Solar System
The solar system is the sun and all the objects in orbit around the sun.[1] Objects orbiting the sun include planets, moons, asteroids, and comets.
Planets
A planet is defined as an object that orbits the sun, is massive enough that its own gravity pulls it into a nearly round shape, and is dominant enough to clear away objects in its neighborhood. [2] There are 8 planets in the solar system. They are, in order of increasing distance from the sun:[3]
Dwarf Planets
A dwarf planet is an object that orbits the sun and has a round shape. [4] The crucial difference between a planet and a dwarf planet is that a dwarf planet is not large enough to clear the neighborhood of its orbit. The only dwarf planet in the solar system is Pluto
Asteroids
There are two asteroid belts in the solar system, the one between the orbits of Mars and Jupiter, and the Kuiper belt, which is in Pluto's orbit around the sun.
References
- ↑ Freedman, Kaufmann: Universe, 7th edition
- ↑ http://www.nasa.gov/vision/universe/solarsystem/planetsf-20060824.html
- ↑ The third grade
- ↑ http://www.nasa.gov/vision/universe/solarsystem/planetsf-20060824.html