283 relations: Abū Ishāq Ibrāhīm al-Zarqālī, Accretion (astrophysics), Aerobraking, Al-Andalus, Albedo, Albert Einstein, Ancient Greece, Antarctica, Antipodal point, Antipodes, Apollodorus (crater), Apparent magnitude, Apparent place, Apparent retrograde motion, Applied Physics Laboratory, Apsidal precession, Arecibo Observatory, Argon, Assyria, Asteroid, Astronomical symbols, Astronomical unit, Astronomy in the medieval Islamic world, Atmosphere, Avempace, Aviation Week & Space Technology, Axial tilt, Babylonia, Babylonian astronomy, Babylonian religion, Beethoven (crater), BepiColombo, Bond albedo, Budha, Caduceus, Calcium, Caloris Planitia, Carbon dioxide, Chaos theory, Chinese culture, Chondrite, Classical mechanics, Cold trap (astronomy), Comet, Comet Encke, Complex volcano, Crescent, Crust (geology), Culture of Japan, Culture of Korea, ..., Culture of Vietnam, Cuneiform script, Day, Delta-v, Diffusion, Dipole, Drag (physics), Dwarf planet, Dynamo, Dynamo theory, E. M. Antoniadi, Earth, Ecliptic, Elongation (astronomy), Epoch (astronomy), Equator, Escape velocity, Escarpment, European Space Agency, Exosphere, Exploration of Mercury, Fixed stars, Flux transfer event, Formation and evolution of the Solar System, Fossa (geology), Frame of reference, Friedrich Bessel, G-force, Galileo Galilei, Gamma ray, Ganymede (moon), General relativity, Geology of Mercury, Geology of solar terrestrial planets, Geometric albedo, Germanic paganism, Giant-impact hypothesis, Giovanni Battista Zupi, Giovanni Schiaparelli, Giuseppe Colombo, Goldstone Solar System Radar, Gordon Pettengill, Gravitational compression, Gravity, Gravity assist, Greek language, Haumea, Helium, Helium atom, Hermes, Highland, Hindu mythology, History of China, Hohmann transfer orbit, Homogeneity and heterogeneity, Horizontal coordinate system, Houghton Mifflin Harcourt, Hubble Space Telescope, Hun Kal (crater), Hydrogen, Hydrogen atom, Hydroxide, Icarus (journal), Ice, Impact crater, Inferior and superior planets, Infrared, Institute of Radio-engineering and Electronics, Inter-crater plains on Mercury, International Astronomical Union, International Celestial Reference Frame, Invariable plane, JAXA, Johann Hieronymus Schröter, Johannes Kepler, John Bevis, JPL Horizons On-Line Ephemeris System, Julian year (astronomy), Jupiter, Kerala School of Astronomy and Mathematics, Kinetic energy, Krypton, Late Heavy Bombardment, Lava, List of albedo features on Mercury, List of craters on Mercury, List of natural satellites, List of Solar System objects by size, Longitude, Lucky imaging, Lunar mare, Lunar phase, Lunar Reconnaissance Orbiter, Magma, Magnesium, Magnetic field, Magnetic reconnection, Magnetometer, Magnetosphere, Mantle (geology), Maragheh observatory, Mariner 10, Mars, Maya civilization, Mercury (mythology), Mercury in fiction, Meridian (astronomy), MESSENGER, Micrometeorite, Middle latitudes, Minute and second of arc, Moon, Mount Wilson Observatory, MUL.APIN, Nabu, NASA, Natural satellite, Nature (journal), Neon, Neptune, Nilakantha Somayaji, Nitrogen, Northern Hemisphere, Occultation, Odin, Opposition surge, Orbit, Orbital eccentricity, Orbital period, Orbital resonance, Orbital speed, Osculating orbit, Outgassing, Outline of Mercury (planet), Oxygen, Perihelion and aphelion, Perturbation (astronomy), Peterson Field Guides, Pierre Gassendi, Pine nut, Plain, Planet, Planetary core, Planetary nomenclature, Planetary phase, Planetesimal, Planets in astrology, Plasma (physics), Pluto, Potassium, Potential energy, Potential well, Precession, Protostar, Ptolemy, Puerto Rico, Pyroclastic flow, Qutb al-Din al-Shirazi, Radar, Radio telescope, Radioactive decay, Radius, Reflection (physics), Regolith, Roman mythology, Rotation, Rotational speed, Royal Astronomical Society of Canada, Royal Observatory, Greenwich, Rupes, Russian Academy of Sciences, Science (journal), Sean Solomon, Secular resonance, Semi-major and semi-minor axes, Shield volcano, Sidereal time, Silicate, Silicon, Sirius, Sodium, Solar constant, Solar eclipse, Solar maximum, Solar sail, Solar System, Solar time, Solar wind, Southern Hemisphere, Space colonization, Space