Introduction!!!!!
The solar system still has stuff yet to be discovered. A planet is an object that is round, orbits the sun, and have cleared out the region of the solar system along its orbit. The center of the Solar System is the Sun. Then come the Inner Planets, Mercury, Venus, Earth, and Mars. Followed by the outer planets that include Jupiter, Saturn, Uranus, and Neptune. All of the planets revolve around the sun and it takes different time periods to revolve the sun for different planets. Separating the Inner Planets and Outer Planets is the Asteroid Belt. Asteroids are rocky objects that orbit the sun. The Sun holds the planets in their spots with a force called gravity. Gravity is a force that attracts all objects toward each other. Without gravity the planets would be all over the place. The Solar System is so big scientists can't use kilometers as a measure so they created a new unit for measure called the astronomical unit. An astronomical unit is 150,000,000 kilometers and which is the average distance from Earth and the Sun. The solar system also includes smaller objects that orbit the Sun. Some, called asteroids, are small, mostly rocky bodies. Many asteroids are found in an area between the orbits of Mars and Jupiter. Comets are another large group of Solar System objects. Comets are loose balls of ice and rock that usually have very long, narrow orbits.