Along, long time ago, in a galaxy far, far away, there was abig bang! Matter (dust and gas cloud) was sent flying out in all directions. But what caused the huge cosmic explosion? Astronomers(scientist who study the stars and galaxies) believe that all the matter in the universe was squeezed very tightly into firebll. The temperature of this fireball was so high that it exploded. And that is why this huge explosion is known as the big bang!
Can you guess what happened to the matter that was sent flying after cosmic explosion? It cooled and became stars and galaxies. One of these galaxies became a group of planets known as the solr system