Science Reviews, Space weathering, Space.com, Spacecraft, Spectrometer, Springer Science+Business Media, Sputtering, Sublimation (phase transition), Sun, Sunlight, Sunspot, Telescope, Terrestrial planet, Tesla (unit), The New York Times, Thrust fault, Tidal force, Tidal locking, Timeline of the far future, Titan (moon), Tolstoj (crater), Transit (astronomy), Transit of Mercury, Tycho Brahe, Tychonic system, Ultraviolet, Underworld, Uranus, Urbain Le Verrier, Vallis (planetary geology), Velocity, Venus, Very Large Array, Vladimir Kotelnikov, Volcano, Vulcan (hypothetical planet), Washington, D.C., Water, Wrinkle ridge, Wu Xing, X-ray, Xenon, 1566 Icarus. Expand index (233 more) » « Shrink index
, also known as Al-Zarkali or Ibn Zarqala (1029–1087), was an Arab Muslim instrument maker, astrologer, and one of the leading astronomers of his time.
In astrophysics, accretion is the accumulation of particles into a massive object by gravitationally attracting more matter, typically gaseous matter, in an accretion disk.
Aerobraking is a spaceflight maneuver that reduces the high point of an elliptical orbit (apoapsis) by flying the vehicle through the atmosphere at the low point of the orbit (periapsis).
Al-Andalus (الأنْدَلُس, trans.; al-Ándalus; al-Ândalus; al-Àndalus; Berber: Andalus), also known as Muslim Spain, Muslim Iberia, or Islamic Iberia, was a medieval Muslim territory and cultural domain occupying at its peak most of what are today Spain and Portugal.
Albedo (albedo, meaning "whiteness") is the measure of the diffuse reflection of solar radiation out of the total solar radiation received by an astronomical body (e.g. a planet like Earth).
Albert Einstein (14 March 1879 – 18 April 1955) was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics).
Ancient Greece was a civilization belonging to a period of Greek history from the Greek Dark Ages of the 13th–9th centuries BC to the end of antiquity (AD 600).
Antarctica is Earth's southernmost continent.
In mathematics, the antipodal point of a point on the surface of a sphere is the point which is diametrically opposite to it — so situated that a line drawn from the one to the other passes through the center of the sphere and forms a true diameter.
In geography, the antipode of any spot on Earth is the point on Earth's surface diametrically opposite to it; the antipodes of a region similarly represent the area opposite it.
Apollodorus is an impact crater on Mercury.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
The apparent place of an object is its position in space as seen by an observer.
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.
The Arecibo Observatory is a radio telescope in the municipality of Arecibo, Puerto Rico.
Argon is a chemical element with symbol Ar and atomic number 18.
Assyria, also called the Assyrian Empire, was a major Semitic speaking Mesopotamian kingdom and empire of the ancient Near East and the Levant.
Asteroids are minor planets, especially those of the inner Solar System.
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.
Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age (9th–13th centuries), and mostly written in the Arabic language.
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.
Avempace (– 1138) is the Latinate form of Ibn Bâjja (ابن باجه), full name Abû Bakr Muḥammad Ibn Yaḥyà ibn aṣ-Ṣâ’igh at-Tûjîbî Ibn Bâjja al-Tujibi (أبو بكر محمد بن يحيى بن الصائغ), was an Arab Andalusian polymath: his writings include works regarding astronomy, physics, and music, as well as philosophy, medicine, botany, and poetry.
Aviation Week & Space Technology, often abbreviated Aviation Week or AW&ST, is the flagship magazine of the Aviation Week Network.
In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its equatorial plane and orbital plane.
Babylonia was an ancient Akkadian-speaking state and cultural area based in central-southern Mesopotamia (present-day Iraq).
The history of astronomy in Mesopotamia, and the world, begins with the Sumerians who developed the earliest writing system—known as cuneiform—around 3500–3200 BC.
Babylonian religion is the religious practice of Babylonia.
