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29.7827 km/s[3]
(107218 km/h; 66622 mph)
−11.26064°[3] to J2000 ecliptic
Satellites1, the Moon
Physical characteristics
Mean radius
6371.0 km (3958.8 mi)[6]
Equatorial radius
6378.137 km (3963.191 mi)[7][8]
Polar radius
6356.752 km (3949.903 mi)[9]
Flattening1/298.257222101 (ETRS89)[10]
Total: 510072000 km2
(196940000 sq mi)[12][n 4]

Land: 148940000 km2
(57510000 sq mi) – 29.2%

Sidereal rotation period
0.99726968 d[16]
(23h 56m 4.100s)
Equatorial rotation velocity
0.4651 km/s[17]
(1674.4 km/h; 1040.4 mph)
Temperature287.91 K (14.76 °C; 58.57 °F) (blackbody temperature)[18]
Surface temp. min mean max
Celsius −89.2 °C[19] 14.76 °C[20] 56.7 °C[21]
Fahrenheit −128.5 °F 58.568 °F 134.0 °F
Surface equivalent dose rate0.274 μSv/h[22]
Surface pressure
101.325 kPa (at sea level)
Composition by volume
  • 78.08% nitrogen (N2; dry air)[3]
  • 20.95% oxygen (O2)
  • ~ 1% water vapor (climate variable)
  • 0.9340% argon
  • 0.0413% carbon dioxide[23]
  • 0.00182% neon[3]
  • 0.00052% helium
  • 0.00019% methane
  • 0.00011% krypton
  • 0.00006% hydrogen

Earth is the third

cosmic radiation

climate regions, and a range of weather phenomena such as precipitation, allowing components such as nitrogen to cycle

Earth is

light-minutes away from the Sun and orbits it, taking a year (about 365.25 days) to complete one revolution. The Earth rotates around its own axis in slightly less than a day (in about 23 hours and 56 minutes). The Earth's axis of rotation is tilted with respect to the perpendicular to its orbital plane around the Sun, producing seasons. Earth is orbited by one permanent natural satellite, the Moon, which orbits Earth at 384,400 km (1.28 light seconds) and is roughly a quarter as wide as Earth. Through tidal locking, the Moon always faces the Earth with the same side, which causes tides, stabilizes Earth's axis, and gradually slows its rotation

Earth, like most other bodies in the Solar System, formed 4.5 billion years ago from gas in the early Solar System. During the first billion years of Earth's history, the ocean formed and then life developed within it. Life spread globally and has been altering Earth's atmosphere and surface, leading to the Great Oxidation Event two billion years ago. Humans emerged 300,000 years ago, and reached a population of 8 billion on November 15, 2022. Humans depend on Earth's biosphere and natural resources for their survival, but have increasingly impacted the planet's environment. Humanity's current impact on Earth's climate and biosphere is unsustainable, threatening the livelihood of humans and many other forms of life, and causing widespread extinctions.[24]



Germanic paganism: late Norse mythology included Jörð ('Earth'), a giantess often given as the mother of Thor.[26]

Historically, earth has been written in lowercase. From

definite sense as "the globe" was expressed as the earth. By the era of Early Modern English, capitalization of nouns began to prevail, and the earth was also written the Earth, particularly when referenced along with other heavenly bodies. More recently, the name is sometimes simply given as Earth, by analogy with the names of the other planets, though earth and forms with the remain common.[25] House styles now vary: Oxford spelling recognizes the lowercase form as the most common, with the capitalized form an acceptable variant. Another convention capitalizes "Earth" when appearing as a name (for example, "Earth's atmosphere") but writes it in lowercase when preceded by the (for example, "the atmosphere of the earth"). It almost always appears in lowercase in colloquial expressions such as "what on earth are you doing?"[27]

Occasionally, the name Terra

Latin) like Italian and Portuguese, while in other Romance languages the word gave rise to names with slightly altered spellings (like the Spanish Tierra and the French Terre). The Latinate form Gæa or Gaea (English: /ˈ.ə/) of the Greek poetic name Gaia (Γαῖα; Ancient Greek[ɡâi̯.a] or [ɡâj.ja]) is rare, though the alternative spelling Gaia has become common due to the Gaia hypothesis, in which case its pronunciation is /ˈɡ.ə/ rather than the more classical English /ˈɡ.ə/.[30]

