[245][268] It is estimated that global temperatures in the year 2020 were 1.2C (2.2F) warmer than the preindustrial baseline. [132][50] The most common rock constituents of the crust are oxides. These same latitudes also experience a midnight sun, where the sun remains visible all day. [182], Earth's co-orbital asteroids population consists of quasi-satellites, objects with a horseshoe orbit and trojans. This lower-density air then rises and is replaced by cooler, higher-density air. Earth Earth is 11.0x smaller than Jupiter DATE OF DISCOVERY Unknown Unknown DISCOVERED BY Known by the Ancients Known by the Ancients AVERAGE ORBIT DISTANCE 92,956,050 miles 483,638,564 miles MEAN ORBIT VELOCITY 66,622 mph 29,205 mph ORBIT ECCENTRICITY 0.01671123 0.04838624 EQUATORIAL INCLINATION 23.4393 degrees 3.1 degrees EQUATORIAL RADIUS [220] Earth's surface can be subdivided into specific latitudinal belts of approximately homogeneous climate. Photosynthesis provided a source of free oxygen, but the loss of reducing agents such as hydrogen is thought to have been a necessary precondition for the widespread accumulation of oxygen in the atmosphere. Earth is orbited by one permanent natural satellite, the Moon, which orbits Earth at 384,400km (1.28 light seconds) and is roughly a quarter as wide as Earth. Earth's surface is continually being shaped by internal plate tectonic processes including earthquakes and volcanism; by weathering and erosion driven by ice, water, wind and temperature; and by biological processes including the growth and decomposition of biomass into soil. [77], Earth's expected long-term future is tied to that of the Sun. For example, more than 1,300 Earths could fit inside Jupiter. [93], To measure the local variation of Earth's topography, geodesy employs an idealized Earth producing a shape called a geoid. Now, the circumference (C) of the tennis ball will be: C = D = 3.14 10 = 31.4 inches ", "How Are Fossil Fuels Extracted From the Ground? [168], In modern times, Earth's perihelion occurs around 3 January, and its aphelion around 4 July. [76][bettersourceneeded] This facilitated tool use and encouraged communication that provided the nutrition and stimulation needed for a larger brain, which led to the evolution of humans. [174] The same effect on the Moon has led to its tidal locking: its rotation period is the same as the time it takes to orbit Earth. Initial belief in a flat Earth was gradually displaced in Ancient Greece by the idea of a spherical Earth, which was attributed to both the philosophers Pythagoras and Parmenides. [26], Historically, earth has been written in lowercase. [216] Ocean heat content and currents are also important factors in determining climate, particularly the thermohaline circulation that distributes thermal energy from the equatorial oceans to the polar regions. Beneath the mantle, an extremely low viscosity liquid outer core lies above a solid inner core. Mars is much smaller than both Earth and Venus, with an equatorial radius of just 2,110 miles (3,396 km). ", "Atmospheric pressure as a natural climate regulator for a terrestrial planet with a biosphere", "The end of life on Earth is not the end of the world: converging to an estimate of life span of the biosphere? Example Consider a tennis ball whose great circle has a diameter of 10 inches. [205], The atmospheric pressure at Earth's sea level averages 101.325kPa (14.696psi),[206] with a scale height of about 8.5km (5.3mi). Earth is the densest planet in the solar system because of its metallic core and rocky mantle. Its diameter (the distance from one side to the other through Earth's center) is 7,926 miles (about 12,756 kilometers). These plumes can produce hotspots and flood basalts. At approximately 3Gyr, twice the present-day heat would have been produced, increasing the rates of mantle convection and plate tectonics, and allowing the production of uncommon igneous rocks such as komatiites that are rarely formed today. In theory, a solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten into a circumstellar disk, and then the planets grow out of that disk with the Sun. [255] Most of these states together form the United Nations, the leading worldwide intergovernmental organization,[256] which extends human governance over the ocean and Antarctica, and therefore all of Earth. Tim Sharp is the Reference Editor for Space.com. The development of agriculture, and then civilization, led to humans having an influence on