The precise location of the equator is not truly fixed; the true equatorial plane is perpendicular to the Earth's rotation axis, which drifts about during a year. This effect must be accounted for in detailed geophysical measurements. Geological samples show the equator significantly changed positions between 12 and 48 million years ago, as sediment deposited by ocean thermal currents at the equator have shifted. The deposits by thermal currents are determined by the axis of the earth, which determines solar coverage of the Earth's surface. Changes in Earth axis can also be observed in the geographic layout of volcanic island chains, which are created by shifting hot spots under the Earth's crust as the axis and crust move.
Precise location
Equator
Equator | Precise location
The precise location of the equator is not truly fixed; the true equatorial plane is perpendicular to the Earth's rotation axis, which drifts about during a year. vIt is the imaginary line on the spheroid, equidistant from its poles, dividing it into northern and southern hemispheres. The precise location of the equator is not truly fixed; the true equatorial plane is perpendicular to the Earth's rotation axis, which drifts about during a year. The precise location of the equator is not truly fixed; the true equatorial plane is perpendicular to the Earth's rotation axis, which drifts about during a year. This effect must be accounted for in detailed geophysical measurements
what are the major global wind systems on earth
user
polar easterlies, westerlies to name a few.
assistant
what is the first one about?
user
are the dry, cold prevailing winds that blow from the high-pressure areas towards the low-pressure areas.
assistant
how does it effect the precipitation?
user
Orographic precipitation occurs on the windward side of mountains and is caused by the rising air motion of a large-scale flow of moist air across the mountain ridge, resulting in adiabatic cooling and condensation.
assistant
are there any trade that depend on this?
user
Yes, The trade winds.
assistant
what does it mean?
user
They are the prevailing pattern of easterly surface winds found in the tropics near the Earth's equator.
assistant
what is the length of the last thing mentioned?
user
The equator is 0.16% longer than a meridian.
assistant
where is it located?
user
The precise location of the equator is not truly fixed; the true equatorial plane is perpendicular to the Earth's rotation axis, which drifts about during a year. This effect must be accounted for in detailed geophysical measurements. Geological samples show the equator significantly changed positions between 12 and 48 million years ago, as sediment deposited by ocean thermal currents at the equator have shifted. The deposits by thermal currents are determined by the axis of the earth, which determines solar coverage of the Earth's surface. Changes in Earth axis can also be observed in the geographic layout of volcanic island chains, which are created by shifting hot spots under the Earth's crust as the axis and crust move.
Equator | Precise location
Its location is in "Jalan Khatulistiwa," literally translated into "Equator Road", North Pontianak, about 3 kilometres from the city centre of Pontianak. The equator monument is not on the equator any more. Land masses are affected by plate tectonics, and Earth's equator itself moves due to the precession of the equinoxes and nutation. The equator has moved slightly southwards and there is another line outside the monument, that shows the recorded position in 2005. The position of the equator in 2010 is even further south and now is in a river, as a GPS device can confirm.
The Equator monument | Location
This correlates with Indian plate crashing into Asia and Himalayan uplift.
Equator | Precise location
A value in decimal degrees to 5 decimal places is precise to 1.1132 m at the equator. Elevation also introduces a small error: at 6,378 m elevation, the radius and surface distance is increased by 0.001 or 0.1%. Because the earth is not flat, the precision of the longitude part of the coordinates increases the further from the equator you get. The precision of the latitude part does not increase so much, more strictly however, a meridian arc length per 1 second depends on the latitude at the point in question. The discrepancy of 1 second meridian arc length between equator and pole is about 0.3 metres because the earth is an oblate spheroid.
Decimal degrees | Precision
For both GRS 80 and WGS 84, this results in a length for the equator of . The geographical mile is defined as one arc-minute of the equator, so it has different values depending on which radius is assumed. For example, by WSG-84, the distance is , while by IAU-2000, it is . This is a difference of less than over the total distance (approximately ). The earth is commonly modeled as a sphere flattened 0.336% along its axis. This makes the equator 0.16% longer than a meridian (a great circle passing through the two poles). The IUGG standard meridian is, to the nearest millimetre, , one arc-minute of which is , explaining the SI standardization of the nautical mile as , more than less than the geographical mile.
Equator | Exact length
You also notice just how far north the United States, Europe, and Asia are. Standing at the equator, you really have to strain your neck to see them.
