| A | B |
|---|
| How long does it take for light to travel from the sun to the Earth? | 8 minutes |
| What do astronomers use to measure the distances between stars? | light years |
| What is a light year? | the distance light travels in one year |
| What is the speed of light in kilometers? | 300,000 kilometers per second |
| How far does light travel in one year in kilometers? | 9.5 trillion kilometers |
| What do astronomers use to measure distances to nearby stars? | parallax |
| What is parallax? | The apparent change in position of an object when seen from different positions |
| Astronomers can use parallax to measrue distances up to | a few hundred light-years |
| Example of parallax | When you look at your thumb with one eye, and then the other, the thumb seems to change positions. |
| How do astonomers define universe? | All of space and everything in it. |
| What is used to describe sizes and distances in the universe? | scientific notation |
| What is scientific notation? | a mathematical method using powers of ten. Also, a shorthand method of writing incredibly large and incredibly small numbers. |
| Write the number in scientific notation: 1300 | 1.3 x 10 to the 3rd power |
| Write in scientific notation: 3230 | 3.23 X 10 to the 3rd power |
| Write in scientific notation: 15200000000 | 1.52 x 10 to the 10th power |
| 2500000000000000000000000000 | 2.5 x 10 to the 27th power |
| Optional: Write in Scientific Notation: .00000000001 | 1 x 10 to the -11th power |
