2. HISTORY OF THE UNIVERSE Andromeda Galaxy is 2,000,000 light years away. It is the farthest galaxy that we can see. That means that the light traveled for 2,000,000 years before it reached your eye. Astronomers have found galaxies that are billions of light years away. That means that the universe is billions of years old. We can tell how old galaxies are by how they are moving away from us. (most are moving away.)

5. Hubble discovered that the farther away from us, the faster it is moving. The Hubble telescope was named after him. If we think of raisin bread dough rising we can see how the universe is expanding as the stars move away from each other. If we played the time tape in reverse all the stars would come back and come together at one point. The best theory states that all the matter in the universe was in one dense hot spot and then exploded and is still moving away. That is called the Big Bang Theory.

7. According to the Big Bang Theory the universe formed in an enormous explosion about 10 to 15 billion years ago.

8. Imagine taking a corn kernel and expanding it to the size of the Earth. After the Big Bang some dust and gases formed clouds that collapsed in on themselves and formed stars and solar systems. About 5 billion years ago a cloud of gases and dust, called a nebula, collapsed to form our solar system.

11. As gravity pulled the gases together they became hot enough to allow fusion to take place and our sun was born. Elsewhere smaller spheres formed into our planets. The inner ones lost their gases and became solid. Mercury, Venus, Earth, and Mars The outer retained their gases and became the gas giants. Jupiter, Saturn, Uranus, and Neptune Beyond the gas giants is an area of ice and other substances. That is where the comets and Pluto were formed.

12. THE FUTURE OF THE UNIVERSE There are two probable theories. The universe may continue to expand and all the stars will burn out. The universe will then become cold and dark. Gravity may begin to pull the universe back in and we will have the reverse of the Big Bang, the Big Crunch. We will have a huge black hole. It all depends on whether there is enough gravity to pull it all back. We will have to wait and see.

13. This engineer is checking data from the Hubble Space Telescope. The telescope can be controlled from this room.