Mapparium | View from within
It is located at . latitude and longitude. It is located at Google Maps
Malayinkeezhu | Geography
The radius of the semi-major axis of the Earth at the equator is 6,378,137.0 m resulting in a circumference of 40,075,016.7 m. The equator is divided into 360 degrees of longitude, so each degree at the equator represents 111,319.5 m or approximately 111.32 km. As one moves away from the equator towards a pole, however, one degree of longitude is multiplied by the cosine of the latitude, decreasing the distance, approaching zero at the pole. The number of decimal places required for a particular precision at the equator is: A value in decimal degrees to a precision of 4 decimal places is precise to 11.132 m at the equator.
Decimal degrees | Precision
The Equator monument is located on the equator in Pontianak, Indonesia. It marks the division between the northern and southern hemispheres.
The Equator monument | Introduction
This position is in Coma Berenices, near the bright star Arcturus; likewise, the south galactic pole lies in the constellation Sculptor. The "zero of longitude" of galactic coordinates was also defined in 1959 to be at position angle 123° from the north celestial pole. Thus the zero longitude point on the galactic equator was at , (B1950) or , (J2000), and its J2000 position angle is 122.932°. The galactic center is located at position angle 31.72° (B1950) or 31.40° (J2000) east of north.
Galactic plane | Introduction
Earth's Equator, spelled with capital E, is a specific case of a planetary equator. It is about long, of which 78.8% lies across water and 21.3% over land. In spatial (3D) geometry, as applied in astronomy, the equator of a rotating spheroid (such as a planet) is the parallel (circle of latitude) at which latitude is defined to be 0°. It is the imaginary line on the spheroid, equidistant from its poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane perpendicular to its axis of rotation and midway between its geographical poles.
Equator | Introduction
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and midway between the poles. On Earth, "the Equator", at 0° latitude, divides the Northern and Southern Hemispheres. Equator may also refer to:
Equator (disambiguation) | Introduction
A location's north–south position along a meridian is given by its latitude, which is approximately the angle between the local vertical and the equatorial plane.
Longitude | Introduction
In Meridian arc and standard texts it is shown that the distance along a meridian from latitude to the equator is given by ( in radians) where is the meridional radius of curvature. The distance from the equator to the pole is
Latitude | Length of a degree of latitude
Now find the point N on the equator which is such that the number of equatorial degrees in ON is numerically equal to the latitude difference (45° for AM on the unequal scale). Draw the perpendicular through N and let it meet OQ at D. Find the point E such that OE=OD, here approximately 54°. This is a measure of the rhumb line distance between the points on the sphere corresponding to A and B on the spherical Earth. Since each degree on the equator corresponds to 60 nautical miles the sailing distance is 3,240 nautical miles for this example.
Mercator 1569 world map | Distances and the Organum Directorium
To a person on Earth, the Sun appears to travel above the equator (or along the celestial equator) at these times. Light rays from the Sun's center are perpendicular to Earth's surface at the point of solar noon on the equator. Locations on the equator experience the shortest sunrises and sunsets because the Sun's daily path is nearly perpendicular to the horizon for most of the year. The length of daylight (sunrise to sunset) is almost constant throughout the year; it is about 14 minutes longer than nighttime due to atmospheric refraction and the fact that sunrise begins (or sunset ends) as the upper limb, not the center, of the Sun's disk contacts the horizon.
Equator | Overview
The equator is the circle that is equidistant from the North Pole and South Pole. It divides the Earth into the Northern Hemisphere and the Southern Hemisphere. Of the parallels or circles of latitude, it is the longest, and the only 'great circle' (a circle on the surface of the Earth, centered on Earth's center). All the other parallels are smaller and centered only on Earth's axis.
Circle of latitude | Equator
Following is a list of circles of latitude on Earth.
List of circles of latitude | Introduction
In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −24.54° and −40.42°.
Antlia | Characteristics
The central square of Quito is located about south of the equator; the city itself extends to within about of zero latitude. A monument and museum marking the general location of the equator is known locally as "la mitad del mundo" (the middle of the world), to avoid confusion, as the word "" is Spanish for equator.
Quito | Introduction
To avoid negative numbers in the input data, the system specifies that latitude is measured from the South Pole to the North Pole, and longitude measured eastward from the antimeridian of Greenwich, giving the Prime Meridian a false easting of 180° and the equator a false northing of 90°.
