The Solar System is located in the Milky Way galaxy and consists of the Sun at its center, eight planets including Earth, over 60 moons orbiting various planets, asteroids, comets, and other celestial bodies. The Sun is a hot gas ball and active star that the planets, moons, asteroids, and comets orbit around. Comets are made of ice and rock that release gases and form tails when heated during approaches to the Sun.