244 relations: Abiogenesis, Acceleration, Adaptive optics, Alan Stern, American Dialect Society, Ancient Greek phonology, Angular diameter, Angular momentum, Angular resolution, Antarctic ice sheet, Apparent magnitude, Apparent retrograde motion, Applied Physics Laboratory, Apsidal precession, Apsis, Argument of periapsis, Asteroid, Asteroid belt, Astrological symbols, Astronomical symbols, Astronomical unit, Atmosphere, Atmosphere of Pluto, Bar (unit), Barycenter, Ben Sharpsteen, Binary system, Blink comparator, Bodleian Library, Brady Haran, Brown University, California Institute of Technology, California State Assembly, Callisto (moon), Carbon monoxide, Côte d'Azur Observatory, Ceres (dwarf planet), Chaos theory, Charon (moon), Chemical element, Circumbinary planet, Classical mechanics, Classical mythology, Clearing the neighbourhood, Clyde Tombaugh, Comet, Convection cell, Cronus, Cryovolcano, Cthulhu Macula, ..., Dale Cruikshank, David Morrison (astrophysicist), Degree (angle), Delta Geminorum, Digital compositing, Digital imaging, Double planet, Dune, Dwarf planet, Dysnomia (moon), E. Myles Standish, Earth, Earth mass, Earth radius, Ecliptic, Ellipse, Epoch (astronomy), Equator, Eris (dwarf planet), Ernest William Brown, Europa (moon), Falconer Madan, Flagstaff, Arizona, G-force, Ganymede (moon), Gemini Observatory, Geography of Pluto, Geometric albedo, Gerard Kuiper, Giant planet, Glaciology, Glenn T. Seaborg, Gravitational constant, Gravity assist, Greenhouse gas, Harvard College Observatory, Hōei Nojiri, Herbert Hall Turner, Hindi, Hindu, How I Killed Pluto and Why It Had It Coming, Hubble Space Telescope, Hydra (moon), Hydrostatic equilibrium, Iapetus (moon), IAU definition of planet, Icarus (journal), Illinois Senate, International Astronomical Union, Inversion (meteorology), Io (moon), James W. Christy, JPL Horizons On-Line Ephemeris System, Julian year (astronomy), Jupiter, Jupiter trojan, Kelvin, Kepler's laws of planetary motion, Kerberos (moon), Kozai mechanism, Kuiper belt, Languages of India, Late Heavy Bombardment, Libration, List of minor planets, Lowell Observatory, Lyapunov time, Macromolecule, Mantle (geology), Marc William Buie, Mars, Mass wasting, Māori language, Methane, Michael E. Brown, Mickey Mouse, Minerva, Minor planet designation, Monogram, Moon, Moons of Pluto, NASA, National Geographic, Natural satellite, Navajo language, Neptune, Neptunium, New Horizons, New Mexico House of Representatives, New Scientist, Nice, Nicholas Mayall, Nitrogen, Nix (moon), Ocean, Orbital eccentricity, Orbital inclination, Orbital resonance, Organic compound, Oxford, Pascal (unit), Percival Lowell, Perihelion and aphelion, Perturbation (astronomy), Phonology, Plane (geometry), Planet, Planetary core, Planetary flyby, Planetary migration, Planetesimal, Planets beyond Neptune, Plate tectonics, Plutino, Pluto (Disney), Pluto (mythology), Pluto in fiction, Plutoid, Plutonium, Polar wander, Polynesian languages, Pound sterling, Precovery, Protoplanetary disk, Quasi-satellite, Remote sensing, Retrograde and prograde motion, Robert Sutton Harrington, Rose Center for Earth and Space, Rotation period, Russia, Saturn, Scattered disc, Scientific American, Semi-major and semi-minor axes, Seth Barnes Nicholson, Sino-Vietnamese vocabulary, Solar System, Solar time, Solar wind, Solid nitrogen, Solstice, Somali language, Space exploration, Space Telescope Science Institute, Space.com, Spectroscopy, Sputnik Planitia, Styx (moon), Sublimation (phase transition), Sun, Surface area, Surface gravity, Terrestrial planet, The New York Times, The Planetary Society, The Walt Disney Company, Tholin, Thomas Jefferson Jackson See, Tidal locking, Time reversibility, Titan (moon), Tombaugh Regio, Trans-Neptunian object, Triton (moon), Unicode, United States dollar, University of Arizona, University of Arizona Press, University of Hawaii, University of Nottingham, University of Oxford, Uranium, Uranus, Urbain Le Verrier, USA Today, Vapor pressure, Venetia Burney, Vesto Slipher, Voyager 2, Walt Disney, Whiro, Wiley-VCH, William Henry Pickering, Yama, Yama (Buddhism), Yerkes Observatory, Zeus, 1163 Saga, 15810 Arawn, 2 Pallas, 3 Juno, 4 Vesta, 617 Patroclus. Expand index (194 more) » « Shrink index
Abiogenesis, or informally the origin of life,Compare: Also occasionally called biopoiesis.
