dimensional surface. A plane is the two dimensional analogue of a point , a line (one-dimension) and a space (three-dimensions). Planes can arise as subspaces of some higher dimensional space, as with the walls of a room, or they may enjoy an independent existence in their own right, as in the setting of perpendicular to the sphere's axis of rotation A rotation is a movement of an object in a circular motion. An object rotates around a center of rotation. A three-dimensional object rotates always around an imaginary line called an axis as the Euler's rotation theorem shows. If the axis of rotation is within the body, the body is said to rotate upon itself, or spin—which implies relative and containing the sphere's center of mass The center of mass of a system of particles is the point at which the system's whole mass can be considered to be concentrated for the purpose of calculations. The center of mass is a function only of the positions and masses of the particles that compose the system. In the case of a rigid body, the position of its center of mass is fixed in. The capitalized term Equator refers to the Earth Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the World, the Blue Planet,[note 6] or by its Latin name, Terra.[note 7]'s equator.
In simpler language, the Equator is an imaginary line on the Earth's surface equidistant from the North Pole The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets the Earth's surface. It should not be confused with the North Magnetic Pole and South Pole The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's axis of rotation intersects its surface. It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole. Situated on the continent of Antarctica, it is the site of that divides the Earth into a Northern Hemisphere The Northern Hemisphere is the half of a planet that is north of equator—the word hemisphere literally means 'half sphere'. It is also that half of the celestial sphere north of the celestial equator. Earth's northern hemisphere contains most of its land area and most of its human population and a Southern Hemisphere The Southern Hemisphere is the half of a planet that is south of the equator—the word hemisphere (from the Greek word σφαιρα +ημι(half)) literally means 'half ball'. It is also that half of the celestial sphere south of the celestial equator. The equators of other planets A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.[a] and astronomical bodies are defined analogously.
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Geodesy of the Equator
Road sign marking the Equator near Nanyuki Nanyuki is a market town in central Kenya, lying northwest of Mount Kenya along the A2 road and at the terminus of the branch railway from Nairobi. It is situated just north of the Equator . It was founded in 1907 by British settlers, some of whose descendants still live in and around the town. Nanyuki is now the main airbase of the Kenya Air, KenyaThe latitude Latitude, usually denoted by the Greek letter phi gives the location of a place on Earth (or other planetary body) north or south of the equator. Lines of Latitude are the imaginary horizontal lines shown running east-to-west (or west to east) on maps (particularly so in the Mercator projection) that run either north or south of the equator of the Equator is 0°. The length of Earth Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the World, the Blue Planet,[note 6] or by its Latin name, Terra.[note 7]'s equator is 40,008.629 kilometres (24,860.2 mi). The Equator is one of the five main circles of latitude A circle of latitude, on the Earth, is an imaginary east-west circle connecting all locations that share a given latitude. A location's position along a circle of latitude is given by its longitude on Earth (the others being the Polar Circles A polar circle is either the Arctic Circle or the Antarctic Circle. On Earth, the Arctic Circle is located at a latitude of 66˚ 34', and the Antarctic Circle is located at a latitude of 66˚ 34' S and the Tropical Circles). It is the only line of latitude which is also a great circle A great circle of a sphere is a circle that runs along the surface of that sphere so as to cut it into two equal halves . That is, it is the intersection of a sphere and a plane which passes through the center point of that sphere. All great circles of a given sphere have both the same circumference and the same center as the sphere. A great. The imaginary circle obtained when the Earth's equator is projected onto the sky is called the celestial equator The celestial equator is a great circle on the imaginary celestial sphere, in the same plane as the Earth's equator. In other words, it is a projection of the terrestrial equator out into space. As result of the Earth's axial tilt, the celestial equator is inclined by ~23.5° with respect to the ecliptic plane.
