Our Solar System has been a home for life on Earth for 4 billion years. The solar system is composed of eight planets- no Pluto, get over it- and a star, our Sun. We live on the 3rd Planet from the Sun, Earth. However, each planet has its own unique identity that we'll later explore. As we'll learn later, the solar system is littered with extra-terrestrial objects such as comets, meteors, asteroids and dwarf planets.