Quiz

1. What is our place in the universe? We live in the Milky Way galaxy. We are the third planet from the sun.
2. How did we come to be? The matter in our bodies came from the Big Bang, which produced hydrogen and helium
3. How can we know what the universe was like in the past? When we look to great distances we are seeing events that happened long ago because light travels at a finite speed.
4. Can we see the entire universe? No
5. How big is Earth compared to our solar system? The distances between planets are huge compared to their sizes—on a scale of 1-to-10 billion, Earth is the size of a ball point and the Sun is 15 meters away.
6. How far away are the stars? The stars are thousands of km away.
7. How big is the Milky Way Galaxy? It would take more than 3,000 years to count the stars in the Milky Way Galaxy at a rate of one per second, and they are spread across 100,000 light-years
8. How big is the universe? 14 billion light years in radius.
9. How do our lifetimes compare to the age of the universe? On a cosmic calendar that compresses the 
10. history of the Universe into one year, human civilization is just a few seconds old, and a human lifetime is a fraction of  a second
11. How is Earth moving in our solar system? It rotates on its axis once a day and orbit the Sun at a distance of 1 A.U. = 150 million km