Maidenhead Locator System | Description of the system
The position of the current geodetic prime meridian is not identified at all by any kind of sign or marking (as the older astronomic position was) in Greenwich, but can be located using a GPS receiver.
Meridian (geography) | Geographic
Therefore, the meridian distance from the equator to latitude is The distance formula is simpler when written in terms of the parametric latitude, where and . The distance from the equator to the pole, the quarter meridian, is
Meridian arc | Calculation
Roughly, the latitude of a place on Earth is its angular distance north or south of the equator. Latitude is usually expressed in degrees (marked with °) ranging from 0° at the Equator to 90° at the North and South poles. The latitude of the North Pole is 90° N, and the latitude of the South Pole is 90° S. Mariners calculated latitude in the Northern Hemisphere by sighting the North Star Polaris with a sextant and using sight reduction tables to correct for height of eye and atmospheric refraction. The height of Polaris in degrees above the horizon is the latitude of the observer, within a degree or so.
Navigation | Latitude
At the Equator, the daytime period always lasts about 12 hours, regardless of season. As viewed from the Equator, the Sun always rises and sets vertically, following an apparent path nearly perpendicular to the horizon. Due to the axial tilt of Earth, Sun always lies within 23.44° north or south of the celestial equator, so the subsolar point always lies within the tropics. From the March equinox to the September equinox, the Sun rises within 23.44° north of due east, and sets within 23.44° north of due west. From the September equinox to the March equinox, the Sun rises within 23.44° south of due east and sets within 23.44° south of due west.
Daytime | At the Equator
The celestial equator currently passes through these constellations:
Celestial equator | Introduction
Calling the ruler distances of the end points on the map meridian as measured from the equator "y" and "y", the true distance between these points on the sphere is given by using any one of the inverse Mercator formulæ: where "R" may be calculated from the width "W" of the map by "R" = . For example, on a map with "R" = 1 the values of "y" = 0, 1, 2, 3 correspond to latitudes of "φ" = 0°, 50°, 75°, 84° and therefore the successive intervals of 1 cm on the map correspond to latitude intervals on the globe of 50°, 25°, 9° and distances of 5,560 km, 2,780 km, and 1,000 km on the Earth.
Mercator projection | On a meridian
This contrasts with the small (1%) increase in the length of a degree of latitude (north-south distance), equator to pole. The table shows both for the WGS84 ellipsoid with = and = . Note that the distance between two points 1 degree apart on the same circle of latitude, measured along that circle of latitude, is slightly more than the shortest (geodesic) distance between those points (unless on the equator, where these are equal); the difference is less than .
Longitude | Length of a degree of longitude
Despite its name, no part of the country's territory lies on the equator—it is in the northern hemisphere, except for the insular Annobón Province, which is about south of the equator.
Equatorial Guinea | Geography
The 45×90 points are the four points on Earth which are halfway between the geographical poles, the equator, the Prime Meridian, and the 180th meridian.
45×90 points | Introduction
Similarly, latitude is the number of degrees north or south of the Equator. Because latitude and longitude are expressed "relative" to these lines, a position expressed in latitude and longitude is also a relative location.
Location | Absolute location
In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −67.48° and −83.12°.
Apus | Characteristics
The latitude of the Earth's equator is, by definition, 0° (zero degrees) of arc. The equator is one of the five notable circles of latitude on Earth; the other four are both polar circles (the Arctic Circle and the Antarctic Circle) and both tropical circles (the Tropic of Cancer and the Tropic of Capricorn). The equator is the only line of latitude which is also a great circle—that is, one whose plane passes through the center of the globe. The plane of Earth's equator, when projected outwards to the celestial sphere, defines the celestial equator. In the cycle of Earth's seasons, the equatorial plane runs through the Sun twice per year: on the equinoxes in March and September.
Equator | Overview
On the sphere the normal passes through the centre and the latitude () is therefore equal to the angle subtended at the centre by the meridian arc from the equator to the point concerned. If the meridian distance is denoted by then where denotes the mean radius of the Earth. is equal to . No higher accuracy is appropriate for since higher-precision results necessitate an ellipsoid model. With this value for the meridian length of 1 degree of latitude on the sphere is (60.0 nautical miles). The length of 1 minute of latitude is (1.00 nautical miles), while the length of 1 second of latitude is (see nautical mile).
