NationMaster - Encyclopedia: Planetology

Planetary science, also known as planetology or planetary astronomy, is the science of planets and the solar system, and incorporates an interdisciplinary approach drawing from diverse sciences. Planetary science may be considered a part of the Earth sciences, or more logically, as its parent field. Research tends to be done by a combination of astronomy, space exploration (particularly unmanned space missions), and comparative, experimental and meteorite work based on Earth. There is also an important theoretical component and considerable use of computer simulation. What is science? There are different theories of what science is. ... A planet (from the Greek πλανήτης, planētēs or wanderers) is a body of considerable mass that orbits a star and that produces no energy through nuclear fusion. ... Mosaic of the planets of the solar system, excluding Pluto, and including Earths Moon. ... Interdisciplinary work is that which integrates concepts across different disciplines. ... Earth science (also known as geoscience or the geosciences), is an all-embracing term for the sciences related to the planet Earth. ... Astronomy (Greek: αστρονομία = άστρον + νόμος, literally, law of the stars) is the science involving the observation and explanation of events occurring beyond the Earth and its atmosphere. ... Space exploration is the physical exploration of outer-Earth objects and generally anything that involves the technologies, science, and politics regarding space endeavors. ... Unmanned space missions are those using remote-controlled spacecraft. ... Worlds second largest Meteorite in Culiacan, Mexico A meteorite is a relatively small extra-terrestrial body that reaches the Earths surface. ... The word theory has a number distinct meanings depending on the context. ... A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ...

Planetary science studies objects ranging in size from micrometeoroids to gas giants, their composition, dynamics and history. A Micrometeoroid (also micrometeorite, micrometeor) is a tiny meteoroid; a small particle of rock from space, usually weighing less than a gram, that poses a threat to space exploration. ... A gas giant is a large planet that is not composed mostly of rock or other solid matter. ...

When the discipline concerns itself with a celestial body in particular, a specialised term is used, as shown in the table below (only Heliology, Earth science, Selenology, and Areology are currently in common use):

Body	Term
Sun	Heliology
Mercury	Hermeology
Venus	Cytherology
Earth	Earth science
Moon	Selenology
Mars	Areology
Jupiter	Zenology
Saturn	Kronology
Uranus	Uranology
Neptune	Poseidology
Pluto	Hadeology

Basic Concepts: A Sun is the star at the centre of a solar system. ... Atmospheric characteristics Atmospheric pressure trace Potassium 31. ... (*min temperature refers to cloud tops only) Atmospheric characteristics Atmospheric pressure 9. ... Earth, also known as the Earth or Terra, is the third planet outward from the Sun. ... Earth science (also known as geoscience or the geosciences), is an all-embracing term for the sciences related to the planet Earth. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... Atmospheric characteristics Atmospheric pressure 120 kPa Hydrogen 83% Helium 15% Methane 1. ... Atmospheric characteristics Atmospheric pressure 100-300 kPa Hydrogen >84% Helium >12% Methane 2% Ammonia 0. ... Atmospheric characteristics Atmospheric pressure 0. ...

planet

General subfields within astronomy A planet (from the Greek πλανήτης, planētēs or wanderers) is a body of considerable mass that orbits a star and that produces no energy through nuclear fusion. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... Brown dwarfs are sub-stellar objects (~5 to 90 Jupiter masses) that do not fuse hydrogen into helium in their cores, as do stars on the main sequence, but have fully convective surfaces and interiors, with no chemical differentiation by depth. ... Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small astronomical object similar to an asteroid but composed largely of ice. ... Global earthquake epicenters, 1963–1998 An earthquake is a trembling or a shaking movement of the Earths surface. ... An equatorial bulge is a planetological term which describes a bulge which a planet may have around its equator, distorting it into an oblate spheroid. ... Infrared image of the star GQ Lupi (A) orbited by a planet (b) at a distance of approximately 20 times the distance between Jupiter and our Sun. ... A gas giant is a large planet that is not composed mostly of rock or other solid matter. ... Icy moons are believed to be a common class of planetoids that have a surface mostly of ice, possibly with an ocean under the ice, and possibly including a rocky core of silicate or metallic rocks. ... The Kuiper belt (KYE per) is an area of the solar system extending from within the orbit of Neptune (at 30 AU) to 50 AU from the sun, at inclinations consistent with the ecliptic. ... A magnetosphere is the region around an astronomical object, in which phenomena are dominated by its magnetic field. ... In cosmogony, planetary differentiation is a process by which the denser portions of a planet will sink to the center; while less dense materials rise to the surface. ... Atmospheric characteristics Atmospheric pressure 0. ... Precession (also called gyroscopic precession) is the phenomenon by which the axis of a spinning object (e. ... Space weather is the speed and density of the particles and solar wind currently being generated by the sun. ... A Sun is the star at the centre of a solar system. ... In astronomy, synchronous rotation is a planetological term describing a body orbiting another, where the orbiting body takes as long to rotate on its axis as it does to make one orbit; and therefore always keeps the same hemisphere pointed at the body it is orbiting. ... A terrestrial planet or telluric planet is a planet which is primarily composed of silicate rocks. ... Astronomy (Greek: αστρονομία = άστρον + νόμος, literally, law of the stars) is the science involving the observation and explanation of events occurring beyond the Earth and its atmosphere. ...

(http://en.wikipedia.org/w/wiki.phtml?title=Template:Astronomy-footer&action=edit)

Astrometry is a part of Astronomy and deals with the positions of stars and other celestial bodies, their distances and movements. ... Spiral Galaxy ESO 269-57 Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties ( luminosity, density, temperature and chemical composition) of astronomical objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ... Cosmology is the study of the large-scale structure and history of the universe. ... Galactic astronomy is the study of galaxies, their formation, structure, components, dynamics, interactions, and the range of forms they take. ... Extragalactic Astronomy is the branch of astronomy concerned with objects outside of our own Milky Way Galaxy. ... In astrophysics, the questions of galaxy formation and evolution are: How, from a homogeneous universe, did we obtain the very inhomogeneous one we live in? How did galaxies form? How do galaxies change over time? The formation of galaxies is still one of the most active research areas in astrophysics... Stellar astronomy is the study of stars and the phenomena exhibited by the various forms/developmental stages of stars. ... In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime, the millions or billions of years during which it emits light and heat. ... Star formation is the process by which gas in molecular clouds gets transformed into stars. ...