Earth and the nature and quantity of other life forms that continues to this day. [64] This change enabled the proliferation of aerobic organisms and, indirectly, the formation of the ozone layer due to the subsequent conversion of atmospheric O2 into O3. During the summer, the day lasts longer, and the Sun climbs higher in the sky. [273] The standard astronomical symbols of Earth are a quartered circle, ,[274] representing the four corners of the world, and a globus cruciger, . [223] Atmospheric circulation also plays an important role: San Francisco and Washington DC are both coastal cities at about the same latitude. [137][138], The mean heat loss from Earth is 87mW m2, for a global heat loss of 4.421013W.[139] A portion of the core's thermal energy is transported toward the crust by mantle plumes, a form of convection consisting of upwellings of higher-temperature rock. It is thought possible to provide all basic physical needs globally within sustainable levels of resource use. Among the Solar System's planetary-sized objects Earth is the object with the highest density. Aphelion is 103.4% of the distance to perihelion. This polar motion has multiple, cyclical components, which collectively are termed quasiperiodic motion. Posidonius calculated the Earth's circumference by reference to the position of the star Canopus. [206] Water vapor content varies between 0.01% and 4%[206] but averages about 1%. that the stadion used by Posidonius was almost exactly 1/10 of a modern statute mile. To calculate it, follow these steps: Assume the height of your eyes to be h = 1.6 m. Build a right triangle with hypotenuse r + h (where r is Earth's radius) and a cathetus r. Calculate the last cathetus with Pythagora's theorem: the result is the distance to the horizon: a = [ (r + h) - r] What are the highest and lowest temperatures on Earth? At first, the moon may appear quite large, but that is only because it is our closest celestial body approximately 238,855. Additionally, the shadow of someone looking down a deep well at that time in Syene blocked the reflection of the Sun on the water. Earth, the third planet from the sun, is the fifth-largest planet in the solar system; only the gas giants Jupiter, Saturn, Uranus and Neptune are bigger. [1] Measurement of Earth's circumference has been important to navigation since ancient times. Density increases with depth, as described in the table on the right. James Webb Space Telescope spots 3 candidates, Truly to open 1st zero-gravity hard seltzer bar aboard astronaut training aircraft. This is because the Earth is an oblate spheroid, which means that it is slightly flattened at the poles and bulges at the equator. [25] This is why the polar circumference of the Earth is actually 40,008 kilometres, instead of 40,000. In each instance, winter occurs simultaneously in the opposite hemisphere. Its speed could tell us, Do fabled 'dark stars' actually exist? Without this tilt, there would be an eclipse every two weeks, alternating between lunar eclipses and solar eclipses. While Earth's land is also covered by considerable amounts of water, predominantly in the form of large sheets of ice covering polar land, containing more water than Earth's groundwater, lakes, rivers and atmospheric water together, most of Earth's land though is covered by vegetation. [186], As of September2021[update], there are 4,550 operational, human-made satellites orbiting Earth. Orbit Size Around Sun. [209] Other atmospheric functions important to life include transporting water vapor, providing useful gases, causing small meteors to burn up before they strike the surface, and moderating temperature. Notes on the factsheets - definitions of parameters, units, notes on sub- and superscripts, etc. Because unfixed hydrogen has a low molecular mass, it can achieve escape velocity more readily, and it leaks into outer space at a greater rate than other gases. [51] There are two main models of how this initial small volume of continental crust evolved to reach its current abundance:[52] (1) a relatively steady growth up to the present day,[53] which is supported by the radiometric dating of continental crust globally and (2) an initial rapid growth in the volume of continental crust during the Archean, forming the bulk of the continental crust that now exists,[54][55] which is supported by isotopic evidence from hafnium in zircons and neodymium in sedimentary rocks. Almost all of Earth's water is contained in its