Latitude | Meridian distance on the sphere
Following Marinos, he assigned coordinates to all the places and geographic features he knew, in a grid that spanned the globe. Latitude was measured from the equator, as it is today, but Ptolemy preferred to express it as "climata", the length of the longest day rather than degrees of arc: the length of the midsummer day increases from 12h to 24h as one goes from the equator to the polar circle. In books 2 through 7, he used degrees and put the meridian of 0 longitude at the most western land he knew, the "Blessed Islands", often identified as the Canary Islands, as suggested by the location of the six dots labelled the "FORTUNATA" islands near the left extreme of the blue sea of Ptolemy's map here reproduced.
Ptolemy | The "Geography"
On the GRS80 or WGS84 spheroid at sea level at the Equator, one latitudinal second measures 30.715 meters, one latitudinal minute is 1843 meters and one latitudinal degree is 110.6 kilometers. The circles of longitude, meridians, meet at the geographical poles, with the west–east width of a second naturally decreasing as latitude increases. On the Equator at sea level, one longitudinal second measures 30.92 meters, a longitudinal minute is 1855 meters and a longitudinal degree is "111.3 kilometers. At 30° a longitudinal second is 26.76 meters, at Greenwich (51°28′38″N) 19.22 meters, and at 60° it is 15.42 meters. On the WGS84 spheroid, the length in meters of a degree of latitude at latitude φ (that is, the number of meters you would have to travel along a north–south line to move 1 degree in latitude, when at latitude φ), is about The returned measure of meters per degree latitude varies continuously with latitude.
Geographic coordinate system | Length of a degree
Planes parallel to the equatorial plane intersect the surface in circles of constant latitude; these are the parallels. The Equator has a latitude of 0°, the North Pole has a latitude of 90° North (written 90° N or +90°), and the South Pole has a latitude of 90° South (written 90° S or −90°). The latitude of an arbitrary point is the angle between the equatorial plane and the normal to the surface at that point: the normal to the surface of the sphere is along the radius vector. The latitude, as defined in this way for the sphere, is often termed the spherical latitude, to avoid ambiguity with the geodetic latitude and the auxiliary latitudes defined in subsequent sections of this article.
Latitude | The graticule on the sphere
The continent spanned from 85° N to 90° S. Pangea was centered over the equator, and encompassed area from the North to the South poles. The Southeastern part of present-day North America and the Northern region of current day Africa intersected the equator. Present-day Eastern Asia was furthest North and Antarctica and Australia were furthest South.
Paleocontinent | Location
For example, on a GEOREF chart, Naval Air Station Patuxent River (38°17′10″N 76°24′42″W) / (38.286108, -76.4291704) is located (to the nearest minute) at position GJPJ3417. To locate the position from the coordinates, proceed as follows: The same co-ordinate shown in 6-digit (1/10 minute) format is GJPJ342171 and in 8-digit (1/100 minute) format is GJPJ34241716.
World Geographic Reference System | Example
The 60th parallel north or south is half as long as the Equator (disregarding Earth's minor flattening by 0.3%). A circle of latitude is perpendicular to all meridians. The latitude of the circle is approximately the angle between the Equator and the circle, with the angle's vertex at Earth's centre. The Equator is at 0°, and the North Pole and South Pole are at 90° north and 90° south, respectively. The Equator is the longest circle of latitude and is the only circle of latitude which also is a great circle.
Circle of latitude | Introduction
The monument consists of four iron wood poles, each with a diameter of about 0,30 metre, with frontage bollard height is two pieces as high as 3,05 radian place backside bollard and the signpost dart as high as 4,40 metres.
The Equator monument | Construction
It was located 1'.6 west and 0'.7 north of the nucleus.
IC 5201 | Introduction
A (geographic) meridian (or line of longitude) is the half of an imaginary great circle on the Earth's surface, terminated by the North Pole and the South Pole, connecting points of equal longitude, as measured in angular degrees east or west of the Prime Meridian. The position of a point along the meridian is given by that longitude and its latitude, measured in angular degrees north or south of the Equator. Each meridian is perpendicular to all circles of latitude. Meridians are half of a great circle on the Earth's surface. The length of a meridian on a modern ellipsoid model of the earth (WGS 84) has been estimated at 20,003.93 km (12,429.9 miles) .