In physics, acceleration is the rate of change of velocity of an object with respect to time.
Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion.
Sol Alan Stern (born November 22, 1957) is an American engineer and planetary scientist.
The American Dialect Society (ADS), founded in 1889, is a learned society "dedicated to the study of the English language in North America, and of other languages, or dialects of other languages, influencing it or influenced by it." The Society publishes the academic journal, American Speech.
Ancient Greek phonology is the description of the reconstructed phonology or pronunciation of Ancient Greek.
The angular diameter, angular size, apparent diameter, or apparent size is an angular measurement describing how large a sphere or circle appears from a given point of view.
In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of linear momentum.
Angular resolution or spatial resolution describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution.
The Antarctic ice sheet is one of the two polar ice caps of the Earth.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
Apparent retrograde motion is the apparent motion of a planet in a direction opposite to that of other bodies within its system, as observed from a particular vantage point.
The Johns Hopkins University Applied Physics Laboratory, commonly known as simply the Applied Physics Laboratory, or APL, located in Howard County, Maryland, near Laurel and Columbia, is a not-for-profit, university-affiliated research center (or UARC) employing 6,000 people.
In celestial mechanics, apsidal precession or orbital precession is the precession (rotation) of the orbit of a celestial body.
An apsis (ἁψίς; plural apsides, Greek: ἁψῖδες) is an extreme point in the orbit of an object.
The argument of periapsis (also called argument of perifocus or argument of pericenter), symbolized as ω, is one of the orbital elements of an orbiting body.
Asteroids are minor planets, especially those of the inner Solar System.
The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter.
Symbols used in astrology overlap with those used in astronomy because of the historical overlap between the two subjects.
Astronomical symbols are symbols used to represent astronomical objects, theoretical constructs and observational events in astronomy.
The astronomical unit (symbol: au, ua, or AU) is a unit of length, roughly the distance from Earth to the Sun.
An atmosphere is a layer or a set of layers of gases surrounding a planet or other material body, that is held in place by the gravity of that body.
The atmosphere of Pluto is the tenuous layer of gases surrounding Pluto.
The bar is a metric unit of pressure, but is not approved as part of the International System of Units (SI).
The barycenter (or barycentre; from the Ancient Greek βαρύς heavy + κέντρον centre) is the center of mass of two or more bodies that are orbiting each other, which is the point around which they both orbit.
Benjamin Sharpsteen (November 4, 1895 – December 20, 1980) was an American film director and producer for Disney.
A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter (also see animated examples).
A blink comparator was a viewing apparatus used by astronomers to find differences between two photographs of the night sky.
The Bodleian Library is the main research library of the University of Oxford, and is one of the oldest libraries in Europe.
Brady John Haran (born 18 June 1976) is an Australian-born British independent filmmaker and video journalist who is known for his educational videos and documentary films produced for BBC News and his YouTube channels, the most notable being Periodic Videos and Numberphile.
Brown University is a private Ivy League research university in Providence, Rhode Island, United States.
The California Institute of Technology (abbreviated Caltech)The university itself only spells its short form as "Caltech"; other spellings such as.
The California State Assembly is the lower house of the California State Legislature.
Callisto (Jupiter IV) is the second-largest moon of Jupiter, after Ganymede.
Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is slightly less dense than air.
The Côte d'Azur Observatory (Observatoire de la Côte d'Azur, OCA) originated in 1988 with the merger of two observatories.
Ceres (minor-planet designation: 1 Ceres) is the largest object in the asteroid belt that lies between the orbits of Mars and Jupiter, slightly closer to Mars' orbit.
Chaos theory is a branch of mathematics focusing on the behavior of dynamical systems that are highly sensitive to initial conditions.
Charon, also known as (134340) Pluto I, is the largest of the five known natural satellites of the dwarf planet Pluto.
A chemical element is a species of atoms having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).
Christmas is an annual festival commemorating the birth of Jesus Christ,Martindale, Cyril Charles.
The Christmas season, also called the festive season, or the holiday season (mainly in the U.S. and Canada; often simply called the holidays),, is an annually recurring period recognized in many Western and Western-influenced countries that is generally considered to run from late November to early January.
