planet earth is part of a system of planets and their moons, as well as numerous asteroids and comets which orbit around a huge star we call the Sun. The Sun itself consists of gas. Nuclear reactions inside its core produce the heat and light that make life on the Earth possible. The Earth is the third of four small terrestrial (Earth like) planets that orbit close to the Earth. Further out in our Solar System are four huge gas planets, while distant Pluto, the smallest planet, is made from rock and ice. our Earth is one of the ten planets that orbit the Sun- a huge, burning-hot star in the center of our Solar System. The Solar System and all the stars in the sky are part of our galaxy - the Milky Way , which contains as many as 200 billions stars. Beyond our galaxy are millions more galaxies. They all add together to make up the Universe