

hen you look up into the night sky, the stars look like tiny points of light. But stars are not tiny - they're huge, burning balls of gas, like our Sun. They just look small because they are so far away.
The stars may all look the same distance away, as if they were pasted on the wall of a giant dome. But, that's an illusion too. Some stars are billions of miles farther away than others.


From Earth, it looks like a connect-the-dots picture on a piece of paper. But if you saw the Big Dipper from a different angle, it would not look flat at all. The stars in the Big Dipper are actually nowhere near each other. Some are seven times farther away than others! If you flew out in a spaceship and looked at the Big Dipper from the side, it wouldn't look like a dipper anymore. To find out what you'd see . . .
To see what the Big Dipper would look like from outer space, make a mobile!
What You Need:
- a black crayon or marker
- an 8 1/2 x 11 inch piece of rigid cardboard or foam core board
- black thread
- aluminum foil, cut into 7 six-inch squares
- a pen or pencil to poke a hole in the cardboard
- tape
- ruler
Chart of Stars in the Big Dipper
# |
Star Name |
Distance from Earth in Light Years |
String Length |
1 | Alkaid | 104 | 4 ¾ inches |
2 | Mizar | 86 | 9 inches |
3 | Alioth | 83 | 9 ¾ inches |
4 | Megrez | 81 | 10 ¼ inches |
5 | Phecda | 83 | 9 ¾ inches |
6 | Merak | 80 | 10 ½ inches |
7 | Dubhe | 123 | 0 inches |

Steps:
1. Print a copy of the Big Dipper Map. Color in the background to look like space, and glue or tape the whole page to the cardboard or foam core board.

2. Poke holes through the cardboard where the "stars" appear on the paper.

3. Cut seven pieces of thread about two feet long.
4. Tape the end of one piece of string to a six-inch square of foil. Crumple the foil into a ball around the string. Make the foil ball as tight as you can. Repeat this six times until you have seven foil ball stars on strings.




5. Poke the free end of one thread through the hole for Star #1 (the first star on the end of the handle). Now find Star #1 on the chart. This star is named Alkaid. In the right-hand column of the chart, you'll see that Alkaid gets a string 4 ¾ inches long.

Pull the thread through the hole until the foil ball is 4 ¾ inches from the board.

Tape the thread in place on the back side of the board.
6. Repeat for all seven threads. Be careful not to let the strings get tangled together as you work. For star #7, pull the string up until the ball hits the board and tape the string down in back.

7. To hang your mobile, poke four new holes through the cardboard, each about an inch in from the four corners. Now cut two more pieces of string, each about two feet long. Pull one piece of thread down through one corner hole and then pull it up through the nearest corner hole. Tie the two ends together, then repeat for the other two holes. Tie the two loops together so the board hangs flat.


8. Hang your mobile from a nail in a doorway, or tape it to the ceiling. Now stand under your mobile and look up. What do you see?

9. Now look at your mobile from the side. That's what the Big Dipper looks like from space - and you didn't have to spend a billion dollars on a spaceship!