Beethoven is a crater at latitude 20°S, longitude 124°W on Mercury.
BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury.
The Bond albedo, named after the American astronomer George Phillips Bond (1825–1865), who originally proposed it, is the fraction of power in the total electromagnetic radiation incident on an astronomical body that is scattered back out into space.
Budha graha (बुध) is a Sanskrit word that connotes the planet Mercury.
The caduceus (☤;; Latin cādūceus, from Greek κηρύκειον kērū́keion "herald's wand, or staff") is the staff carried by Hermes in Greek mythology and consequently by Hermes Trismegistus in Greco-Egyptian mythology.
Calcium is a chemical element with symbol Ca and atomic number 20.
Caloris Planitia is a plain within a large impact basin on Mercury, informally named Caloris, about in diameter.
Carbon dioxide (chemical formula) is a colorless gas with a density about 60% higher than that of dry air.
Chaos theory is a branch of mathematics focusing on the behavior of dynamical systems that are highly sensitive to initial conditions.
Chinese culture is one of the world's oldest cultures, originating thousands of years ago.
Chondrites are stony (non-metallic) meteorites that have not been modified due to melting or differentiation of the parent body.
Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars and galaxies.
A cold trap is a concept in Planetary Sciences that describes an area cold enough to freeze (trap) volatiles.
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.
Comet Encke or Encke's Comet (official designation: 2P/Encke) is a periodic comet that completes an orbit of the Sun once every 3.3 years.
A complex volcano, also called a compound volcano, is mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock.
A crescent shape (British English also) is a symbol or emblem used to represent the lunar phase in the first quarter (the "sickle moon"), or by extension a symbol representing the Moon itself.
In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite.
The culture of Japan has evolved greatly over the millennia, from the country's prehistoric time Jōmon period, to its contemporary modern culture, which absorbs influences from Asia, Europe, and North America.
The traditional culture of Korea refers to the shared cultural heritage of the Korean Peninsula.
The cultural of Vietnam (Văn hóa Việt Nam The culture of Vietnam) is one of the oldest in Southeast Asia, with the ancient Bronze age Đông Sơn culture being widely considered one of its most important progenitors.
Cuneiform script, one of the earliest systems of writing, was invented by the Sumerians.
A day, a unit of time, is approximately the period of time during which the Earth completes one rotation with respect to the Sun (solar day).
Delta-v (literally "change in velocity"), symbolised as ∆v and pronounced delta-vee, as used in spacecraft flight dynamics, is a measure of the impulse that is needed to perform a maneuver such as launch from, or landing on a planet or moon, or in-space orbital maneuver.
Diffusion is the net movement of molecules or atoms from a region of high concentration (or high chemical potential) to a region of low concentration (or low chemical potential) as a result of random motion of the molecules or atoms.
In electromagnetism, there are two kinds of dipoles.
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.
A dwarf planet is a planetary-mass object that is neither a planet nor a natural satellite.
A dynamo is an electrical generator that creates direct current using a commutator.
In physics, the dynamo theory proposes a mechanism by which a celestial body such as Earth or a star generates a magnetic field.
Eugène Michel Antoniadi (1 March 1870 – 10 February 1944) was a Greek astronomer.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
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 astronomy, a planet's elongation is the angular separation between the Sun and the planet, with Earth as the reference point.
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).
In physics, escape velocity is the minimum speed needed for an object to escape from the gravitational influence of a massive body.
An escarpment is a steep slope or long cliff that forms as an effect of faulting or erosion and separates two relatively leveled areas having differing elevations.
The European Space Agency (ESA; Agence spatiale européenne, ASE; Europäische Weltraumorganisation) is an intergovernmental organisation of 22 member states dedicated to the exploration of space.
The exosphere (ἔξω éxō "outside, external, beyond", σφαῖρα sphaĩra "sphere") is a thin, atmosphere-like volume surrounding a planet or natural satellite where molecules are gravitationally bound to that body, but where the density is too low for them to behave as a gas by colliding with each other.
The exploration of Mercury has played only a minor role in the space interests of the world.
The fixed stars (stellae fixae) comprise the background of astronomical objects that appear to not move relative to each other in the night sky compared to the foreground of Solar System objects that do.
A flux transfer event (FTE) occurs when a magnetic portal opens in the Earth's magnetosphere through which high-energy particles flow from the Sun.
The formation and evolution of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud.