Meridian (geography) | Introduction
Latitude: 20°15'29.9"N Longitude: 73°30'11.3"E Height from mean sea level: 700m
Peint | Location
This ecological conclusion matches the previous paleomagnetic findings which confirms this equatorial location.
Laurentia | Equatorial location
He even quantifies his statement: "When the great circle distances which are to be measured in the vicinity of the equator do not exceed 20 degrees of a great circle, or 15 degrees near Spain and France, or 8 and even 10 degrees in northern parts it is convenient to use rhumb line distances". For a ruler measurement of a "short" line, with midpoint at latitude "φ", where the scale factor is "k" = sec "φ" = :
Mercator projection | Formulae for distance
As of 2010, it is located at an angular separation of 0.1843 arcseconds along a position angle of 135.1°. They orbit each other with an estimated period of 201 years and a semimajor axis of 0.45 arcseconds.
89 Aquarii | Introduction
It is currently at 35.8 AU from the Sun, near its perihelion.
(230965) 2004 XA192 | Introduction
It is located between latitudes 575 and 590 north of the equator, longitudes 975 east of the Greenwich meridian, and at the transition between the equatorial forest in the south and the savannah to the north.
Batibo | Introduction
In the equatorial coordinate system, for equinox and equator of 1950.0, the north galactic pole is defined at right ascension , declination +27.4°, in the constellation Coma Berenices, with a probable error of ±0.1°. Longitude 0° is the great semicircle that originates from this point along the line in position angle 123° with respect to the equatorial pole. The galactic longitude increases in the same direction as right ascension. Galactic latitude is positive towards the north galactic pole, with a plane passing through the Sun and parallel to the galactic equator being 0°, whilst the poles are ±90°. Based on this definition, the galactic poles and equator can be found from spherical trigonometry and can be precessed to other epochs; see the table.
Galactic coordinate system | Definition
Similarly sec 2.56° = 1.001, so a strip of width 5.12° (centred on the equator) is accurate to within 0.1% or 1 part in 1,000. Therefore, the Mercator projection is adequate for mapping countries close to the equator.
Mercator projection | Accuracy
In astronomy, the meridian is the great circle passing through the celestial poles, as well as the zenith and nadir of an observer's location. Consequently, it contains also the north and south points on the horizon, and it is perpendicular to the celestial equator and horizon. Meridians, celestial and terrestrial, are determined by the axial-pencil of planes passing through the axis of Earth's rotation. For a location "not" at a geographical pole there is a unique plane in this axial-pencil through that location. The intersection of this plane with Earth's surface is the geographical meridian, and the intersection of the plane with the celestial sphere is the celestial meridian for that location and time.
Meridian (astronomy) | Introduction
In right-handed rectangular equatorial coordinates (where the formula_18 axis is in the direction of the vernal point, and the formula_19 axis is 90° to the east, in the plane of the celestial equator, and the formula_20 axis is directed toward the north celestial pole ), in astronomical units:
Position of the Sun | Rectangular equatorial coordinates
The graticule is formed by the lines of constant latitude and constant longitude, which are constructed with reference to the rotation axis of the Earth. The primary reference points are the poles where the axis of rotation of the Earth intersects the reference surface. Planes which contain the rotation axis intersect the surface at the meridians; and the angle between any one meridian plane and that through Greenwich (the Prime Meridian) defines the longitude: meridians are lines of constant longitude. The plane through the centre of the Earth and perpendicular to the rotation axis intersects the surface at a great circle called the Equator.
Latitude | The graticule on the sphere
Based on data obtained by Tufiño, it was believed that the equator passed through those two sites. However, according to readings based on the World Geodetic System WGS84, used in modern GPS systems and GIS products, the equator actually lies about north of the marked line. Over the years, countless tourists have had their pictures taken straddling the line drawn down the center of the east-facing staircase and across the plaza. The pyramidal monument, with each side facing a cardinal direction is topped by a globe which is in diameter and weighs . Inside the monument is a small museum that displays a variety of indigenous items pertaining to Ecuadorian culture: clothing, descriptions of the various ethnic groups, and examples of their activities.
