Draft:Outline of planets

The following outline is provided as an overview of and topical guide to planets:

A planet is a large, rounded astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets by the most restrictive definition of the term: the terrestrial planets Mercury, Venus, Earth, and Mars, and the giant planets Jupiter, Saturn, Uranus, and Neptune. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young protostar orbited by a protoplanetary disk. Planets grow in this disk by the gradual accumulation of material driven by gravity, a process called accretion.

Planetary science (or more rarely, planetology) is the scientific study of planets (including Earth), celestial bodies (such as moons, asteroids, comets) and planetary systems (in particular those of the Solar System) and the processes of their formation. It studies objects ranging in sizes from micrometeoroids to huge gas giants, with the aim of determining their composition, dynamics, formation, interrelations and history. It is a strongly interdisciplinary field, which originally grew from astronomy and Earth science, and now incorporates many disciplines, including planetary geology, cosmochemistry, atmospheric science, physics, oceanography, hydrology, theoretical planetary science, glaciology, and exoplanetology. Allied disciplines include space physics, when concerned with the effects of the Sun on the bodies of the Solar System, and astrobiology.

What type of thing are planets?

Planets can be described as all of the following:

Planetary science – scientific study of planets. Branches of planetary science include:

Orbit –
- Heliocentric orbit – orbit around the barycenter of the Solar System, which is usually located within or very near the surface of the Sun. All planets, comets, and asteroids in the Solar System are in such orbits, as are many artificial probes and pieces of debris. The moons of planets in the Solar System, by contrast, are not in heliocentric orbits as they orbit their respective planet.
Planetary habitability – The measure of a planet's ability to sustain life.

Lists of planets – A list of lists of planets sorted by diverse attributes

Lunar and Planetary Science Conference (LPSC) – organized by the Lunar and Planetary Institute in Houston. Held annually since 1970, occurs in March.
Division for Planetary Sciences (DPS) – meeting held annually since 1970 at a different location each year, predominantly within the mainland US. Occurs around October.
American Geophysical Union (AGU) – annual Fall meeting in December in San Francisco.
American Geophysical Union (AGU) – Joint Assembly (co-sponsored with other societies) in April–May, in various locations around the world.
Meteoritical Society – annual meeting, held during the Northern Hemisphere summer, generally alternating between North America and Europe.
European Planetary Science Congress (EPSC) – held annually around September at a location within Europe.