The solar system is the sun and the planets going around the sun. There are eight planets in it. In order of distance from the sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Scientists used to consider Pluto the ninth planet in the solar system. But they do not think that way now. Instead, they consider Pluto to be a minor planet. There are many objects like Pluto in the outer solar system. And scientists don't think they are planets. So they don't consider Pluto a planet anymore.