There are a number of adjectives for the planet Earth. From Earth itself comes earthly. From the Latin Terra comes terran /ˈtɛrən/,[31] terrestrial /təˈrɛstriəl/,[32] and (via French) terrene /təˈrn/,[33] and from the Latin Tellus comes tellurian /tɛˈlʊəriən/[34] and telluric.[35]

Natural history


The oldest material found in the Solar System is dated to 4.5682+0.0002

nebular theory, planetesimals formed by accretion, with the primordial Earth being estimated as likely taking anywhere from 70 to 100 million years to form.[38]

Estimates of the age of the Moon range from 4.5 Ga to significantly younger.

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.[40] It hit Earth with a glancing blow and some of its mass merged with Earth.[41][42] Between approximately 4.1 and 3.8 Ga, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment of the Moon and, by inference, to that of Earth.[43]

After formation

Pale orange dot artist's impression of the early Earth tinted orange by its methane-rich early atmosphere[44]

Earth's atmosphere and oceans were formed by volcanic activity and outgassing.[45] Water vapor from these sources condensed into the oceans, augmented by water and ice from asteroids, protoplanets, and comets.[46] Sufficient water to fill the oceans may have been on Earth since it formed.[47] In this model, atmospheric greenhouse gases kept the oceans from freezing when the newly forming Sun had only 70% of its current luminosity.[48] By 3.5 Ga, Earth's magnetic field was established, which helped prevent the atmosphere from being stripped away by the solar wind.[49]

As the molten outer layer of Earth cooled it

Ma after Earth's formation.[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. The two models and the data that support them can be reconciled by large-scale recycling of the continental crust, particularly during the early stages of Earth's history.[56]

New continental crust forms as a result of plate tectonics, a process ultimately driven by the continuous loss of heat from Earth's interior. Over the period of hundreds of millions of years, tectonic forces have caused areas of continental crust to group together to form supercontinents that have subsequently broken apart. At approximately 750 Ma, one of the earliest known supercontinents, Rodinia, began to break apart. The continents later recombined to form Pannotia at 600–540 Ma, then finally Pangaea, which also began to break apart at 180 Ma.[57]

The most recent pattern of

middle-latitude regions have since undergone repeated cycles of glaciation and thaw, repeating about every 21,000, 41,000 and 100,000 years.[60] The Last Glacial Period, colloquially called the "last ice age", covered large parts of the continents, to the middle latitudes, in ice and ended about 11,700 years ago.[61]

Origin of life and evolution

Artist's impression of the Archean, the eon after Earth's formation, featuring round stromatolites, which are early oxygen-producing forms of life from billions of years ago. After the Late Heavy Bombardment, Earth's crust had cooled, its water-rich barren surface is marked by continents and volcanoes, with the Moon still orbiting Earth half as close than today, appearing 2.8 times larger and producing strong tides.[62]

Western Greenland,[68] and remains of biotic material found in 4.1 billion-year-old rocks in Western Australia.[69][70] The earliest direct evidence of life on Earth is contained in 3.45 billion-year-old Australian rocks showing fossils of microorganisms.[71][72]

During the

civilization, led to humans having an influence on Earth and the nature and quantity of other life forms that continues to this day.[77]


fifth largest planetary sized and largest terrestrial object of the Solar System

Due to Earth's rotation it has the shape of an ellipsoid, bulging at its Equator, reaching 43 kilometers (27 mi) further out from its center of mass than at its poles.[86][87] Earth's shape furthermore has local

Chimborazo in Ecuador (6,384.4 km or 3,967.1 mi) is its farthest point out.[91][92]
Parallel to the rigid land topography the Ocean exhibits a more dynamic topography.[93]

To measure the local variation of Earth's topography, geodesy employs an idealized Earth producing a shape called a geoid. Such a geoid shape is gained if the ocean is idealized, covering Earth completely and without any perturbations such as tides and winds. The result is a smooth but gravitational irregular geoid surface, providing a mean sea level (MSL) as a reference level for topographic measurements.[94]