The Sun The Sun is the star at the center of the Solar System. It has a diameter of about 1,392,000 kilometers , about 109 times that of Earth, and its mass (about 2 × 1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. About three quarters of the Sun's mass consists of hydrogen, while the rest is in its seasonal A season is a division of the year, marked by changes in weather, ecology, and hours of daylight movement through the sky, passes directly over the Equator twice each year A year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic, on the March and September equinoxes An equinox occurs twice a year, when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the centre of the Sun being in the same plane as the Earth's equator. The term equinox can also be used in a broader sense, meaning the date when such a passage happens. The name "equinox" is derived from the Latin aequus. At the Equator, the rays of the sun are perpendicular In geometry, two lines or planes , are considered perpendicular (or orthogonal) to each other if they form congruent adjacent angles (a T-shape). The term may be used as a noun or adjective. Thus, referring to Figure 1, the line AB is the perpendicular to CD through the point B. Note that by definition, a line is infinitely long, and strictly to the surface of the earth on these dates.
The Equator marked as it crosses Ilhéu das Rolas Ilhéu das Rolas is a small island in São Tomé and Príncipe, in Africa. The island lies on the equator, off the southern tip of São Tomé Island. It is in the Caué District of São Tomé Province. The island is home to a small resort, in São Tomé and PríncipePlaces on the Equator experience the quickest rates of sunrise Sunrise is the instant at which the upper edge of the Sun appears above the horizon in the east. Sunrise should not be confused with dawn, which is the point at which the sky begins to lighten, some time before the sun itself appears, ending twilight. Because atmospheric refraction causes the sun to be seen while it is still below the horizon, and sunset Sunset or sundown is the daily disappearance of the sun below the horizon as a result of the Earth's rotation. The atmospheric conditions created by the setting of the sun, occurring before and after it disappears below the horizon, are also commonly referred to as "sunset" in the world. They are also the only places in the world where the sun can go directly from the zenith In general terms, the zenith is the direction pointing directly "above" a particular location; that is, it is one of two vertical directions at the location, orthogonal to a horizontal flat surface there. The concept of "above" is more specifically defined in astronomy, geophysics and related sciences as the vertical direction to the nadir The nadir is the direction pointing directly below a particular location; that is, it is one of two vertical directions at the location, orthogonal to a horizontal flat surface there. Since the concept of being below is itself somewhat vague, scientists define the nadir in more rigorous terms. Specifically, in astronomy, geophysics and related and from the nadir The nadir is the direction pointing directly below a particular location; that is, it is one of two vertical directions at the location, orthogonal to a horizontal flat surface there. Since the concept of being below is itself somewhat vague, scientists define the nadir in more rigorous terms. Specifically, in astronomy, geophysics and related to the zenith In general terms, the zenith is the direction pointing directly "above" a particular location; that is, it is one of two vertical directions at the location, orthogonal to a horizontal flat surface there. The concept of "above" is more specifically defined in astronomy, geophysics and related sciences as the vertical direction. Such places also have a theoretical constant 12 hours of day and night throughout the year, though in practice there are variations of a few minutes due to the effects of atmospheric refraction and because sunrise and sunset are measured from the time the edge of the Sun's disc is on the horizon The horizon is the apparent line that separates earth from sky, the line that divides all visible directions into two categories: those that intersect the Earth's surface, and those that do not. At many locations, the true horizon is obscured by trees, buildings, mountains, etc., and the resulting intersection of earth and sky is called the, rather than its centre.
The Earth bulges slightly at the Equator An equatorial bulge is a bulge which a planet may have around its equator, distorting it into an oblate spheroid. The Earth has an equatorial bulge of 42.72 km due to its rotation: its diameter measured across the equatorial plane (12756.28 km, 7,927 miles) is 42.72 km more than that measured between the poles (12713.56 km, 7,900 miles). It has an average diameter of 12,750 kilometres (7,922 mi), but at the Equator the diameter is approximately 43 kilometres (27 mi) greater than the polar diameter.
