File Name: earth facts and information .zip
NCBI Bookshelf. National Academy of Sciences US. The term "evolution" usually refers to the biological evolution of living things.
The Solar System
Earth is the third planet from the Sun and the only astronomical object known to harbor life. Much of Earth's polar regions are covered in ice. Earth's outer layer is divided into several rigid tectonic plates that migrate across the surface over many millions of years. Earth's interior remains active with a solid iron inner core , a liquid outer core that generates Earth's magnetic field , and a convecting mantle that drives plate tectonics. According to radiometric dating estimation and other evidence, Earth formed over 4.
Within the first billion years of Earth's history , life appeared in the oceans and began to affect Earth's atmosphere and surface, leading to the proliferation of anaerobic and, later , aerobic organisms. Some geological evidence indicates that life may have arisen as early as 4. Since then, the combination of Earth's distance from the Sun, physical properties and geological history have allowed life to evolve and thrive. In the history of life on Earth , biodiversity has gone through long periods of expansion, occasionally punctuated by mass extinctions.
Humans increasingly impact Earth's hydrology, atmospheric processes and other life. Earth's atmosphere consists mostly of nitrogen and oxygen. More solar energy is received by tropical regions than polar regions, and is redistributed by atmospheric and ocean circulation.
Greenhouse gases also play an important role in regulating the surface temperature. A region's climate is not only determined by latitude, but also by elevation, and by proximity to moderating oceans, among other factors. Extreme weather , such as tropical cyclones and heat waves , occurs in most areas and has a large impact on life. Earth's gravity interacts with other objects in space, especially the Sun and the Moon , which is Earth's only natural satellite. Earth orbits around the Sun in about Earth's axis of rotation is tilted with respect to its orbital plane, producing seasons on Earth.
The gravitational interaction between Earth and the Moon causes tides , stabilizes Earth's orientation on its axis, and gradually slows its rotation. Earth is the densest planet in the Solar System and the largest and most massive of the four rocky planets. Historically, earth has been written in lowercase.
From early Middle English , its definite sense as "the globe" was expressed as the earth. By Early Modern English , many nouns were capitalized, 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. 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? There are a number of adjectives for the planet Earth.
From Earth itself comes earthly. The oldest material found in the Solar System is dated to 4. 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.
A nebula contains gas, ice grains, and dust including primordial nuclides. According to nebular theory , planetesimals formed by accretion , with the primordial Earth being estimated as likely taking anywhere from 70— million years to form. Estimates of the age of the Moon range from 4. Earth's atmosphere and oceans were formed by volcanic activity and outgassing. As the molten outer layer of Earth cooled it formed the first solid crust , which is thought to have been mafic in composition.
The first continental crust , which was more felsic in composition, formed by the partial melting of this mafic crust. The presence of grains of the mineral zircon of Hadean age in Eoarchean sedimentary rocks suggests that at least some felsic crust existed as early as 4.
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. 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.
Chemical reactions led to the first self-replicating molecules about four billion years ago. A half billion years later, the last common ancestor of all current life arose.
The resultant molecular oxygen O 2 accumulated in the atmosphere and due to interaction with ultraviolet solar radiation, formed a protective ozone layer O 3 in the upper atmosphere. Aided by the absorption of harmful ultraviolet radiation by the ozone layer, life colonized Earth's surface.
This hypothesis has been termed " Snowball Earth ", and it is of particular interest because it preceded the Cambrian explosion , when multicellular life forms significantly increased in complexity. 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. Because carbon dioxide CO 2 has a long life time in the atmosphere, moderate human CO 2 emissions may postpone the next glacial inception by , years.
Over the next 1. The shape of Earth is nearly spherical. There is a small flattening at the poles and bulging around the equator due to Earth's rotation.
The point on the surface farthest from Earth's center of mass is the summit of the equatorial Chimborazo volcano in Ecuador 6, Local topography deviates from this idealized spheroid, although on a global scale these deviations are small compared to Earth's radius: the maximum deviation of only 0. More precisely, the geoid is the surface of gravitational equipotential at mean sea level. Earth's mass is approximately 5. It is composed mostly of iron Due to mass segregation , the core region is estimated to be primarily composed of iron Earth's interior, like that of the other terrestrial planets, is divided into layers by their chemical or physical rheological properties.
The outer layer is a chemically distinct silicate solid crust, which is underlain by a highly viscous solid mantle. The crust and the cold, rigid, top of the upper mantle are collectively known as the lithosphere, which is divided into independently moving tectonic plates. Beneath the lithosphere is the asthenosphere , a relatively low-viscosity layer on which the lithosphere rides.
Beneath the mantle, an extremely low viscosity liquid outer core lies above a solid inner core. Density increases with depth, as described in the table on the right. The major heat-producing isotopes within Earth are potassium , uranium , and thorium These plumes can produce hotspots and flood basalts.
The final major mode of heat loss is through conduction through the lithosphere, the majority of which occurs under the oceans because the crust there is much thinner than that of the continents.
Earth's mechanically rigid outer layer, the lithosphere, is divided into tectonic plates. 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. Along these plate boundaries, earthquakes , volcanic activity , mountain-building , and oceanic trench formation can occur.
