The Solar System Solar System Formation The Inner Planets The Outer Planets Inner and Outer Planets Planets Table 20 Largest Objects
The Solar System is the Sun and the many objects that orbit it. These objects include eight planets, at least five dwarf planets and countless asteroids, meteoroids and comets. Orbiting some of the planets and dwarf planets are over 160 moons. The Sun keeps its surrounding objects in its orbit by its pull of gravity which has an influence for many many millions of miles. The Sun is a star like many other stars in space and it is known that other planets exist in orbit around other stars. This means that your Solar System is not the only Solar System in the Universe but it is the only one that we know a great deal about. However, by observing the formation and demise of other stars and their planets, scientists are able to gain knowledge about how your Solar System was formed and how it may eventually end.
The planet you live on is Earth, the largest of four rocky planets. Because they are the closest to the Sun, these rocky planets are also known as the Inner Planets. The other Inner Planets are Mercury, Venus and Mars. Beyond Mars are the Outer Planets, also known as the Gas Giants. These planets are Jupiter, Saturn, Uranus and Neptune. Between the Inner and Outer Planets is a region of asteroids known as the Asteroid Belt. All planets apart from Mercury and Venus have moons orbiting them. Moons are small rocky worlds, some round, some irregularly-shaped, all kept in orbit by the gravitational pulls of their planets, in the same way as the Sun keeps the planets in its orbit. Dwarf planets are small worlds which orbit the Sun. Ceres orbits the Sun in the Asteroid Belt and Pluto, Huamea, Makemake and Eris orbit beyond Neptune.