A monument marking the Equator at the city of Pontianak, Indonesia Pontianak is the capital of the Indonesia province of West Kalimantan. It is a medium-size industrial city on the island of Borneo. It occupies an area of 107.82 km² in the delta of the Kapuas River, at approximately 1143 km, the longest river in Indonesia and the 133rd-longest river in the World by length. It is located precisely on the equatorLocations near the Equator are good sites for spaceports A spaceport, astrodrome or cosmodrome is a site for launching (or receiving) spacecraft, by analogy with seaport for ships or airport for aircraft. The word spaceport, and even more so cosmodrome, has traditionally been used for sites capable of launching spacecraft into orbit around Earth or on interplanetary trajectories. However, rocket launch, such as the Guiana Space Centre The Guiana Space Centre or, more commonly, Centre Spatial Guyanais is a French spaceport near Kourou in French Guiana. Operational since 1968, it is particularly suitable as a location for a spaceport due to its proximity to the equator, and that launches are in a favourable direction over water. The European Space Agency, the French space agency in Kourou Kourou is a commune in French Guiana, an overseas region and department of France located in South America, French Guiana French Guiana is an overseas region of France, consisting of a single overseas department (French: département d'outre-mer, or DOM) located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west. Its 83,534 km² have a very low population density of less than three, as they are already moving faster than any other point on the Earth due to the Earth's rotation, and the added velocity reduces the amount of fuel needed to launch spacecraft. Spacecraft launched in this manner must launch to the east to use this effect.
For high precision work, the Equator is not quite as fixed as the above discussion implies. The true equatorial plane must always be perpendicular to the Earth's spin axis. Although this axis is relatively stable, its position wanders Polar motion of the earth is the movement of Earth's rotation axis across its surface. This is measured with respect to a reference frame in which the solid Earth is fixed . This variation is only a few meters in an approximately 9 metres (30 ft) radius circular motion each year. Thus, the true equator moves slightly, but this effect is only relevant to detailed scientific studies.
Equatorial seasons and climate
The "Marco Zero" in Macapá Macapá is the capital of the state of Amapá in Brazil, on the Amazon River. With a population of 366,484 people in 2009, mining is central to its economy. It exports tin iron, gold, and manganese, as well as lumber, oil, animal pelts, and fish. Manufactures include rubber products and food. Founded in 1688 by military men in the vicinity of a, Brasil Brazil (pronounced /brəˈzɪl/ ; Portuguese: Brasil, IPA: [bɾaˈziw]), officially the Federative Republic of Brazil (Portuguese: República Federativa do Brasil, listen (help·info)), is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population. It is the only Portuguese-speaking.Near the Equator there is little distinction between summer, winter, autumn or spring. Temperatures are high year round (permanent "summer"), with the exception of periods during the wet season and at higher altitudes. In many tropical regions people identify two seasons: wet and dry. However, most places close to the Equator are wet throughout the year, and seasons can vary depending on a variety of factors including elevation and proximity to an ocean. The rainy and humid conditions mean that the equatorial climate is not the hottest in the world.
The surface of the Earth at the Equator is mostly ocean. The highest point on the Equator is 4,690 metres (15,387 ft), at 0°0′0″N 77°59′31″W / 0°N 77.99194°W), on the south slopes of Volcán Cayambe Cayambe is the name of a volcano located in the Cordillera Oriental, a branch of the Ecuadorian Andes. It is located in Pichincha province some 70 km (43 mi) northeast of Quito. It is the third highest mountain in Ecuador (summit 5,790 metres (18,996 ft)) in Ecuador. This is a short distance above the snow line, and this point and its immediate vicinity form the only section of the Equator where snow lies on the ground.
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Thu, 15 Jul 2010 20:39:13 GMT+00:00
Politically Illustrated (blog) It will empower activists, media and good-governance watchdogs, both south of the equator and north, to ensure the continent's vast riches end up in ...
