Introduction

Since mankind arose, people have looked to the stars, believing them to be Gods. Some called them the 'Wanderers', and invested a complex mythology in them. Many cultures worshipped them through song, praise, prayer and even ritual sacrifice. For thousands of years people thought the planets, moons and Sun revolved around the Earth, and that the Earth was the center of the universe. When telescopes were invented in the seventeenth century, people began to think that the Earth wasn't the center of the universe, and that the planets did not revolve around the Earth, but rather the Sun. This concept was called heliocentrism. People started thinking of the planets as worlds very much like our own, and not the mythological Gods people thought they were. People started to think that other civilisations existed on other planets. As telescopes were improved, more planets were found. Uranus, Neptune and Pluto. There may even be other planets beyond Pluto, but only time will solve the answer to that question.

Our Solar System was created when a nebula, made up of mostly hydrogen, gradually collapsed and formed a spinning protostar. Gravitational contraction heated the protostar and a nuclear fission reaction was sparked in the hot, dense gas that condenced at its center. Our Sun was born. The planets were formed from the remaining disc of material still swirling around our new-born Sun. The largest four of our planets were composed of mainly hydrogen as well as helium. They and the Sun are relics of protostellar material that existed 4.6 billion years ago. The impurities went to form the terrestrial planets.

Note: The Solar System Quiz has recently been updated to version 3.0.0