global ocean, spanning 70.8% of Earth's surface. Its equatorial radius is 6378 km, but its polar radius is 6357 km - in other words, the Earth is slightly flattened. Enabled by science, particularly Earth observation,[281] humans have started to take action on environmental issues globally,[282] acknowledging the impact of humans and the interconnectedness of Earth's environments. [257] Those termed non-renewable resources, such as fossil fuels, are only replenished over geological timescales. Is It the Earliest Surviving Instance of Spherical Cartography? [213] Three-quarters of the atmosphere's mass is contained within the first 11km (6.8mi) of the surface; this lowest layer is called the troposphere. It almost always appears in lowercase in colloquial expressions such as "what on earth are you doing? [225], Water vapor generated through surface evaporation is transported by circulatory patterns in the atmosphere. Regardless, this length became the French standard and was progressively adopted by other countries in Europe. Land can be covered by surface water, snow, ice, artificial structures or vegetation. [161][n 10] This is the maximum distance at which Earth's gravitational influence is stronger than the more distant Sun and planets. Since the second half of the 20th century, some hundreds of humans have temporarily stayed beyond Earth, a tiny fraction of whom have reached another celestial body, the Moon.[252][253]. The ozone layer blocks ultraviolet solar radiation, permitting life on land. In other words, if you could drive your car around the equator of the Earth. At the other extreme, the slowest-moving plate is the South American Plate, progressing at a typical rate of 10.6mm/a (0.42in/year). Earth's surface is the boundary between the atmosphere, and the solid Earth and oceans. However, things are more complicated than this since Earth is not a perfect sphere. As a red giant, the Sun will lose roughly 30% of its mass, so, without tidal effects, Earth will move to an orbit 1.7AU (250millionkm; 160millionmi) from the Sun when the star reaches its maximum radius, otherwise, with tidal effects, it may enter the Sun's atmosphere and be vaporized.[78]. [125], Earth's interior, like that of the other terrestrial planets, is divided into layers by their chemical or physical (rheological) properties. [176] Due to their tidal interaction, the Moon recedes from Earth at the rate of approximately 38mm/a (1.5in/year). Based on Government Sponsored Research NAS7-03001 and NNN12AA01C. ", "Curious Kids: Why is the moon called the moon? Measured around the Equator, it is 40,075.017 km (24,901.461 mi). Originating from earlier primates in eastern Africa 300,000 years ago humans have since been migrating and with the advent of agriculture in the 10th millennium BC increasingly settling Earth's land. Follow Tim on Google+ and @therealtimsharp, more than 1,300 Earths could fit inside Jupiter, Everything we know about Blue Beetle: Release date, plot, cast & more, Stonehenge's summer solstice orientation is seen in monuments all over the UK in amazing photos, Star Wars: Visions season 2 episodes, ranked, Out of this world accommodation: What sci-fi gets right (and wrong) about life beyond Earth, Transformers movies in order: Chronological and release, Virtual Nightmare is the anti-Matrix movie you've never seen, The summer meteor showers of 2023 could be awesome. [71][72], During the Neoproterozoic, 1000 to 539Ma, much of Earth might have been covered in ice. Its diameter (the distance from one side to the other through Earth's center) is 7,926 miles (about 12,756 kilometers). It is designated by the symbol . [36] By 4.540.04Ga the primordial Earth had formed. Around that time British mathematician Edmund Gunter improved navigational tools including a new quadrant to determine latitude at sea. These differences arise because the . The distance between the north and south poles is approximately 7900 miles while the equatorial . For comparison, the total surface area of Venus is roughly 178 million square miles (460 million square km) , and that of Mars is about 56 million square miles (144 million square km). Earth rotates around its own axis in slightly less than a day (in about 23 hours and 56 minutes). [185] The tiny near-Earth asteroid 2006 RH120 makes close approaches to the EarthMoon system roughly every twenty years. . Earth has a rounded shape, through hydrostatic equilibrium,[85] with an average diameter of 12,742 