Ciudad Mitad del Mundo | Latitude discrepancy
On Earth, starting at the North Pole and heading south to the South Pole, the IERS Reference Meridian (as of 2016) passes through:
Prime meridian | List of places
The 24th parallel south is a circle of latitude that is 24 degrees south of the Earth's equatorial plane, about 60 km south of the Tropic of Capricorn. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America.
24th parallel south | Introduction
In modern units this is , close to the current equatorial value of .
Spherical Earth | India
This is a list of the extreme points of Equatorial Guinea, the points that are farther north, south, east or west than any other location.
Geography of Equatorial Guinea | Extreme points
The 45th parallel south is a circle of latitude that is 45° south of the Earth's equator. It is the line that marks the theoretical halfway point between the equator and the South Pole. The true halfway point is south of this parallel because Earth is not a perfect sphere, but bulges at the equator and is flattened at the poles. Unlike its northern counterpart, almost all (97%) of it passes through open ocean. It crosses the South Atlantic Ocean, the Indian Ocean, Australasia (New Zealand and just south of Tasmania), the Southern Ocean, and Patagonia. At this latitude, daytime lasts for 15 hours, 37 minutes during the December solstice and 8 hours, 46 minutes during the June solstice.
45th parallel south | Introduction
Earth's location in the Universe
Outline of Earth | Location of Earth
He therefore would have estimated the circumference of the Earth to be about at the equator and at 30 degrees north (around where he was sailing), whereas the correct value is at the equator and at 30 degrees north.
Christopher Columbus | Geographical considerations
The equator passes through the land of 11 countries. Indonesia is the country straddling the greatest length of the equatorial line across both land and sea. Starting at the Prime Meridian and heading eastwards, the equator passes through: Despite its name, no part of Equatorial Guinea lies on the equator. However, its island of Annobón is south of the equator, and the rest of the country lies to the north.
Equator | Equatorial countries and territories
The 31st parallel south is a circle of latitude that is 31 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America. At this latitude the sun is visible for 14 hours, 13 minutes during the December solstice and 10 hours, 04 minutes during the June solstice.
31st parallel south | Introduction
As the observer moves north (or south), the celestial equator tilts towards the opposite horizon. The celestial equator is defined to be infinitely distant (since it is on the celestial sphere); thus, the ends of the semicircle always intersect the horizon due east and due west, regardless of the observer's position on Earth. At the poles, the celestial equator coincides with the astronomical horizon. At all latitudes, the celestial equator is a uniform arc or circle because the observer is only finitely far from the plane of the celestial equator, but infinitely far from the celestial equator itself. Astronomical objects near the celestial equator appear above the horizon from most places on earth, but they culminate (reach the meridian) highest near the equator.
Celestial equator | Introduction
He put the meridian of 0 longitude at the most western land he knew, the Canary Islands. "Geographia" indicated the countries of "Serica" and "Sinae" (China) at the extreme right, beyond the island of "Taprobane" (Sri Lanka, oversized) and the "Aurea Chersonesus" (Southeast Asian peninsula).
Spherical Earth | Claudius Ptolemy
When the Sun is directly above the Earth's Equator (on the equinoxes of approximately March 20 and September 23), sunlight shines perpendicular to the Earth's axis of rotation, and all latitudes have a 12-hour day and 12-hour night. On and near the Equator sunlight comes from almost directly above every day year-round, and thus the Equator has a rather stable daytime temperature the whole year.
Equator | Introduction
This is then subtracted from 90° to obtain the angular distance from the position directly above to obtain the zenith distance. A further correction must then be taken into account to counter the "wobble" of the earth's spin and rotation relative to the sun and planets. This is given in the declination for the body on a particular day in the year (also taken from the nautical almanac). If the declination of the body is in the opposite hemisphere (ie if you are in the northern hemisphere and the declination is in the southern hemisphere) then the declination must be subtracted from your true zenith distance, otherwise the declination is added.
Meridian altitude | Methodology
The celestial equator is the great circle of the imaginary celestial sphere on the same plane as the equator of Earth. This plane of reference bases the equatorial coordinate system. In other words, the celestial equator is an abstract projection of the terrestrial equator into outer space. Due to Earth's axial tilt, the celestial equator is currently inclined by about 23.44° with respect to the ecliptic (the plane of Earth's orbit). The inclination has varied from about 22.0° to 24.5° over the past 5 million years. An observer standing on Earth's equator visualizes the celestial equator as a semicircle passing through the zenith, the point directly overhead.
