In the solar system there is a total of nine planets. There are four inner planets and five outer planets. The nine planets rotate around the sun. They move in paths called orbits. Because Mercury is the closest it takes only 88 days to go around the sun. Because Pluto is the farthest planet it takes 248 years! Mercury is the closest to the sun making it the hottest while Pluto is the farthest making it the coldest planet. Neptune and Pluto are the coldest planets because theyre the farthest ones away form the sun.

          The largest planet is Jupiter. More than 1,000 Earths could fit into it. It contains more than twenty percent of all material in our solar system. Pluto is the farthest planet in our solar system, but comets and asteroids are many miles further making the solar system 280 trillion miles. Their may be many more planets beyond Pluto, but our best telescopes havent spotted them. In 1977 the astronomer Charles Kowal discovered a mysteries object out beyond Saturn. It turned out to be a little world smaller than Earth. It was named Chiron, and just like all major planets it circles the sun so it can technically be called a planet or an asteroid.