Christmas Eve is the evening or entire day before Christmas Day, the festival commemorating the birth of Jesus.
Christmas traditions vary from country to country.
A circumbinary planet is a planet that orbits two stars instead of one.
Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars and galaxies.
Classical Greco-Roman mythology, Greek and Roman mythology or Greco-Roman mythology is both the body of and the study of myths from the ancient Greeks and Romans as they are used or transformed by cultural reception.
"Clearing the neighbourhood around its orbit" is a criterion for a celestial body to be considered a planet in the Solar System.
Clyde William Tombaugh (February 4, 1906January 17, 1997) was an American astronomer.
A comet is an icy small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing.
In the field of fluid dynamics, a convection cell is the phenomenon that occurs when density differences exist within a body of liquid or gas.
In Greek mythology, Cronus, Cronos, or Kronos (or from Κρόνος, Krónos), was the leader and youngest of the first generation of Titans, the divine descendants of Uranus, the sky, and Gaia, the earth.
A cryovolcano (sometimes informally called an ice volcano) is a type of volcano that erupts volatiles such as water, ammonia or methane, instead of molten rock.
Cthulhu Macula (formerly Cthulhu Regio) is a prominent surface feature of the dwarf planet Pluto, that is reminiscent of a whale in shape.
David Morrison (born 26 June 1940) is an American astronomer, a senior scientist at the Solar System Exploration Research Virtual Institute, at NASA Ames Research Center in Mountain View, California.
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle, defined so that a full rotation is 360 degrees.
Delta Geminorum (δ Geminorum, abbreviated Delta Gem, δ Gem), also named Wasat, is a triple star system in the constellation of Gemini.
Digital compositing is the process of digitally assembling multiple images to make a final image, typically for print, motion pictures or screen display.
Digital imaging or digital image acquisition is the creation of a digitally encoded representation of the visual characteristics of an object, such as a physical scene or the interior structure of an object.
In astronomy, a double planet (also binary planet) is a binary system where both objects are of planetary mass.
In physical geography, a dune is a hill of loose sand built by aeolian processes (wind) or the flow of water.
A dwarf planet is a planetary-mass object that is neither a planet nor a natural satellite.
Dysnomia (Greek: Δυσνομία)—officially (136199) Eris I Dysnomia—is the only known moon of the dwarf planet Eris (the most massive known dwarf planet in the Solar System).
Erland Myles Standish, Jr. (born March 5, 1939) is a mathematical astronomer and a former professor at Yale University.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
Earth mass (where ⊕ is the standard astronomical symbol for planet Earth) is the unit of mass equal to that of Earth.
Earth radius is the approximate distance from Earth's center to its surface, about.
The ecliptic is the circular path on the celestial sphere that the Sun follows over the course of a year; it is the basis of the ecliptic coordinate system.
In mathematics, an ellipse is a curve in a plane surrounding two focal points such that the sum of the distances to the two focal points is constant for every point on the curve.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
An equator of a rotating spheroid (such as a planet) is its zeroth circle of latitude (parallel).
Eris (minor-planet designation 136199 Eris) is the most massive and second-largest (by volume) dwarf planet in the known Solar System.
Ernest William Brown FRS (29 November 1866 – 22 July 1938) was an English mathematician and astronomer, who spent the majority of his career working in the United States and became a naturalised American citizen in 1923.
Europa or as Ευρώπη (Jupiter II) is the smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet.
Falconer Madan (15 April 1851 — 22 May 1935) was Librarian of the Bodleian Library of Oxford University.
Flagstaff is a city in and the county seat of Coconino County in northern Arizona, in the southwestern United States.
The gravitational force, or more commonly, g-force, is a measurement of the type of acceleration that causes a perception of weight.
Ganymede (Jupiter III) is the largest and most massive moon of Jupiter and in the Solar System.
The Gemini Observatory is an astronomical observatory consisting of two 8.19-metre (26.9 ft) telescopes, Gemini North and Gemini South, which are located at two separate sites in Hawaii and Chile, respectively.
The geography of Pluto entails the delineation and characterization of regions on Pluto.
In astronomy, the geometric albedo of a celestial body is the ratio of its actual brightness as seen from the light source (i.e. at zero phase angle) to that of an idealized flat, fully reflecting, diffusively scattering (Lambertian) disk with the same cross-section.
Gerard Peter Kuiper (born Gerrit Pieter Kuiper; December 7, 1905 – December 23, 1973) was a Dutch–American astronomer, planetary scientist, selenographer, author and professor.
A giant planet is any massive planet.
Glaciology (from Latin: glacies, "frost, ice", and Ancient Greek: λόγος, logos, "subject matter"; literally "study of ice") is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice.