Celestial equator | Introduction
The "latitude" (abbreviation: Lat., φ, or phi) of a point on Earth's surface is the angle between the equatorial plane and the straight line that passes through that point and through (or close to) the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the Equator and to each other. The North Pole is 90° N; the South Pole is 90° S. The 0° parallel of latitude is designated the Equator, the fundamental plane of all geographic coordinate systems. The Equator divides the globe into Northern and Southern Hemispheres.
Geographic coordinate system | Latitude and longitude
The 23rd parallel south is a circle of latitude that is 23 degrees south of the Earth's equatorial plane, about 50 km north of the Tropic of Capricorn. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America.
23rd parallel south | Introduction
There were some variations. When he noted the sight line for the True Meridian from his family's house to the depot, he could check the declination of his compass before and after surveying throughout the day. He noted this variation down.
Meridian (geography) | True meridian
Geographic coordinates expressed in WGS 84.
Extreme points of South America | Latitude and longitude
The figure illustrates the Tissot indicatrix for this projection. On the equator h=k=1 and the circular elements are undistorted on projection. At higher latitudes the circles are distorted into an ellipse given by stretching in the parallel direction only: there is no distortion in the meridian direction. The ratio of the major axis to the minor axis is formula_58. Clearly the area of the ellipse increases by the same factor.
Scale (map) | The equirectangular projection
This is different from the International Celestial Reference System (ICRS): the mean equator and equinox at J2000.0 are distinct from and of lower precision than ICRS, but agree with ICRS to the limited precision of the former. Use of the "mean" locations means that nutation is averaged out or omitted. This means that the Earth's rotational North pole does not point quite at the J2000 celestial pole at the epoch J2000.0; the true pole of epoch nutates away from the mean one. The same differences pertain to the equinox.
Equinox (celestial coordinates) | J2000.0
In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −17.41° and −37.29°.
Pyxis | Characteristics
The 25th parallel south is a circle of latitude that is 25 degrees south of the Earth's equatorial plane, just south of the Tropic of Capricorn. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America.
25th parallel south | Introduction
The 35th parallel south is a circle of latitude that is 35 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, Australasia, the Pacific Ocean and South America. At this latitude the sun is visible for 14 hours, 31 minutes during the December solstice and 9 hours, 48 minutes during the June solstice.
35th parallel south | Introduction
The 32nd parallel south is a circle of latitude that is 32 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America. At this latitude the sun is visible for 14 hours, 19 minutes during the December solstice and 9 hours, 58 minutes during the June solstice.
32nd parallel south | Introduction
Toward the ending of the 12th century there were two main locations that were acknowledged as the geographic location of the meridian, France and Britain. These two locations often conflicted and a settlement was reached only after there was an International Meridian Conference held, in which Greenwich was recognized as the 0° location. The meridian through Greenwich (inside Greenwich Park), England, called the Prime Meridian, was set at zero degrees of longitude, while other meridians were defined by the angle at the center of the earth between where it and the prime meridian cross the equator. As there are 360 degrees in a circle, the meridian on the opposite side of the earth from Greenwich, the antimeridian, forms the other half of a circle with the one through Greenwich, and is at 180° longitude near the International Date Line (with land mass and island deviations for boundary reasons).
Meridian (geography) | Geographic
Latitude is a geographical term denoting the north–south angular location of a place on the Earth or other celestial bodies. Latitude may also refer to:
Latitude (disambiguation) | Introduction
Only accurate Mercator projections of regions near the equator will necessitate the ellipsoidal corrections.
Mercator projection | Generalization to the ellipsoid
The 12th parallel south is a circle of latitude that is 12 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America.
12th parallel south | Introduction
The 33rd parallel south is a circle of latitude that is 33 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America.
33rd parallel south | Introduction
The telescope's Sheepshanks dome was in between the later Great Equatorial Building and the prime Meridian. The focal length of the telescope is about 1.9 meters (6.2 feet) in one source, and another says 8 feet 2 inches. The telescope tube was made of wood.
Sheepshanks equatorial | Introduction
"C. equatoriana" is found in Costa Rica, Panama, Colombia, and Ecuador.
Clelia equatoriana | Geographic range
It is located about 5500 light years away from Earth.