kilometers (7,918mi), making it the fifth largest planetary sized and largest terrestrial object of the Solar System. The Moon For information on the Moon, see the Moon Fact Sheet. [208], Earth's biosphere has significantly altered its atmosphere. Models predict that the Sun will expand to roughly 1AU (150millionkm; 93millionmi), about 250 times its present radius. [195][196], In Earth's coldest regions, snow survives over the summer and changes into ice. For modern definitions and measurements, see, Historical use in the definition of units of measurement, History of the metre Meridional definition, "Astronomy 101 Specials: Eratosthenes and the Size of the Earth", "How did Eratosthenes measure the circumference of the earth? Earth's shape furthermore has local topographic variations. As explained by Cleomedes, Posidonius observed Canopus on but never above the horizon at Rhodes, while at Alexandria he saw it ascend as far as .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}7+12 degrees above the horizon (the meridian arc between the latitude of the two locales is actually 5 degrees 14 minutes). Scientific investigation has resulted in several culturally transformative shifts in people's view of the planet. Carl Sagan demonstrates how Eratosthenes determined that the Earth was round and the approximate circumference, https://en.wikipedia.org/w/index.php?title=Earth%27s_circumference&oldid=1156653234, Cleomedes assumes that the distance between Syene and Alexandria was 5,000, He assumes the simplified (but inaccurate) hypothesis that Syene was precisely on the. He has a journalism degree from the University of Kansas. [204] Despite some moons showing signs of large reservoirs of extraterrestrial liquid water, with possibly even more volume than Earth's ocean, all of them are large bodies of water under a kilometers thick frozen surface layer. [15] In 2012, Anthony Abreu Mora repeated Eratosthenes's calculation with more accurate data; the result was 40,074km, which is 66km different (0.16%) from the currently accepted polar circumference. [20], Around AD 830, Caliph Al-Ma'mun commissioned a group of Muslim astronomers led by Al-Khwarizmi to measure the distance from Tadmur (Palmyra) to Raqqa, in modern Syria. [224] Finally, temperatures decrease with height causing mountainous areas to be colder than low-lying areas. San Francisco's climate is significantly more moderate as the prevailing wind direction is from sea to land. According to space.com,(which is the source Google uses) the earth's circumference is 24,901 miles. Through tidal locking, the Moon always faces Earth with the same side, which causes tides, stabilizes Earth's axis, and gradually slows its rotation. The orbital and axial planes are not precisely aligned: Earth's axis is tilted some 23.44 degrees from the perpendicular to the EarthSun plane (the ecliptic), and the Earth-Moon plane is tilted up to 5.1 degrees against the EarthSun plane. New York, [14] A value for the stadion of 157.7metres has even been posited by L.V. Would you need to. [261] These metals and other elements are extracted by mining, a process which often brings environmental and health damage. Gunter used Snellius's circumference to define a nautical mile as 6,080 feet, the length of one minute of arc at 48 degrees latitude.[24]. Nevertheless, based on a map by Toscanelli, he chose to believe that the Earth's circumference was 25% smaller. [228][229], The upper atmosphere, the atmosphere above the troposphere,[230] is usually divided into the stratosphere, mesosphere, and thermosphere. Earth's name in English, the international language of . A nebula contains gas, ice grains, and dust (including primordial nuclides). Using those measurements, the equatorial circumference of Earth is about 24,901 miles (40,075 km). [241], Extreme weather, such as tropical cyclones (including hurricanes and typhoons), occurs over most of Earth's surface and has a large impact on life in those areas. It is the largest moon in the Solar System relative to the size of its planet, although Charon is larger relative to the dwarf planet Pluto. The Latinate form Ga or Gaea (English: /di./) of the Greek poetic name Gaia (; Ancient Greek:[i.a] or [j.ja]) is rare, though the alternative spelling Gaia has become common due to the Gaia hypothesis, in which case its pronunciation is /a./ rather than the more classical English /e./. [248] Most of the growth is expected to take place in sub-Saharan Africa. [111][112] Earth has an estimated 16.7millionkm2 (6.4millionsqmi) of cropland and 33.5millionkm2 (12.9millionsqmi) of pastureland. Pliny, for example, has quoted a value of 252,000 stadia. [2] Thus the sidereal day is shorter than the stellar day by about 8.4ms.