1. Hubble’s Observations - Edwin Hubble, in the late 1920's, discovered that all galaxies are moving away from each other as he observed the red shift in their spectra - he observed that the galaxies that were the furthest from the Earth were moving away from it the fastest - Hubble’s findings showed that the universe was expanding

2. The Big Bang Theory - states that billions of years ago, all the matter and energy in the universe was compressed into an extremely small volume - scientists believe that the Big Bang occurred about 14 billion years ago sending matter and energy outward in all directions - over time, the matter eventually began to clump together forming galaxies - the universe is still expanding today

3. Cosmic Background Radiation - low levels of energy distributed evenly throughout the universe - discovered in 1965 using radio telescopes - this formed shortly after the Big Bang as the universe would have been very hot

4. - over the last 14 billion years the universe has had time to cool off and today is measured at -270 C, three degrees above absolute zero which is the coldest temperature possible - also known as 0 Kelvin - ripples found in the cosmic background radiation at different areas of the universe may represent areas where galaxies were first formed

5. - through studying these ripples scientists have discovered that the matter which makes up stars, planets, and even humans accounts for only 4% of the total matter found in the universe - another 23% of the matter was found to be Dark Matter, matter that does not give off light, but does have gravity

6. - the remaining 73% of the matter which makes up the universe was found to be Dark Energy - scientists believe that dark energy opposes gravity and is possibly responsible for pushing the galaxies in the universe further and faster apart than first thought possible ***