Glenn Theodore Seaborg (April 19, 1912February 25, 1999) was an American chemist whose involvement in the synthesis, discovery and investigation of ten transuranium elements earned him a share of the 1951 Nobel Prize in Chemistry.
The gravitational constant (also known as the "universal gravitational constant", the "Newtonian constant of gravitation", or the "Cavendish gravitational constant"), denoted by the letter, is an empirical physical constant involved in the calculation of gravitational effects in Sir Isaac Newton's law of universal gravitation and in Albert Einstein's general theory of relativity.
In orbital mechanics and aerospace engineering, a gravitational slingshot, gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expense.
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiant energy within the thermal infrared range.
The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy.
was a Japanese essayist and astronomer.
Herbert Hall Turner FRS (13 August 1861, Leeds – 20 August 1930, Stockholm) was a British astronomer and seismologist.
Hindi (Devanagari: हिन्दी, IAST: Hindī), or Modern Standard Hindi (Devanagari: मानक हिन्दी, IAST: Mānak Hindī) is a standardised and Sanskritised register of the Hindustani language.
Hindu refers to any person who regards themselves as culturally, ethnically, or religiously adhering to aspects of Hinduism.
How I Killed Pluto and Why It Had It Coming is the 2010 memoir by Mike Brown, the American astronomer most responsible for the reclassification of the former planet Pluto from planet to dwarf planet.
The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.
Hydra is the outermost known moon of Pluto.
In fluid mechanics, a fluid is said to be in hydrostatic equilibrium or hydrostatic balance when it is at rest, or when the flow velocity at each point is constant over time.
Iapetus (Ιαπετός), or occasionally Japetus, is the third-largest natural satellite of Saturn, eleventh-largest in the Solar System, and the largest body in the Solar System known not to be in hydrostatic equilibrium.
The International Astronomical Union (IAU) defined in August 2006 that, in the Solar System, a planet is a celestial body which.
Icarus is a scientific journal dedicated to the field of planetary science.
The Illinois Senate is the upper chamber of the Illinois General Assembly, the legislative branch of the government of the state of Illinois in the United States.
The International Astronomical Union (IAU; Union astronomique internationale, UAI) is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy.
In meteorology, an inversion is a deviation from the normal change of an atmospheric property with altitude.
Io (Jupiter I) is the innermost of the four Galilean moons of the planet Jupiter.
James Walter "Jim" Christy (born September 15, 1938) is an American astronomer.
JPL Horizons On-Line Ephemeris System provides easy access to key Solar System data and flexible production of highly accurate ephemerides for Solar System objects.
In astronomy, a Julian year (symbol: a) is a unit of measurement of time defined as exactly 365.25 days of SI seconds each.
Jupiter is the fifth planet from the Sun and the largest in the Solar System.
The Jupiter trojans, commonly called Trojan asteroids or just Trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun.
The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
In astronomy, Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun.
Kerberos is a small natural satellite of Pluto, about in its longest dimension.
In celestial mechanics, the Kozai mechanism or Lidov–Kozai mechanism or Kozai–Lidov mechanism, also known as the Kozai, Lidov–Kozai or Kozai–Lidov effect, oscillations, cycles or resonance, is a dynamical phenomenon affecting the orbit of a binary system perturbed by a distant third body under certain conditions, causing the orbit's argument of pericenter to oscillate about a constant value, which in turn leads to a periodic exchange between its eccentricity and inclination.
The Kuiper belt, occasionally called the Edgeworth–Kuiper belt, is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun.
Languages spoken in India belong to several language families, the major ones being the Indo-Aryan languages spoken by 76.5% of Indians and the Dravidian languages spoken by 20.5% of Indians.
The Late Heavy Bombardment (abbreviated LHB and also known as the lunar cataclysm) is an event thought to have occurred approximately 4.1 to 3.8 billion years (Ga) ago, at a time corresponding to the Neohadean and Eoarchean eras on Earth.
In astronomy, libration is a perceived oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of trojan asteroids relative to planets.
This is a list of numbered minor planets in numerical order.
Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States.
In mathematics, the Lyapunov time is the characteristic timescale on which a dynamical system is chaotic.
A macromolecule is a very large molecule, such as protein, commonly created by the polymerization of smaller subunits (monomers).
The mantle is a layer inside a terrestrial planet and some other rocky planetary bodies.
Marc William Buie (born 1958) is an American astronomer and prolific discoverer of minor planets, who used to be at Lowell Observatory in Flagstaff, Arizona, and also the Sentinel Space Telescope Mission Scientist for the B612 Foundation, which is dedicated to protecting Earth from asteroid impact events.
