The sun orbits the earth and it’s the only star in our solar system. Stars are like a ball of gas held by its own gravity. A space probe is a piece of technology that explores and collects information from our planets. There are more stars in the universe than grains of sand on all beaches. The earths atmosphere is made up of several layers. Space exploration is an ongoing discovery and exploration of structures in space. Many solar systems together form a galaxy. Every planet rotates on its own axis having differents lengths of day and year. Constellations have been an important part of human society. Neil Armstrong was an astronaut and the first person to land on the moon.