Small Solar System Bodies
In astronomy , a small solar system bodies is a celestial object of solar system orbiting the Sun and who is not a planet or a dwarf planet Definition The International Astronomical Union , an organization responsible for astronomical nomenclature, specifies a small body as a celestial body of the solar system that meets the following conditions Features The IAU definition only applies to objects directly in orbit around the Sun. It does not apply to natural satellites of planets, dwarf planets or even other small bodies. However, this definition does not clarify the status of binary objects which each member is of similar size and orbit around each other, the whole system orbiting the sun. Several items of this type are known, such as the asteroid (90) Antiope. The IAU definition does not specify size limits, both lower and upper. The upper and lower limits in size and mass of dwarf planets are not specified in Resolution 5A of the International Astronomical Union. Strictly speaking, there is no upper limit and an object larger and more massive than Mercury , which has not "cleared the neighborhood around its orbit" can be categorized as a dwarf planet. The upper limit is determined by the concept of " hydrostatic equilibrium ", but the dimensions to which an item reaches such a state are not determined, empirical observations suggest that they vary depending on the composition and history of the object. The initial version of the resolution 5 defined as applying hydrostatic equilibrium "objects whose mass exceeds 5 10 20 kg (500 million billion tons) and 800 km diameter" , but this does was not retained in the final resolution. By comparison, among the moons of giant planets, a body as large as Proteus , a satellite of Neptune measuring over 400 km of medium diameter, do not have a spherical shape. However, Mimas , satellite of Saturn of comparable size, is clearly spherical. No lower limit is specified. The smallest macroscopic objects orbiting the Sun are called meteoroids. Below this size, there are interplanetary dust , the molecules and single atoms. It is not clear whether the small bodies together all of these objects. The definition of a small body uses of a planet and a dwarf planet and guess she has not "made a clean sweep in its vicinity, but does not explain this concept further. Alan Stern and Harold F. Levison have defined a criterion to distinguish between a planet and a dwarf planet , expressing the probability of an encounter between an object and a smaller body in response to a deviation from the orbit of the latter. According to its authors, this criterion allows to estimate the capacity of a body to clean his neighborhood. Stern and Levison found a gap of five orders of magnitude from its value in March and one of the largest trans-Neptunian asteroids. Using this work, Steven Soter proposed a parameter called discriminant warming, to make the distinction between dwarf planets and the eight planets of the solar system, based on their ability to cleanse the body smaller collision, capture or disturbance gravity . These criteria could apply a fortiori to the small bodies. The orbits of the vast majority of small solar system bodies are localized in two distinct regions, the asteroid belt and the Kuiper Belt. Other regions contain lower concentrations of small bodies like asteroids NEOs , the centaurs , the comets or isolated objects. Orbit
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Types Asteroid binary asteroids asteroid moons Comet Asteroid comet Internal orbital classes Vulcanoids Near-Earth Main belt Trojan External orbital classes Centaur Damocloids Trans- ( Kuiper Belt Subject scattered Subject seconded Hills Cloud Oort Cloud ) Subclasses Lists: Plutino plutoids Haumea Family scattered Subject See also: List of asteroids of the Solar System
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