NGC 6357 | Introduction
The length of a degree of longitude (east-west distance) depends only on the radius of a circle of latitude. For a sphere of radius that radius at latitude is , and the length of a one-degree (or radian) arc along a circle of latitude is When the Earth is modelled by an ellipsoid this arc length becomes where , the eccentricity of the ellipsoid, is related to the major and minor axes (the equatorial and polar radii respectively) by An alternative formula is Cos decreases from 1 at the equator to 0 at the poles, which measures how circles of latitude shrink from the equator to a point at the pole, so the length of a degree of longitude decreases likewise.
Longitude | Length of a degree of longitude
A straight line on the Mercator map at angle "α" to the meridians is a rhumb line. When "α" = or the rhumb corresponds to one of the parallels; only one, the equator, is a great circle. When "α" = 0 or it corresponds to a meridian great circle (if continued around the Earth). For all other values it is a spiral from pole to pole on the globe intersecting all meridians at the same angle, and is thus not a great circle. This section discusses only the last of these cases. If "α" is neither 0 nor then the above figure of the infinitesimal elements shows that the length of an infinitesimal rhumb line on the sphere between latitudes "φ"; and "φ" + "δφ" is "a" sec "α" "δφ".
Mercator projection | On a rhumb
The 61st parallel south is a circle of latitude that is 61 degrees south of the Earth's equatorial plane. No land lies on the parallel — it crosses nothing but the Southern Ocean. At this latitude the sun is visible for 19 hours, 16 minutes during the December solstice and 5 hours, 32 minutes during the June solstice.
61st parallel south | Introduction
The two hottest places on the equator are therefore at longitudes 0° W and 180° W, and the coolest points on the equator are at longitudes 90° W and 270° W. However, the "MESSENGER" project uses an east-positive convention.
Mercury (planet) | Longitude convention
The "longitude" (abbreviation: Long., λ, or lambda) of a point on Earth's surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses (often called great circles), which converge at the North and South Poles. The meridian of the British Royal Observatory in Greenwich, in southeast London, England, is the international prime meridian, although some organizations—such as the French Institut Géographique National—continue to use other meridians for internal purposes. The prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side.
Geographic coordinate system | Latitude and longitude
The trilinear coordinates of the Exeter point are
Exeter point | Trilinear coordinates
Along the equator, consecutive swaths are separated by 2,800 km. QuikSCAT orbits Earth at an altitude of 802 km and at a speed of about 7 km per second.
QuikSCAT | Instrument description
The maps shown here are based on this relationship; they show a Lambert azimuthal equal-area projection of the Earth, in yellow, overlaid on which is another map, in blue, shifted horizontally by 180° of longitude and inverted about the Equator with respect to latitude. Noon at one place is midnight at the other (ignoring daylight saving time and irregularly shaped time zones) and, with the exception of the tropics, the longest day at one point corresponds to the shortest day at the other, and midwinter at one point coincides with midsummer at the other. Sunrise and sunset do not quite oppose each other at antipodes due to refraction of sunlight.
Antipodes | Geography
The 12th parallel north is a circle of latitude that is 12 degrees north of the Earth's equatorial plane. It crosses Africa, the Indian Ocean, South Asia, Southeast Asia, the Pacific Ocean, Central America, South America and the Atlantic Ocean. At this latitude the sun is visible for 12 hours, 50 minutes during the summer solstice and 11 hours, 25 minutes during the winter solstice.
12th parallel north | Introduction
Located in the southern Pacific Ocean, west south west of Guaitecas in Chile, and north of Antarctica, has an ocean floor depth of below sea level.
45×90 points | 45°S, 90°W
The 13th parallel north is a circle of latitude that is 13 degrees north of the Earth's equatorial plane. It crosses Africa, Asia, the Indian Ocean, the Pacific Ocean, Central America, the Caribbean and the Atlantic Ocean. At this latitude the sun is visible for 12 hours, 53 minutes during the summer solstice and 11 hours, 22 minutes during the winter solstice.
13th parallel north | Introduction
The 11th parallel south is a circle of latitude that is 11 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America.
11th parallel south | Introduction
The name is derived from medieval Latin word "aequator", in the phrase "circulus aequator diei et noctis," meaning 'circle equalizing day and night', from the Latin word "aequare" meaning 'make equal'.
Equator | Etymology