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| | satellite, natural on Encyclopedia.com (Site not responding. Last check: 2007-11-02) |
 | | The most familiar natural satellite is the earth's moon ; thus, satellites of other planets are often referred to as moons. |
 | | Neither of the inferior planets, Mercury or Venus, has a known satellite; all of the superior planets (those whose orbits lie beyond the orbit of the earth) have at least two known satellites (Mars, 2; Jupiter, 63; Saturn, 48; Uranus, 27; Neptune, 13; Pluto, 3). |
 | | A number of satellites, e.g., Phoebe of Saturn, Triton of Neptune, and most of the small outer moons of Jupiter and Uranus, have retrograde motion and may be asteroids that were captured by the planet's gravitation. |
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