In planetary geology, a fossa (pl. fossae) is a long, narrow depression (trough) on the surface of an extraterrestrial body, such as a planet or moon.
In physics, a frame of reference (or reference frame) consists of an abstract coordinate system and the set of physical reference points that uniquely fix (locate and orient) the coordinate system and standardize measurements.
Friedrich Wilhelm Bessel (22 July 1784 – 17 March 1846) was a German astronomer, mathematician, physicist and geodesist.
The gravitational force, or more commonly, g-force, is a measurement of the type of acceleration that causes a perception of weight.
Galileo Galilei (15 February 1564Drake (1978, p. 1). The date of Galileo's birth is given according to the Julian calendar, which was then in force throughout Christendom. In 1582 it was replaced in Italy and several other Catholic countries with the Gregorian calendar. Unless otherwise indicated, dates in this article are given according to the Gregorian calendar. – 8 January 1642) was an Italian polymath.
A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.
Ganymede (Jupiter III) is the largest and most massive moon of Jupiter and in the Solar System.
General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics.
The geology of Mercury is the least understood of all the terrestrial planets in the Solar System.
The geology of solar terrestrial planets mainly deals with the geological aspects of the four terrestrial planets of the Solar System, Mercury, Venus, Earth, and Mars, and one terrestrial dwarf planet, Ceres.
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.
Germanic religion refers to the indigenous religion of the Germanic peoples from the Iron Age until Christianisation during the Middle Ages.
The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact suggests that the Moon formed out of the debris left over from a collision between Earth and an astronomical body the size of Mars, approximately 4.5 billion years ago, in the Hadean eon; about 20 to 100 million years after the solar system coalesced.
Giovanni Battista Zupi or Zupus (c. 1590 – 1650) was an Italian astronomer, mathematician, and Jesuit priest.
Giovanni Virginio Schiaparelli FRS(For) HFRSE (14 March 1835 Savigliano – 4 July 1910 Milan) was an Italian astronomer and science historian.
Giuseppe Colombo (Padua, October 2, 1920 – Padua, February 20, 1984), better known by his nickname Bepi Colombo, was an Italian scientist, mathematician and engineer at the University of Padua, Italy.
The Goldstone Solar System Radar, or GSSR, is a large radar system used for investigating objects in the Solar system.
Gordon H. Pettengill (born February 10, 1926) is an American radio astronomer and planetary physicist.
Gravitational compression is a phenomenon in which gravity, acting on the mass of an object, compresses it, reducing its size and increases the object's density.
Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.
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.
Greek (Modern Greek: ελληνικά, elliniká, "Greek", ελληνική γλώσσα, ellinikí glóssa, "Greek language") is an independent branch of the Indo-European family of languages, native to Greece and other parts of the Eastern Mediterranean and the Black Sea.
Haumea, minor-planet designation 136108 Haumea, is a dwarf planet located beyond Neptune's orbit.
Helium (from lit) is a chemical element with symbol He and atomic number 2.
A helium atom is an atom of the chemical element helium.
Hermes (Ἑρμῆς) is an Olympian god in Greek religion and mythology, the son of Zeus and the Pleiad Maia, and the second youngest of the Olympian gods (Dionysus being the youngest).
Highlands or uplands are any mountainous region or elevated mountainous plateau.
Hindu mythology are mythical narratives found in Hindu texts such as the Vedic literature, epics like Mahabharata and Ramayana, the Puranas, the regional literatures Sangam literature and Periya Puranam.
The earliest known written records of the history of China date from as early as 1250 BC,William G. Boltz, Early Chinese Writing, World Archaeology, Vol.
In orbital mechanics, the Hohmann transfer orbit is an elliptical orbit used to transfer between two circular orbits of different radii in the same plane.
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity in a substance or organism.
The horizontal coordinate system is a celestial coordinate system that uses the observer's local horizon as the fundamental plane.
Houghton Mifflin Harcourt (HMH) is an educational and trade publisher in the United States.
The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.
Hun Kal is a small crater on Mercury that serves as the reference point for the planet's system of longitude.
Hydrogen is a chemical element with symbol H and atomic number 1.
A hydrogen atom is an atom of the chemical element hydrogen.
Hydroxide is a diatomic anion with chemical formula OH−.
Icarus is a scientific journal dedicated to the field of planetary science.
Ice is water frozen into a solid state.
An impact crater is an approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body.
