Solar system
The Solar System is the system in space consisting of Sol, our sun, and those bodies under its gravitational control. About 99.8% of the mass is in Sol.
Components
[edit | edit source]Star
[edit | edit source]Planets
[edit | edit source]Moons
[edit | edit source]Six of the eight planets have one or more moons. Planet Earth has one moon, Luna. Jupiter and Saturn each have over one hundred moons, including original moons that formed around the same time the planet formed, and are in more of less circular orbits, above the planet's equators, and a cloud of captured asteroids. Charon, the largest moon of the minor planet Pluto, is unusual because it mass is within an order of magnitude the mass of its primary, Pluto. The Earth-Luna system ranks second, with Luna being 1/81st the massof Planet Earth.
Dwarf Planets
[edit | edit source]Pluto used to be considered the Solar System's ninth planet. But, in the 1990s dozens of objects were discovered, that were close to the size of Pluto, with orbits similar to Pluto's. The discovery of more similar objects was anticipated. Rather than adding dozens of Pluto sized objects to the list of planets, they decided to create a new description, dwarf planet. Dwarf planets had to be large enough that their mass made them more or less spherical, but not large enough to sweep other objects out the region of their orbit. Ceres is the sole object in the asteroid belt that is large enough to be spherical. Its mass is close to the mass of all the other objects in the asteroid belt, put together. All the other dwarf planets are trans-Neptonian objects, in or near the Kuiper belt.
Small objects
[edit | edit source]See also
[edit | edit source]External link
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