As the tectonic plates migrate, oceanic crust is subducted under the leading edges of the plates at convergent boundaries. At the same time, the upwelling of mantle material at divergent boundaries creates mid-ocean ridges. The combination of these processes recycles the oceanic crust back into the mantle.
At the other extreme, the slowest-moving plate is the South American Plate, progressing at a typical rate of The remaining The continental crust consists of lower density material such as the igneous rocks granite and andesite.
Less common is basalt , a denser volcanic rock that is the primary constituent of the ocean floors. The most abundant silicate minerals on Earth's surface include quartz , feldspars , amphibole , mica , pyroxene and olivine. Erosion and tectonics , volcanic eruptions , flooding , weathering , glaciation , the growth of coral reefs , and meteorite impacts are among the processes that constantly reshape Earth's surface over geological time.
The pedosphere is the outermost layer of Earth's continental surface and is composed of soil and subject to soil formation processes.
The total arable land is The gravity of Earth is the acceleration that is imparted to objects due to the distribution of mass within Earth. Near Earth's surface, gravitational acceleration is approximately 9.
Local differences in topography, geology , and deeper tectonic structure cause local and broad, regional differences in Earth's gravitational field, known as gravity anomalies. The main part of Earth's magnetic field is generated in the core, the site of a dynamo process that converts the kinetic energy of thermally and compositionally driven convection into electrical and magnetic field energy.
The field extends outwards from the core, through the mantle, and up to Earth's surface, where it is, approximately, a dipole. The poles of the dipole are located close to Earth's geographic poles. At the equator of the magnetic field, the magnetic-field strength at the surface is 3. This causes secular variation of the main field and field reversals at irregular intervals averaging a few times every million years.
The most recent reversal occurred approximately , years ago. The extent of Earth's magnetic field in space defines the magnetosphere. Ions and electrons of the solar wind are deflected by the magnetosphere; solar wind pressure compresses the dayside of the magnetosphere, to about 10 Earth radii, and extends the nightside magnetosphere into a long tail. During magnetic storms and substorms , charged particles can be deflected from the outer magnetosphere and especially the magnetotail, directed along field lines into Earth's ionosphere, where atmospheric atoms can be excited and ionized, causing the aurora.
Earth's rotation period relative to the Sun—its mean solar day—is 86, seconds of mean solar time 86, For bodies near the celestial equator , this is equivalent to an apparent diameter of the Sun or the Moon every two minutes; from Earth's surface, the apparent sizes of the Sun and the Moon are approximately the same. The orbital speed of Earth averages about The Moon and Earth orbit a common barycenter every When combined with the Earth—Moon system's common orbit around the Sun, the period of the synodic month , from new moon to new moon, is Viewed from the celestial north pole , the motion of Earth, the Moon, and their axial rotations are all counterclockwise.
Viewed from a vantage point above the north poles of both the Sun and Earth, Earth orbits in a counterclockwise direction about the Sun. The orbital and axial planes are not precisely aligned: Earth's axis is tilted some
Interesting facts about the Moon
Planet Earth. That shiny blue marble that has fascinated humanity since they first began to walk across its surface. In addition to being our home and the place where life as we know it originated, it remains the only planet we know of where life thrives. And over the course of the past few centuries, we have learned much about Earth, which has only deepened our fascination with it. But how much does the average person really know about the planet Earth?
Our solar system is home to Earth and seven other planets. Each planet rotates on its own axis while revolving around the Sun. Every planet has unique characteristics and qualities that set it apart from the rest. The Sun keeps this complex arrangement in order. This unit reveals detailed facts about our Sun and the planets.
Mount Everest: 29, feet (8, meters) high. Other Interesting. Facts. • Third planet from the sun and the only world known to support an atmosphere with free.
Earth: Facts About Our Planet
Alien worlds may be all the rage, with their mystique and promise, but the orb we call home, planet Earth, has all the makings for a jaw-dropping blockbuster movie: from the drama of explosive volcanoes, past meteor crashes and catastrophic collisions between rocky plates to the seeming fantasy of the ocean's deep abysses swirling with odd life and tales of the coldest, hottest, deepest, highest and all-out extreme spots. Did you know Earth is not actually a sphere? That we are rocketing around the sun at 67, mph? That the majority of Earth's fresh water is locked up in Antarctica? We pawed through our archives to gather together just 50 of the most amazing and interesting facts about Earth.
Ever since the Big Bang, the Universe has been drifting and expanding. The birth and death of stars leave an aftermath of galaxies, planets, and even living organisms. Watch the Earth transform from a violent, molten rock to a supporter of life.
Earth, our home planet, is a world unlike any other. The third planet from the sun, Earth is the only place in the known universe confirmed to host life. With a radius of 3, miles, Earth is the fifth largest planet in our solar system, and it's the only one known for sure to have liquid water on its surface. Earth is also unique in terms of monikers. Earth orbits the sun once every
Insight Investment Astronomy Photographer of the Year photographers share their top facts about the Moon.
1. Plate Tectonics Keep the Planet Comfortable:
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