- Archean (Wikipedia)
The Archean Eon (IPA: /ɑːrˈkiːən/ ar-KEE-ən, also spelled Archaean or Archæan), in older sources sometimes called the Archaeozoic, is the second of the four geologic eons of Earth’s history, preceded by the Hadean Eon and followed by the Proterozoic. The Archean represents the time period from 4,031 to 2,500 Ma (millions of years ago). The Late Heavy Bombardment is hypothesized to overlap with the beginning of the Archean. The Huronian glaciation occurred at the end of the eon.
- Atlantic Ocean (Wikipedia)
The Atlantic Ocean is the second-largest of the world’s five oceans, with an area of about 106,460,000 km2 (41,100,000 sq mi). It covers approximately 20% of Earth’s surface and about 29% of its water surface area. It is known to separate the “Old World” of Africa, Europe, and Asia from the “New World” of the Americas in the European perception of the World.
- Bedrock (Wikipedia)
In geology, bedrock is solid rock that lies under loose material (regolith) within the crust of Earth or another terrestrial planet.
- Celestial sphere (Wikipedia)
In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer. If centered on the observer, half of the sphere would resemble a hemispherical screen over the observing location.
- Earth–Moon system (Wikipedia)
The Earth and the Moon form the Earth-Moon satellite system with a shared center of mass, or barycenter. This barycenter stays located at all times 1,700 km (1,100 mi) (about a quarter of Earth’s radius) beneath the Earth’s surface, making the Moon seemingly orbit the Earth.
- Flat Earth (Wikipedia)
Flat Earth is an archaic and scientifically disproven conception of the Earth’s shape as a plane or disk. Many ancient cultures subscribed to a flat-Earth cosmography.
- Geology (Wikipedia)
Geology (from Ancient Greek γῆ (gê) ’earth’, and λoγία (-logía) ‘study of, discourse’) is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with Earth system science and planetary science.
- Hadean (Wikipedia)
The Hadean (IPA: /heɪˈdiːən, ˈheɪdiən/ hay-DEE-ən, HAY-dee-ən) is the first and oldest of the four known geologic eons of Earth’s history. The Hadean eon started with the planet’s formation about 4.54 Bya, now defined as (4567.30 ± 0.16) Mya set by the age of the oldest solid material in the Solar System found in some meteorites about 4.567 billion years old. The proposed interplanetary collision that created the Moon occurred early in this eon, and the Late Heavy Bombardment is hypothesized to have occurred at the end of the eon. The Hadean ended 4.031 billion years ago, and was succeeded by the Archean eon.
- Lithosphere (Wikipedia)
A lithosphere (from Ancient Greek λίθος (líthos) ‘rocky’, and σφαίρα (sphaíra) ‘sphere’) is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time scales of up to thousands of years or more. The crust and upper mantle are distinguished on the basis of chemistry and mineralogy.
- Mesoproterozoic (Wikipedia)
The Mesoproterozoic Era is a geologic era that occurred from 1,600 to 1,000 million years ago. The Mesoproterozoic was the first era of Earth’s history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic), but little is known about them. The continental masses of the Mesoproterozoic were more or less the same ones that exist today, although their arrangement on the Earth’s surface was different.
- Morton Gneiss (Wikipedia)
Morton gneiss, also known as rainbow gneiss, is an [Archean](/en.wikipedia.org/wiki/Archean/-age gneiss found in the Minnesota River Valley of southwestern Minnesota, United States. It is one of the oldest stones on Earth, at about 3.5 billion years old. Along with the nearby Montevideo Gneiss, it is the oldest intact continental crust rock in the United States. Its type locality is in Morton, Minnesota.
- North American Plate (Wikipedia)
The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of 76 million km2 (29 million sq mi), it is the Earth’s second largest tectonic plate, behind the Pacific Plate (which borders the plate to the west).
