This document discusses our solar system and celestial bodies. It explains that our solar system consists of the sun, eight planets, moons, asteroids and comets. Jupiter is the largest planet and Mercury the smallest. The document defines celestial bodies as objects that shine in the night sky, including the sun, moon and stars. Stars are defined as celestial bodies that produce their own heat and light, with the sun being the largest star in our solar system. It describes how ancient people used constellations like the Big Bear and Little Bear to determine directions at night and find the pole star.