Our sun is a medium sized star. It is the center of our solar system. The sun's gravity holds everything in the solar system together. Our solar system has planets, moons, dwarf planets, asteroids, meteors and comets. Everything orbits or moves around the sun.
There are eight planets that orbit the sun. Starting closest to the sun, the order of the planets is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Mercury, Venus, Earth and Mars are called the inner planets. The four inner planets are made mostly of rock. They are all small planets.
Jupiter, Saturn, Uranus and Neptune make up the outer planets. The four outer planets are made mostly of gas. They are giant-sized planets.
Our solar system has only one star or sun. It is part of a huge galaxy called the Milky Way. Scientists think there are 200,000,000,000 (two hundred billion) stars in the Milky Way!
