Radius of the earth in metres

Approximating the figure of Earth by an Earth spheroidthe radius ranges from a maximum of nearly 6, km 3, mi equatorial radiusrepresented a to a minimum of nearly 6, km 3, mi polar radiusrepresented b.

Please provide values below to convert Earth's equatorial radius to meter [m], or vice versa. From: Earth's equatorial radius To: meter. Earth's Equatorial Radius to Kilometer. Earth's Equatorial Radius to Decimeter. Earth's Equatorial Radius to Centimeter.

Radius of the earth in metres

Approximating the figure of Earth by an Earth spheroid , the radius ranges from a maximum of nearly 6, km 3, mi equatorial radius , denoted a to a minimum of nearly 6, km 3, mi polar radius , denoted b. A nominal Earth radius is sometimes used as a unit of measurement in astronomy and geophysics , which is recommended by the International Astronomical Union to be the equatorial value. A globally-average value is usually considered to be 6, kilometres 3, mi with a 0. The International Union of Geodesy and Geophysics IUGG provides three reference values: the mean radius R 1 of three radii measured at two equator points and a pole; the authalic radius , which is the radius of a sphere with the same surface area R 2 ; and the volumetric radius , which is the radius of a sphere having the same volume as the ellipsoid R 3. Other ways to define and measure the Earth's radius involve the radius of curvature. A few definitions yield values outside the range between the polar radius and equatorial radius because they include local or geoidal topography or because they depend on abstract geometrical considerations. Earth's rotation , internal density variations, and external tidal forces cause its shape to deviate systematically from a perfect sphere. Our descriptions of Earth's surface must be simpler than reality in order to be tractable. Hence, we create models to approximate characteristics of Earth's surface, generally relying on the simplest model that suits the need. Each of the models in common use involve some notion of the geometric radius. Strictly speaking, spheres are the only solids to have radii, but broader uses of the term radius are common in many fields, including those dealing with models of Earth. The following is a partial list of models of Earth's surface, ordered from exact to more approximate:. In the case of the geoid and ellipsoids, the fixed distance from any point on the model to the specified center is called "a radius of the Earth" or "the radius of the Earth at that point".

Earth Radius in Specified Units. Standards history. Categories : Earth Planetary science Planetary geology.

The symbol R? The radius of our planet, The Earth, is the distance from the centre of the Earth to a point on or near its surface, and it ranges from nearly 6, km to nearly 6, km, approximating the figure of Earth by an Earth spheroid. Furthermore, in astronomy and geophysics, a nominal radius of earth is sometimes employed as a unit of measurement. The radius of curvature is another approach to define and measure the Earth radius, and some definitions produce results that are outside the range between polar and equatorial radius because they include local or geoidal topography. Another reason could be that they are based on abstract geometrical ideas. The radius of the Earth in miles is approximately 3, miles.

The calculator below calculates Earth radius at a given latitude. In fact, of course, it calculates the radius of WGS 84 reference ellipsoid at a given latitude, and if you want some theory recap, you can find it below the calculator. Since the Earth is flattened at the poles and bulges at the equator, geodesy represents Earth's shape with an oblate spheroid. The oblate spheroid, or oblate ellipsoid, is an ellipsoid of revolution obtained by rotating an ellipse about its shorter axis. It is the regular geometric shape that most nearly approximates the shape of the Earth. A spheroid describing the Earth's figure or other celestial body is called a reference ellipsoid.

Radius of the earth in metres

The crew of Apollo 17 took this photograph of Earth in December while their spacecraft was traveling between the Earth and the Moon. The orange-red deserts of Africa and Saudi Arabia stand in stark contrast to the deep blue of the oceans and the white of both clouds and snow-covered Antarctica. In B. Eratosthenes used Aristotle's idea that, if the Earth was round, distant stars in the night sky would appear at different positions to observers at different latitudes. Eratosthenes knew that on the first day of summer, the Sun passed directly overhead at Syene, Egypt. At midday of the same day, he measured the angular displacement of the Sun from overhead at the city of Alexandria - stadia away from Syene. He found that the angular displacement was 7. Thus the circumference can be estimated by multiplying the distance between the two cities, stadia, by 50, equaling , stadia.

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When identifying the position of an observable location, the use of more precise values for WGS radii may not yield a corresponding improvement in accuracy. The Magellan expedition — , which was the first circumnavigation of the World, soundly demonstrated the sphericity of the Earth, [30] and affirmed the original measurement of 40, km 25, mi by Eratosthenes. The Earth's meridional radius of curvature at the equator equals the meridian's semi-latus rectum :. Contents move to sidebar hide. Earth's Equatorial Radius to Millimeter. Regardless of the model, any of these geocentric radii falls between the polar minimum of about 6, km and the equatorial maximum of about 6, km 3, to 3, mi. Retrieved 18 November It is important to note that the Earth is not a perfect sphere but is an oblate spheroid, meaning it is slightly flattened at the poles and bulging at the equator due to its rotation. The Classical Journal. Its mass is estimated to be 5. Approximating the figure of Earth by an Earth spheroid , the radius ranges from a maximum of nearly 6, km 3, mi equatorial radius , denoted a to a minimum of nearly 6, km 3, mi polar radius , denoted b. Astronomical system of units.

Earth Radius by Latitude Calculator — Calculates radius and diameter of the Earth for a given latitude. Earth radius at sea level is

The first and second radii of curvature correspond, respectively, to the Earth's meridional and prime-vertical radii of curvature. Washington D. This difference is the geoid height , positive above or outside the ellipsoid, negative below or inside. See also: Quarter meridian and Rectifying latitude. Strictly speaking, spheres are the only solids to have radii, but broader uses of the term radius are common in many fields, including those dealing with models of Earth. There are two principal radii of curvature : along the meridional and prime-vertical normal sections. Standards history NGVD The Earth can be modeled as a sphere in many ways. Contents move to sidebar hide. Earth's Equatorial Radius to Roman Actus. May Open Mobile Search. Cross section of Earth's Interior. Eratosthenes was the first person to mathematically calculate the diameter of the earth by comparing the difference in the angle of the sun's rays at different geographic points during the 3rd century B. Eratosthenes was the first person to calculate the radius of the earth by comparing the difference in the angle of the sun's rays at different geographic points during the 3rd century B.