The solar system is filled with planets, comets, and asteroids, and yet the only planet with known life is Earth. You started this module learning about the formation of the Solar System. Sometime around 4.6 billion years ago, a dust cloud in space began to contract. The collapsing of this cloud created the Sun, planets, comets, and everything else in the Solar System. There are the smaller, dense, rocky terrestrial planets that make up the inner Solar System. Traveling further out are the outer planets. You learned that these planets are called gas giants or Jovian planets. These large planets have rings, many moons, and gas filled atmospheres. Last, you investigated the smallest objects in the solar system. Dwarf planets, such as Pluto, are defined by a series of characteristics. Comets are called, "dirty snowballs." Asteroids are located between Mars and Jupiter, and meteors burn up in the atmosphere of planets in a spectacular fashion.
Over time, astronomers have learned a lot about the Solar System. But, the study of the Solar System will not stop now. Exciting missions continue to look for life, take amazing photos, and even land robotics on different planets. Who knows, maybe one day you will be an astronaut who gets to view Earth from space as you travel to another planet!