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury.
Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, sand, regolith, and rock move downslope typically as a solid, continuous or discontinuous mass, largely under the force of gravity, but frequently with characteristics of a flow as in debris flows and mudflows.
Māori, also known as te reo ("the language"), is an Eastern Polynesian language spoken by the Māori people, the indigenous population of New Zealand.
Methane is a chemical compound with the chemical formula (one atom of carbon and four atoms of hydrogen).
Michael E. Brown (born June 5, 1965) is an American astronomer, who has been professor of planetary astronomy at the California Institute of Technology (Caltech) since 2003.
Mickey Mouse is a funny animal cartoon character and the mascot of The Walt Disney Company.
Minerva (Etruscan: Menrva) was the Roman goddess of wisdom and strategic warfare, although it is noted that the Romans did not stress her relation to battle and warfare as the Greeks would come to, and the sponsor of arts, trade, and strategy.
A formal minor planet designation is, in its final form, a number–name combination given to a minor planet (asteroid, centaur, trans-Neptunian object and dwarf planet but not comet).
A monogram is a motif made by overlapping or combining two or more letters or other graphemes to form one symbol.
The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite.
The dwarf planet Pluto has five moons down to a detection limit of about 1 km in diameter.
The National Aeronautics and Space Administration (NASA) is an independent agency of the executive branch of the United States federal government responsible for the civilian space program, as well as aeronautics and aerospace research.
National Geographic (formerly the National Geographic Magazine and branded also as NAT GEO or) is the official magazine of the National Geographic Society.
A natural satellite or moon is, in the most common usage, an astronomical body that orbits a planet or minor planet (or sometimes another small Solar System body).
Navajo or Navaho (Navajo: Diné bizaad or Naabeehó bizaad) is a Southern Athabaskan language of the Na-Dené family, by which it is related to languages spoken across the western areas of North America.
Neptune is the eighth and farthest known planet from the Sun in the Solar System.
Neptunium is a chemical element with symbol Np and atomic number 93.
New Horizons is an interplanetary space probe that was launched as a part of NASA's New Frontiers program.
The New Mexico House of Representatives (Cámara de representantes de Nuevo México)is the lower house of the New Mexico State Legislature.
New Scientist, first published on 22 November 1956, is a weekly, English-language magazine that covers all aspects of science and technology.
New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one.
New Year's Day, also called simply New Year's or New Year, is observed on January 1, the first day of the year on the modern Gregorian calendar as well as the Julian calendar.
In the Gregorian calendar, New Year's Eve (also known as Old Year's Day or Saint Sylvester's Day in many countries), the last day of the year, is on 31 December which is the seventh day of Christmastide.
Nice (Niçard Niça, classical norm, or Nissa, nonstandard,; Nizza; Νίκαια; Nicaea) is the fifth most populous city in France and the capital of the Alpes-Maritimes département.
Nicholas Ulrich Mayall (May 9, 1906 – January 5, 1993) was an American observational astronomer.
Nitrogen is a chemical element with symbol N and atomic number 7.
Nix is a natural satellite of Pluto.
An ocean (the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere.
The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle.
Orbital inclination measures the tilt of an object's orbit around a celestial body.
In celestial mechanics, an orbital resonance occurs when orbiting bodies exert a regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers.
In chemistry, an organic compound is generally any chemical compound that contains carbon.
Oxford is a city in the South East region of England and the county town of Oxfordshire.
The pascal (symbol: Pa) is the SI derived unit of pressure used to quantify internal pressure, stress, Young's modulus and ultimate tensile strength.
Percival Lawrence Lowell (March 13, 1855 – November 12, 1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars.
The perihelion of any orbit of a celestial body about the Sun is the point where the body comes nearest to the Sun.
In astronomy, perturbation is the complex motion of a massive body subject to forces other than the gravitational attraction of a single other massive body.
Phonology is a branch of linguistics concerned with the systematic organization of sounds in languages.
In mathematics, a plane is a flat, two-dimensional surface that extends infinitely far.
A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
The planetary core consists of the innermost layer(s) of a planet; which may be composed of solid and liquid layers.
A planetary flyby is the act of sending a space probe past a planet or a dwarf planet close enough to record scientific data.
Planetary migration occurs when a planet or other stellar satellite interacts with a disk of gas or planetesimals, resulting in the alteration of the satellite's orbital parameters, especially its semi-major axis.
Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks.
Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit.
Plate tectonics (from the Late Latin tectonicus, from the τεκτονικός "pertaining to building") is a scientific theory describing the large-scale motion of seven large plates and the movements of a larger number of smaller plates of the Earth's lithosphere, since tectonic processes began on Earth between 3 and 3.5 billion years ago.
