"On the seventh space shuttle flight, astronaut Robert Crippen noticed a pit in the windshield. After landing, the windshield had to be replaced. Using x-rays, scientists figured out that the window was the victim of a paint fleck no bigger than a pencil point."
-Marianne Dyson, Space Station Science
To demonstrate the difference speed can make in terms of impact craters, you can use a penny, a few eggs, a bowl and a ruler (yardstick would be even better, but we don't have one.)
Put the egg in the bowl and place it on a table or on the floor. Hold a penny 4 inches above the egg and drop it. Double the impact by doubling the height, from which you drop the penny (8 inches.)
Keep adding 4 additional inches each time until the penny penetrates the shell.
|It is hard to see in this photo, but the egg began to get dimples and cracks in it when the penny was 16-24 inches away.|
You can continue to experiment. Are the dents or cracks larger as you hold the penny further away from the egg before dropping it?
Now crack another egg and place part of it's shell over another egg. Drop the penny on this combination as you did before. Did this help protect the egg underneath?
The astronaut and physicist Fred Whipple used this concept when he invented the "Whipple Bumper" to protect space stations. It consists of an outer aluminum wall, a layer of material between the walls and then the wall to the space station. The outer wall will take the damage without it affecting the actual wall of the space station.
- Space Station Science, Marianne Dyson