Rafy
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- 2005
- Uni Grad
- 2008
"Pluto, formerly the solar system's smallest planet, has been stripped of its status by the International Astronomical Union, reducing the number of planets to eight."
(1) A "planet" [1] is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
(2) A "dwarf planet" is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape [2], (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects [3] except satellites orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".
Footnotes:
[1] The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
The Definition of planetPluto loses status as a planet
Astronomers meeting in the Czech capital have voted to strip Pluto of its status as a planet.
About 2,500 experts were in Prague for the International Astronomical Union's (IAU) general assembly.
Astronomers rejected a proposal that would have retained Pluto as a planet and brought three other objects into the cosmic club.
Pluto has been considered a planet since its discovery in 1930 by the American Clyde Tombaugh.
The ninth planet will now effectively be airbrushed out of school and university textbooks.
The decision was made at a meeting of the International Astronomical Union (IAU) in Prague. The astronomers voted by raising their yellow ballot papers for a count.
"The eight planets are Mercury, Earth, Venus, Mars, Jupiter, Saturn, Uranus and Neptune," said the IAU resolution, which was passed following a week of stormy debate. [...]
http://news.bbc.co.uk/2/hi/science/nature/5282440.stm
(1) A "planet" [1] is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
(2) A "dwarf planet" is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape [2], (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects [3] except satellites orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".
Footnotes:
[1] The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
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