In astronomy, the plutinos are a dynamical group of trans-Neptunian objects in the outermost region of the Solar System that orbit in 2:3 mean-motion resonance with Neptune.
Pluto, also called Pluto the Pup, is a cartoon dog created in 1930 at Walt Disney Productions.
Pluto (Latin: Plūtō; Πλούτων) was the ruler of the underworld in classical mythology.
Pluto has been featured in many instances of science fiction and popular culture.
A plutoid or ice dwarf is a trans-Neptunian dwarf planet, i.e. a body orbiting beyond Neptune that is massive enough to be rounded in shape.
Plutonium is a radioactive chemical element with symbol Pu and atomic number 94.
Polar wander is the motion of a pole in relation to a fixed reference frame.
The Polynesian languages are a language family spoken in geographical Polynesia and on a patchwork of outliers from south central Micronesia to small islands off the northeast of the larger islands of the southeast Solomon Islands and sprinkled through Vanuatu.
The pound sterling (symbol: £; ISO code: GBP), commonly known as the pound and less commonly referred to as Sterling, is the official currency of the United Kingdom, Jersey, Guernsey, the Isle of Man, South Georgia and the South Sandwich Islands, the British Antarctic Territory, and Tristan da Cunha.
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of an object in old archived images or photographic plates for the purpose of calculating a more accurate orbit.
A protoplanetary disk is a rotating circumstellar disk of dense gas and dust surrounding a young newly formed star, a T Tauri star, or Herbig Ae/Be star.
A quasi-satellite is an object in a specific type of co-orbital configuration (1:1 orbital resonance) with a planet where the object stays close to that planet over many orbital periods.
Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on-site observation.
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is the central object (right figure).
Robert Sutton Harrington (October 21, 1942 – January 23, 1993) was an American astronomer who worked at the United States Naval Observatory (USNO).
The Rose Center for Earth and Space is a part of the American Museum of Natural History in New York City.
In astronomy, the rotation period of a celestial object is the time that it takes to complete one revolution around its axis of rotation relative to the background stars.
Russia (rɐˈsʲijə), officially the Russian Federation (p), is a country in Eurasia. At, Russia is the largest country in the world by area, covering more than one-eighth of the Earth's inhabited land area, and the ninth most populous, with over 144 million people as of December 2017, excluding Crimea. About 77% of the population live in the western, European part of the country. Russia's capital Moscow is one of the largest cities in the world; other major cities include Saint Petersburg, Novosibirsk, Yekaterinburg and Nizhny Novgorod. Extending across the entirety of Northern Asia and much of Eastern Europe, Russia spans eleven time zones and incorporates a wide range of environments and landforms. From northwest to southeast, Russia shares land borders with Norway, Finland, Estonia, Latvia, Lithuania and Poland (both with Kaliningrad Oblast), Belarus, Ukraine, Georgia, Azerbaijan, Kazakhstan, China, Mongolia and North Korea. It shares maritime borders with Japan by the Sea of Okhotsk and the U.S. state of Alaska across the Bering Strait. The East Slavs emerged as a recognizable group in Europe between the 3rd and 8th centuries AD. Founded and ruled by a Varangian warrior elite and their descendants, the medieval state of Rus arose in the 9th century. In 988 it adopted Orthodox Christianity from the Byzantine Empire, beginning the synthesis of Byzantine and Slavic cultures that defined Russian culture for the next millennium. Rus' ultimately disintegrated into a number of smaller states; most of the Rus' lands were overrun by the Mongol invasion and became tributaries of the nomadic Golden Horde in the 13th century. The Grand Duchy of Moscow gradually reunified the surrounding Russian principalities, achieved independence from the Golden Horde. By the 18th century, the nation had greatly expanded through conquest, annexation, and exploration to become the Russian Empire, which was the third largest empire in history, stretching from Poland on the west to Alaska on the east. Following the Russian Revolution, the Russian Soviet Federative Socialist Republic became the largest and leading constituent of the Union of Soviet Socialist Republics, the world's first constitutionally socialist state. The Soviet Union played a decisive role in the Allied victory in World War II, and emerged as a recognized superpower and rival to the United States during the Cold War. The Soviet era saw some of the most significant technological achievements of the 20th century, including the world's first human-made satellite and the launching of the first humans in space. By the end of 1990, the Soviet Union had the world's second largest economy, largest standing military in the world and the largest stockpile of weapons of mass destruction. Following the dissolution of the Soviet Union in 1991, twelve independent republics emerged from the USSR: Russia, Ukraine, Belarus, Kazakhstan, Uzbekistan, Armenia, Azerbaijan, Georgia, Kyrgyzstan, Moldova, Tajikistan, Turkmenistan