In the Solar System, a planet is said to be inferior with respect to another planet if its orbit lies inside the other planet's orbit around the Sun.
Infrared radiation (IR) is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore generally invisible to the human eye (although IR at wavelengths up to 1050 nm from specially pulsed lasers can be seen by humans under certain conditions). It is sometimes called infrared light.
Institute of Radio-engineering and Electronics (Институт радиотехники и электроники (ИРЭ)) by the Russian Academy of Science is an institute in Moscow, that conducts fundamental research in fields of radiophysics, radiotechnics, physical and quantum electronics, informatics.
Inter-crater plains on Mercury are a land-form consisting of plains between craters on Mercury.
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 astrometry, an International Celestial Reference Frame (ICRF) is a realization of the International Celestial Reference System (ICRS) using reference celestial sources observed at radio wavelengths.
The invariable plane of a planetary system, also called Laplace's invariable plane, is the plane passing through its barycenter (center of mass) perpendicular to its angular momentum vector.
The is the Japanese national aerospace and space agency.
Johann Hieronymus Schröter (30 August 1745, Erfurt – 29 August 1816, Lilienthal) was a German astronomer.
Johannes Kepler (December 27, 1571 – November 15, 1630) was a German mathematician, astronomer, and astrologer.
John Bevis (10 November 1695 in Salisbury, Wiltshire – 6 November 1771) was an English doctor, electrical researcher and 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 Kerala School of Astronomy and Mathematics was a school of mathematics and astronomy founded by Madhava of Sangamagrama in Kerala, India, which included among its members: Parameshvara, Neelakanta Somayaji, Jyeshtadeva, Achyuta Pisharati, Melpathur Narayana Bhattathiri and Achyuta Panikkar.
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
Krypton (from translit "the hidden one") is a chemical element with symbol Kr and atomic number 36.
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.
Lava is molten rock generated by geothermal energy and expelled through fractures in planetary crust or in an eruption, usually at temperatures from.
This is a list of the albedo features of the planet Mercury as seen by early telescopic observation.
This is a list of named craters on Mercury, the innermost planet of the Solar System (for other features, see list of geological features on Mercury).
The Solar System's planets and officially recognized dwarf planets are known to be orbited by 184 natural satellites, or moons.
This is a partial list of Solar System objects by size, arranged in descending order of mean volumetric radius, and subdivided into several size classes.
Longitude, is a geographic coordinate that specifies the east-west position of a point on the Earth's surface.
Lucky imaging (also called lucky exposures) is one form of speckle imaging used for astronomical photography.
The lunar maria (singular: mare) are large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions.
The lunar phase or phase of the Moon is the shape of the directly sunlit portion of the Moon as viewed from Earth.
The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit.
Magma (from Ancient Greek μάγμα (mágma) meaning "thick unguent") is a mixture of molten or semi-molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets and some natural satellites.
Magnesium is a chemical element with symbol Mg and atomic number 12.
A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials.
Magnetic reconnection is a physical process in highly conducting plasmas in which the magnetic topology is rearranged and magnetic energy is converted to kinetic energy, thermal energy, and particle acceleration.
A magnetometer is an instrument that measures magnetism—either the magnetization of a magnetic material like a ferromagnet, or the direction, strength, or relative change of a magnetic field at a particular location.
A magnetosphere is the region of space surrounding an astronomical object in which charged particles are manipulated or affected by that object's magnetic field.
The mantle is a layer inside a terrestrial planet and some other rocky planetary bodies.
Maragheh observatory (رصدخانه مراغه), was an institutionalized astronomical observatory which was established in 1259 CE under the patronage of the Ilkhanid Hulagu and the directorship of Nasir al-Din al-Tusi, a Persian scientist and astronomer.
Mariner 10 was an American robotic space probe launched by NASA on November 3, 1973, to fly by the planets Mercury and Venus.
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury.
The Maya civilization was a Mesoamerican civilization developed by the Maya peoples, and noted for its hieroglyphic script—the only known fully developed writing system of the pre-Columbian Americas—as well as for its art, architecture, mathematics, calendar, and astronomical system.
Mercury (Latin: Mercurius) is a major god in Roman religion and mythology, being one of the Dii Consentes within the ancient Roman pantheon.
The planet Mercury has often been used as a setting in science fiction.
In astronomy, the meridian is the great circle passing through the celestial poles, the zenith, and the nadir of an observer's location.
