Hawai'i Space Grant College, Hawai'i Institute of Geophysics and Planetology, Univeristy of Hawai'i, 1996

Regolith Formation
Purpose

To compare and contrast the process of regolith formation on Earth and on the Moon.

Key Words

regolith

meteoritic bombardment

weathering

erosion

Materials

small pan

sand paper, nail file,
or edge of ruler

ice cube with sand inside

tray

fist-size rock

Regolith Formation on Earth

### Procedure A What effect does wind have on regolith formation?

1.
Imagine that the piece of toasted bread is a rock on Earth. Your hand is the wind. The sand paper is wind carrying particles of sand.

2.
Predict the effects of rubbing just your hand and then the sand paper across the taosted bread.

3.
Now try it. Rub your hand across the toasted bread and observe the bread the the pieces which fall from it onto the pan. Observations:

4.
This time, rub the sand paper across the toasted bread and observe the bread and the pieces which fall from it onto the pan. Observations:

5.
How was the effect different?

6.
How is this activity related to processes on Earth?

### Procedure B What effect does falling or fast flowing water have on regolith formation?

1.
Imagine that the ice cube with sand is a rock.

2.
Place this ice cube on a collection tray beneath the water faucet.

3.
Adjust the water flow from the faucet so a medium stream hits the ice cube.

4.
Observe what happens to the ice cube and the remaining particles.

5.
What hapened to the rock (ice cube)?

6.
Describe the particles which remain.

7.
How does water contribute to regolith formation on Earth?

Regolith Formation on the Moon

### Procedure C

1.
Do you think regolith on the Moon is formed in the same manner as on Earth? Why or why not?

2.
Now we will investigate the effects of meteoritic bombardment on regolith formation.

In a small pan, place 2 slices of toasted white bread onto 3 slices of toasted golden wheat bread. This represents the Moon's crust.

3.
Drop a rock onto the layers of toasted bread twice. Describe the bread slices and the crumbs.

4.
Drop the rock 20 times onto the layers of toasted bread. Describe the bread slices and the crumbs.

5.
Which crumbs can be seen at the surface? Why?

6.
How does the thickness of the crumb layers compare after 2 hits and after 20 more hits?

7.
How does meteoritic bombardment make regolith on the Moon?

Go to Regolith Formation Teacher pages.