The document describes the 8 planets in our solar system: Mercury is the closest planet to the sun and has no moons. Venus is the second planet and is most similar to Earth. Earth is our planet and has day/night cycles from its rotation and orbits the sun in 365 days with 1 moon. Mars is the red planet with 2 moons. Jupiter is the biggest planet and is made of gas with many moons. Saturn has rings composed of rocks and many moons. Uranus is the third biggest planet with 27 moons and rotates on its axis every 18 hours. Neptune is the coldest planet with 13 moons and rotates every 16 hours.