Messenger (stylized as MESSENGER, whose backronym is "MErcury Surface, Space ENvironment, GEochemistry, and Ranging", and which is a reference to the messenger of the same name from Roman mythology) was a NASA robotic spacecraft that orbited the planet Mercury between 2011 and 2015.
A micrometeorite is essentially a micrometeoroid that has survived entry through Earth's atmosphere.
The middle latitudes (also called the mid-latitudes, sometimes midlatitudes, or moderate latitudes) of Earth lie between 23°26'22" and 66°33'39" north, and between 23°26'22" and 66°33'39" south.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite.
The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States.
MUL.APIN is the conventional title given to a Babylonian compendium that deals with many diverse aspects of Babylonian astronomy and astrology.
Nabu (cuneiform: 𒀭𒀝 Nabū ܢܒܘ) is the ancient Mesopotamian patron god of literacy, the rational arts, scribes and wisdom.
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.
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).
Nature is a British multidisciplinary scientific journal, first published on 4 November 1869.
Neon is a chemical element with symbol Ne and atomic number 10.
Neptune is the eighth and farthest known planet from the Sun in the Solar System.
Kelallur Nilakantha Somayaji (also referred to as Kelallur Comatiri; 14 June 1444 – 1544) was a major mathematician and astronomer of the Kerala school of astronomy and mathematics in India.
Nitrogen is a chemical element with symbol N and atomic number 7.
The Northern Hemisphere is the half of Earth that is north of the Equator.
An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer.
In Germanic mythology, Odin (from Óðinn /ˈoːðinː/) is a widely revered god.
The opposition surge (sometimes known as the opposition effect, opposition spike or Seeliger effect) is the brightening of a rough surface, or an object with many particles, when illuminated from directly behind the observer.
In physics, an orbit is the gravitationally curved trajectory of an object, such as the trajectory of a planet around a star or a natural satellite around a planet.
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.
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
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 gravitationally bound systems, the orbital speed of an astronomical body or object (e.g. planet, moon, artificial satellite, spacecraft, or star) is the speed at which it orbits around either the barycenter or, if the object is much less massive than the largest body in the system, its speed relative to that largest body.
In astronomy, and in particular in astrodynamics, the osculating orbit of an object in space at a given moment in time is the gravitational Kepler orbit (i.e. ellipse or other conic) that it would have about its central body if perturbations were not present.
Outgassing (sometimes called offgassing, particularly when in reference to indoor air quality) is the release of a gas that was dissolved, trapped, frozen or absorbed in some material.
The following outline is provided as an overview of and topical guide to Mercury: Mercury – smallest and innermost planet in the Solar System.
Oxygen is a chemical element with symbol O and atomic number 8.
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.
The Peterson Field Guides (PFG) are a popular and influential series of American field guides intended to assist the layman in identification of birds, plants, insects and other natural phenomena.
Pierre Gassendi (also Pierre Gassend, Petrus Gassendi; 22 January 1592 – 24 October 1655) was a French philosopher, priest, astronomer, and mathematician.
Pine nuts (also called piñon or pignoli /pinˈyōlē/) are the edible seeds of pines (family Pinaceae, genus Pinus).
In geography, a plain is a flat, sweeping landmass that generally does not change much in elevation.
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.
Planetary nomenclature, like terrestrial nomenclature, is a system of uniquely identifying features on the surface of a planet or natural satellite so that the features can be easily located, described, and discussed.
A planetary phase is a period of time during which a certain portion of a planet's area reflects sunlight from the perspective of a given vantage point.
Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks.
Planets in astrology have a meaning different from the modern astronomical understanding of what a planet is.
Plasma (Henry George Liddell, Robert Scott, A Greek English Lexicon, on Perseus) is one of the four fundamental states of matter, and was first described by chemist Irving Langmuir in the 1920s.
Pluto (minor planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune.
Potassium is a chemical element with symbol K (from Neo-Latin kalium) and atomic number 19.
In physics, potential energy is the energy possessed by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.
A potential well is the region surrounding a local minimum of potential energy.
Precession is a change in the orientation of the rotational axis of a rotating body.
A protostar is a very young star that is still gathering mass from its parent molecular cloud.
Claudius Ptolemy (Κλαύδιος Πτολεμαῖος, Klaúdios Ptolemaîos; Claudius Ptolemaeus) was a Greco-Roman mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology.
