1. #4 The galaxy in which Earth is located is the: A. Andromeda B. M87 C. Milky Way D. Magellanic

2. FORMATION OF THE UNIVERSE https://www.brainpop.com/science/space/bigbang/ CHAPTER 15 – 4 Part 1

3. THE BIG BANG THEORY To understand how the universe was formed, scientists study the movement of the galaxies. Careful measurements have shown that most galaxies are moving away from each other.

4. Having discovered that the universe is expanding, scientists have worked backward to see how it was formed. This research showed that all matter was squeezed into a small space.

5. The BIG BANG Theory This theory says that all matter and energy in the universe was compressed into an extremely small volume that exploded and began expanding in all directions.

6. A Tremendous Explosion About 14 billion years ago, all contents of the universe were compressed under high pressure, at high temp., and high density into a very small volume. Then the universe rapidly expanded and cooled.

7. Within the first 3 minutes of this ”big bang,” the initial elements, forces of nature, like gravity, and seeds of galaxy formation were determined.

8. Cosmic Background Radiation The energy from the original explosion was distributed in every direction as the universe expanded. This is called cosmic background radiation.

9. LET’S TRY IT! LAB: The Expanding Universe