[157], Apart from meteors within the atmosphere and low-orbiting satellites, the main apparent motion of celestial bodies in Earth's sky is to the west at a rate of 15/h = 15'/min. [128] The thickness of the crust varies from about 6 kilometers (3.7mi) under the oceans to 3050km (1931mi) for the continents. Nevertheless, Earth's hydrosphere also consists of water in the atmosphere and on land, including clouds, inland seas, lakes, rivers, and underground waters down to a depth of 2,000m (6,600ft). [270][271] As of 2018, no country meets the basic needs of its population without transgressing planetary boundaries. Images of Earth taken from space, particularly during the Apollo program, have been credited with altering the way that people viewed the planet that they lived on, called the overview effect, emphasizing its beauty, uniqueness and apparent fragility. At the equator of the magnetic field, the magnetic-field strength at the surface is 3.05105 T, with a magnetic dipole moment of 7.791022 Am2 at epoch 2000, decreasing nearly 6% per century (although it still remains stronger than its long time average). These plates are rigid segments that move relative to each other at one of three boundaries types: at convergent boundaries, two plates come together; at divergent boundaries, two plates are pulled apart; and at transform boundaries, two plates slide past one another laterally. [279][280] In particular, this caused a realization of the scope of effects from human activity on Earth's environment. The land surface includes many islands around the globe, but most of the land surface is taken by the four continental landmasses, which are (in descending order): Africa-Eurasia, America (landmass), Antarctica, and Australia (landmass). [39] A leading hypothesis is that it was formed by accretion from material loosed from Earth after a Mars-sized object with about 10% of Earth's mass, named Theia, collided with Earth. The terrain of the land surface varies greatly and consists of mountains, deserts, plains, plateaus, and other landforms. The calculator below calculates Earth radius at a given latitude. Instead, most of the hydrogen loss comes from the destruction of methane in the upper atmosphere.[236]. A half billion years later, the last common ancestor of all current life arose. [citation needed] Thus Posidonius's measure of 240,000 stadia translates to 24,000mi (39,000km), not much short of the actual circumference of 24,901mi (40,074km). When measured around the equator, the circumference of the Earth is 40.075 million meters. Compared to today's accepted measurement of the Earth's circumference of 24,901 miles, Eratosthenes' calculation is off by less than 1%. Mathematical Association of America", "The Eratosthenes-Strabo Nile Map. It is about 20light-years above the galactic plane in the Orion Arm. [3][16], Around AD 525, the Indian mathematician and astronomer Aryabhata wrote Aryabhatiya, in which he calculated the diameter of earth to be of 1,050 yojanas. At the same time, the upwelling of mantle material at divergent boundaries creates mid-ocean ridges. Since he thought Rhodes was 5,000 stadia due north of Alexandria, and the difference in the star's elevation indicated the distance between the two locales was 1/48 of the circle, he multiplied 5,000 by 48 to arrive at a figure of 240,000 stadia for the circumference of the earth. [210] This last phenomenon is the greenhouse effect: trace molecules within the atmosphere serve to capture thermal energy emitted from the surface, thereby raising the average temperature. Eratosthenes: "I dunno." He did not know, but like any good mathematician and scientist, he intended to find out using his available resources. [275] The Gaia hypothesis, developed in the mid-20th century, compared Earth's environments and life as a single self-regulating organism leading to broad stabilization of the conditions of habitability.[276][277][278]. The remaining 29.2% are land, which consists mainly of continential landmasses mostly on Earth's land hemisphere. Earth's circumference is the distance around Earth. Human population virtually completely remains on Earth's surface, fully depending on Earth and the environment it sustains.