Puerto Rico (Spanish for "Rich Port"), officially the Commonwealth of Puerto Rico (Estado Libre Asociado de Puerto Rico, "Free Associated State of Puerto Rico") and briefly called Porto Rico, is an unincorporated territory of the United States located in the northeast Caribbean Sea.
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that moves away from a volcano reaching speeds of up to.
Qotb al-Din Mahmoud b. Zia al-Din Mas'ud b. Mosleh Shirazi (1236—1311) (قطبالدین محمود بن ضیاالدین مسعود بن مصلح شیرازی) was a 13th-century Iranian polymath and poet who made contributions to astronomy, mathematics, medicine, physics, music theory, philosophy and Sufism.
Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects.
A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky in radio astronomy.
Radioactive decay (also known as nuclear decay or radioactivity) is the process by which an unstable atomic nucleus loses energy (in terms of mass in its rest frame) by emitting radiation, such as an alpha particle, beta particle with neutrino or only a neutrino in the case of electron capture, gamma ray, or electron in the case of internal conversion.
In classical geometry, a radius of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated.
Regolith is a layer of loose, heterogeneous superficial deposits covering solid rock.
Roman mythology is the body of traditional stories pertaining to ancient Rome's legendary origins and religious system, as represented in the literature and visual arts of the Romans.
A rotation is a circular movement of an object around a center (or point) of rotation.
Rotational speed (or speed of revolution) of an object rotating around an axis is the number of turns of the object divided by time, specified as revolutions per minute (rpm), cycles per second (cps), radians per second (rad/s), etc..
The Royal Astronomical Society of Canada (RASC) is a national, non-profit, charitable organization devoted to the advancement of astronomy and related sciences.
The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, moved from Greenwich to Herstmonceux) is an observatory situated on a hill in Greenwich Park, overlooking the River Thames.
Rupes is the Latin word for 'cliff' (the same form rupes is both singular and plural).
The Russian Academy of Sciences (RAS; Росси́йская акаде́мия нау́к (РАН) Rossíiskaya akadémiya naúk) consists of the national academy of Russia; a network of scientific research institutes from across the Russian Federation; and additional scientific and social units such as libraries, publishing units, and hospitals.
Science, also widely referred to as Science Magazine, is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals.
Sean Carl Solomon (born 1945) is the director of the Lamont-Doherty Earth Observatory of Columbia University, where he is also the William B. Ransford Professor of Earth and Planetary Science.
A secular resonance is a type of orbital resonance of two bodies with a synchronized precession.
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.
A shield volcano is a type of volcano usually composed almost entirely of fluid lava flows.
Sidereal time is a timekeeping system that astronomers use to locate celestial objects.
In chemistry, a silicate is any member of a family of anions consisting of silicon and oxygen, usually with the general formula, where 0 ≤ x Silicate anions are often large polymeric molecules with an extense variety of structures, including chains and rings (as in polymeric metasilicate), double chains (as in, and sheets (as in. In geology and astronomy, the term silicate is used to mean silicate minerals, ionic solids with silicate anions; as well as rock types that consist predominantly of such minerals. In that context, the term also includes the non-ionic compound silicon dioxide (silica, quartz), which would correspond to x.
Silicon is a chemical element with symbol Si and atomic number 14.
Sirius (a romanization of Greek Σείριος, Seirios,."glowing" or "scorching") is a star system and the brightest star in the Earth's night sky.
Sodium is a chemical element with symbol Na (from Latin natrium) and atomic number 11.
The solar constant is a flux density measuring mean solar electromagnetic radiation (solar irradiance) per unit area.
A solar eclipse (as seen from the planet Earth) is a type of eclipse that occurs when the Moon passes between the Sun and Earth, and when the Moon fully or partially blocks ("occults") the Sun.
Solar maximum or solar max is a regular period of greatest Sun activity during the 11-year solar cycle.
Solar sails (also called light sails or photon sails) are a proposed method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors.
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.
The Southern Hemisphere is the half of Earth that is south of the Equator.
Space colonization (also called space settlement, or extraterrestrial colonization) is permanent human habitation off the planet Earth.
Space Science Reviews is a peer reviewed, scientific journal of space science.
Space weathering is the type of weathering that occurs to any object exposed to the harsh environment of outer space.
Space.com is a space and astronomy news website.
A spacecraft is a vehicle or machine designed to fly in outer space.
A spectrometer is a scientific instrument used to separate and measure spectral components of a physical phenomenon.