- Northern celestial hemisphere (Wikipedia)
The northern celestial hemisphere, also called the Northern Sky, is the northern half of the celestial sphere; that is, it lies north of the celestial equator. This arbitrary sphere appears to rotate westward around a polar axis due to Earth’s rotation.
- Pacific Ocean (Wikipedia)
The Pacific Ocean is the largest and deepest of Earth’s five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continents of Asia and Oceania in the west and the Americas in the east.
- Paleoproterozoic (Wikipedia)
The Paleoproterozoic Era (also spelled Palaeoproterozoic) is the first of the three sub-divisions (eras) of the Proterozoic eon, and also the longest era of the Earth’s geological history, spanning from 2,500 to 1,600 million years ago (2.5–1.6 Ga). It is further subdivided into four geologic periods, namely the Siderian, Rhyacian, Orosirian and Statherian.
- Pangaea (Wikipedia)
Pangaea or Pangea (/pænˈdʒiː.ə/) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million years ago, and began to break apart about 200 million years ago, at the end of the Triassic and beginning of the Jurassic. In contrast to the present Earth and its distribution of continental mass, Pangaea was centred on the equator and surrounded by the superocean Panthalassa and the Paleo-Tethys and subsequent Tethys Oceans. Pangaea is the most recent supercontinent to have existed and the first to be reconstructed by geologists.
- Panthalassa (Wikipedia)
Panthalassa, also known as the Panthalassic Ocean or Panthalassan Ocean (from Greek πᾶν “all” and θάλασσα “sea”), was the superocean that surrounded the supercontinent Pangaea, the latest in a series of supercontinents in the history of Earth. During the Paleozoic–Mesozoic transition c. 250 Ma it occupied almost 70% of Earth’s surface. Its ocean floor has completely disappeared because of the continuous subduction along the continental margins on its circumference. Panthalassa is also referred to as the Paleo-Pacific (“old Pacific”) or Proto-Pacific because the Pacific Ocean is a direct continuation of Panthalassa.
- Phanerozoic (Wikipedia)
The Phanerozoic is the current and the latest of the four geologic eons in the Earth’s geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and plant life has proliferated, diversified and colonized various niches on the Earth’s surface, beginning with the Cambrian period when animals first developed hard shells that can be clearly preserved in the fossil record. The time before the Phanerozoic, collectively called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons.
- Solar eclipse (Wikipedia)
A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of the Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season in its new moon phase, when the Moon’s orbital plane is closest to the plane of the Earth’s orbit. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses, only part of the Sun is obscured. Unlike a lunar eclipse, which may be viewed from anywhere on the night side of Earth, a solar eclipse can only be viewed from a relatively small area of the world. As such, although total solar eclipses occur somewhere on Earth every 18 months on average, they recur at any given place only once every 360 to 410 years.
- Southern celestial hemisphere (Wikipedia)
The southern celestial hemisphere, also called the Southern Sky, is the southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, appears to rotate westward around a polar axis due to Earth’s rotation.
- Stranger in a Strange Land (Wikipedia)
Stranger in a Strange Land is a 1961 science fiction novel by American author Robert A. Heinlein. It tells the story of Valentine Michael Smith, a human who comes to Earth in early adulthood after being born on the planet Mars and raised by Martians, and explores his interaction with an eventual transformation of Terran culture.
- Earth is the third planet from the Sun and the only place known in the universe where life has originated and found habitability. Earth is the only planet known to sustain liquid surface water, with ocean water extending over 70.8% of the planet, making it an ocean world. Most of all other water is retained in Earth’s polar regions, with large sheets of ice covering ocean and land, dwarfing Earth’s groundwater, lakes, rivers and atmospheric water. The other 29.2% of the Earth’s surface is land, consisting of continents and islands, and is widely covered by vegetation. Below the planet’s surface lies the crust, consisting of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Inside the Earth’s crust is a liquid outer core that generates the magnetosphere, deflecting most of the destructive solar winds and cosmic radiation.