and the Baltic states regained independence: Estonia, Latvia, Lithuania; the Russian SFSR reconstituted itself as the Russian Federation and is recognized as the continuing legal personality and a successor of the Soviet Union. It is governed as a federal semi-presidential republic. The Russian economy ranks as the twelfth largest by nominal GDP and sixth largest by purchasing power parity in 2015. Russia's extensive mineral and energy resources are the largest such reserves in the world, making it one of the leading producers of oil and natural gas globally. The country is one of the five recognized nuclear weapons states and possesses the largest stockpile of weapons of mass destruction. Russia is a great power as well as a regional power and has been characterised as a potential superpower. It is a permanent member of the United Nations Security Council and an active global partner of ASEAN, as well as a member of the G20, the Shanghai Cooperation Organisation (SCO), the Council of Europe, the Asia-Pacific Economic Cooperation (APEC), the Organization for Security and Co-operation in Europe (OSCE), and the World Trade Organization (WTO), as well as being the leading member of the Commonwealth of Independent States (CIS), the Collective Security Treaty Organization (CSTO) and one of the five members of the Eurasian Economic Union (EEU), along with Armenia, Belarus, Kazakhstan and Kyrgyzstan.
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.
The scattered disc (or scattered disk) is a distant circumstellar disc in the Solar System that is sparsely populated by icy small solar system bodies, and are a subset of the broader family of trans-Neptunian objects.
Scientific American (informally abbreviated SciAm) is an American popular science magazine.
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the widest points of the perimeter.
Seth Barnes Nicholson (November 12, 1891 – July 2, 1963) was an American astronomer.
Sino-Vietnamese vocabulary (Từ Hán Việt, Chữ Nôm:, literally "Sino-Vietnamese words") are words and morphemes of the Vietnamese language borrowed from Chinese.
The Solar SystemCapitalization of the name varies.
Solar time is a calculation of the passage of time based on the position of the Sun in the sky.
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona.
Solid nitrogen is the solid form of the element nitrogen.
A solstice is an event occurring when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere.
Somali Retrieved on 21 September 2013 (Af-Soomaali) is an Afroasiatic language belonging to the Cushitic branch.
Space exploration is the discovery and exploration of celestial structures in outer space by means of evolving and growing space technology.
The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST; in orbit since 1990) and for the James Webb Space Telescope (JWST; scheduled to be launched in March 2021).
Space.com is a space and astronomy news website.
Spectroscopy is the study of the interaction between matter and electromagnetic radiation.
Sputnik Planitia,Also, originally Sputnik Planum, is a high-albedo ice-covered basin on Pluto, about in size, named after Earth's first artificial satellite.
Styx is a small natural satellite of Pluto whose discovery was announced on 11 July 2012.
Sublimation is the transition of a substance directly from the solid to the gas phase, without passing through the intermediate liquid phase.
The Sun is the star at the center of the Solar System.
The surface area of a solid object is a measure of the total area that the surface of the object occupies.
The surface gravity, g, of an astronomical or other object is the gravitational acceleration experienced at its surface.
A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals.
The New York Times (sometimes abbreviated as The NYT or The Times) is an American newspaper based in New York City with worldwide influence and readership.
The Planetary Society is an American internationally active, non-governmental, nonprofit foundation.
The Walt Disney Company, commonly known as Disney, is an American diversified multinational mass media and entertainment conglomerate, headquartered at the Walt Disney Studios in Burbank, California.
Tholins (after the Greek θολός (tholós) "hazy" or "muddy"; from the ancient Greek word meaning "sepia ink") are a wide variety of organic compounds formed by solar ultraviolet irradiation or cosmic rays from simple carbon-containing compounds such as carbon dioxide, methane or ethane, often in combination with nitrogen.
Thomas Jefferson Jackson (T. J. J.) See (February 19, 1866 – July 4, 1962) was an American astronomer whose promulgated theories in astronomy and physics were eventually disproven.
Tidal locking (also called gravitational locking or captured rotation) occurs when the long-term interaction between a pair of co-orbiting astronomical bodies drives the rotation rate of at least one of them into the state where there is no more net transfer of angular momentum between this body (e.g. a planet) and its orbit around the second body (e.g. a star); this condition of "no net transfer" must be satisfied over the course of one orbit around the second body.
A mathematical or physical process is time-reversible if the dynamics of the process remain well-defined when the sequence of time-states is reversed.