Springer Science+Business Media or Springer, part of Springer Nature since 2015, is a global publishing company that publishes books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing.
Sputtering is a process whereby particles are ejected from a solid target material due to bombardment of the target by energetic particles, particularly gas ions in a laboratory.
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.
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light.
Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas.
A telescope is an optical instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light).
A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals.
The tesla (symbol T) is a derived unit of magnetic flux density (informally, magnetic field strength) in the International System of Units.
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.
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks.
The tidal force is an apparent force that stretches a body towards the center of mass of another body due to a gradient (difference in strength) in gravitational field from the other body; it is responsible for the diverse phenomena, including tides, tidal locking, breaking apart of celestial bodies and formation of ring systems within Roche limit, and in extreme cases, spaghettification of objects.
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.
While predictions of the future can never be absolutely certain, present understanding in various scientific fields allows for the prediction of far-future events, if only in the broadest outline.
Titan is the largest moon of Saturn.
Tolstoj is a large, ancient impact crater at latitude −15, longitude 165 on Mercury.
In astronomy, a transit or astronomical transit is the phenomenon of at least one celestial body appearing to move across the face of another celestial body, hiding a small part of it, as seen by an observer at some particular vantage point.
A transit of Mercury across the Sun takes place when the planet Mercury passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk.
Tycho Brahe (born Tyge Ottesen Brahe;. He adopted the Latinized form "Tycho Brahe" (sometimes written Tÿcho) at around age fifteen. The name Tycho comes from Tyche (Τύχη, meaning "luck" in Greek, Roman equivalent: Fortuna), a tutelary deity of fortune and prosperity of ancient Greek city cults. He is now generally referred to as "Tycho," as was common in Scandinavia in his time, rather than by his surname "Brahe" (a spurious appellative form of his name, Tycho de Brahe, only appears much later). 14 December 154624 October 1601) was a Danish nobleman, astronomer, and writer known for his accurate and comprehensive astronomical and planetary observations.
The Tychonic system (or Tychonian system) is a model of the Solar system published by Tycho Brahe in the late 16th century which combines what he saw as the mathematical benefits of the Copernican system with the philosophical and "physical" benefits of the Ptolemaic system.
Ultraviolet (UV) is electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays.
The underworld is the world of the dead in various religious traditions, located below the world of the living.
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.
Vallis (plural valles) is the Latin word for valley.
The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time.
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.
The Karl G. Jansky Very Large Array (VLA) is a centimeter-wavelength radio astronomy observatory located in central New Mexico on the Plains of San Agustin, between the towns of Magdalena and Datil, ~50 miles (80 km) west of Socorro.
Vladimir Aleksandrovich Kotelnikov (Russian Владимир Александрович Котельников, scientific transliteration Vladimir Alexandrovič Kotelnikov, 6 September 1908 in Kazan – 11 February 2005 in Moscow) was an information theory and radar astronomy pioneer from the Soviet Union.
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
Vulcan is a small hypothetical planet that was proposed to exist in an orbit between Mercury and the Sun.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington or D.C., is the capital of the United States of America.
Water is a transparent, tasteless, odorless, and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms.
A wrinkle ridge is a type of feature commonly found on lunar maria.
The Wu Xing, also known as the Five Elements, Five Phases, the Five Agents, the Five Movements, Five Processes, the Five Steps/Stages and the Five Planets of significant gravity: Jupiter-木, Saturn-土, Mercury-水, Venus-金, Mars-火Dr Zai, J..
X-rays make up X-radiation, a form of electromagnetic radiation.
Xenon is a chemical element with symbol Xe and atomic number 54.
1566 Icarus, provisional designation, is an extremely eccentric asteroid, approximately 1.4 kilometers in diameter.
Astronomy Mercury, De Graft (crater), Hermian, Hermiocentric orbit, History of Mercury (planet), Holst (crater), Low-mass high-density planet, Mercurian, Mercurio (planet), Mercury (Planet), Mercury (astronomy), Mercury (dwarf planet), Mercury Planet, Mercury perihelion, Mercury planet, Mercury the planet, Mercury's orbit, Mercury's orbit and rotation, Mercury/Planet, Orbit of Mercury, Planet Mercury, Sol 1, Sol I, Sol b, Sol-1, Structure of Mercury, Suisei (mythology), Sun b, The planet Mercury, Water Star.