Titan is the largest moon of Saturn.
Tombaugh Regio,Also nicknamed The Heart after its shape, is the largest bright surface feature of the dwarf planet Pluto.
A trans-Neptunian object (TNO, also written transneptunian object) is any minor planet in the Solar System that orbits the Sun at a greater average distance (semi-major axis) than Neptune, 30 astronomical units (AU).
Triton is the largest natural satellite of the planet Neptune, and the first Neptunian moon to be discovered.
Unicode is a computing industry standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems.
The United States dollar (sign: $; code: USD; also abbreviated US$ and referred to as the dollar, U.S. dollar, or American dollar) is the official currency of the United States and its insular territories per the United States Constitution since 1792.
The University of Arizona (also referred to as U of A, UA, or Arizona) is a public research university in Tucson, Arizona.
The University of Arizona Press, a publishing house founded in 1959 as a department of the University of Arizona, is a nonprofit publisher of scholarly and regional books.
The University of Hawaiʻi system (formally the University of Hawaiʻi and popularly known as UH) is a public, co-educational college and university system that confers associate, bachelor's, master's, and doctoral degrees through three university campuses, seven community college campuses, an employment training center, three university centers, four education centers and various other research facilities distributed across six islands throughout the State of Hawaii in the United States.
The University of Nottingham is a public research university in Nottingham, United Kingdom.
The University of Oxford (formally The Chancellor Masters and Scholars of the University of Oxford) is a collegiate research university located in Oxford, England.
Uranium is a chemical element with symbol U and atomic number 92.
Uranus is the seventh planet from the Sun.
Urbain Jean Joseph Le Verrier (11 March 1811 – 23 September 1877) was a French mathematician who specialized in celestial mechanics and is best known for predicting the existence and position of Neptune using only mathematics.
USA Today is an internationally distributed American daily, middle-market newspaper that serves as the flagship publication of its owner, the Gannett Company.
Vapor pressure or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system.
Venetia Katharine Douglas Phair, née Burney (11 July 1918 – 30 April 2009) was an English woman who as a girl was credited by Clyde Tombaugh with first suggesting the name Pluto for the planet he discovered in 1930.
Vesto Melvin Slipher (November 11, 1875 – November 8, 1969) was an American astronomer who performed the first measurements of radial velocities for galaxies, providing the empirical basis for the expansion of the universe.
Voyager 2 is a space probe launched by NASA on August 20, 1977, to study the outer planets.
Walter Elias Disney (December 5, 1901December 15, 1966) was an American entrepreneur, animator, voice actor and film producer.
In Māori mythology, Whiro (or Hiro in the Tuamotus) is the lord of darkness, or the embodiment of all evil.
Wiley-VCH is a German publisher owned by John Wiley & Sons.
William Henry Pickering (February 15, 1858 – January 16, 1938) was an American astronomer.
Yama or Yamarāja is a god of death, the south direction, and the underworld, belonging to an early stratum of Rigvedic Hindu deities.
In East Asian and Buddhist mythology, Yama (sometimes known as the King of Hell, King Yan or Yanluo) is a dharmapala (wrathful god) said to judge the dead and preside over the Narakas ("Hells" or "Purgatories") and the cycle of afterlife saṃsāra.
Yerkes Observatory is an astronomical observatory in Williams Bay, Wisconsin operated by the University of Chicago Department of Astronomy and Astrophysics.
Zeus (Ζεύς, Zeús) is the sky and thunder god in ancient Greek religion, who rules as king of the gods of Mount Olympus.
1163 Saga, provisional designation, is a background asteroid from the outer regions of the asteroid belt, approximately 32 kilometers in diameter.
15810 Arawn, provisional designation, is a trans-Neptunian object (TNO) from the inner regions of the Kuiper belt, approximately in diameter.
Pallas, minor-planet designation 2 Pallas, is the second asteroid to have been discovered (after Ceres), and is one of the largest asteroids in the Solar System.
2018 has been designated as the third International Year of the Reef by the International Coral Reef Initiative.
2019 (MMXIX) will be a common year starting on Tuesday of the Gregorian calendar, the 2019th year of the Common Era (CE) and Anno Domini (AD) designations, the 19th year of the 3rd millennium, the 19th year of the 21st century, and the 10th and last year of the 2010s decade.
Juno, minor-planet designation 3 Juno in the Minor Planet Center catalogue system, is an asteroid in the asteroid belt.
Vesta, minor-planet designation 4 Vesta, is one of the largest objects in the asteroid belt, with a mean diameter of.
617 Patroclus, provisional designation is a binary Jupiter trojan approximately in diameter.
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