Education and
Public Engagement
at the Lunar and Planetary Institute
To the Moon and Beyond From Apollo to the Future

The Scoop on Moon Dirt

modified from "Regolith Formation," an activity in Exploring the Moon, A Teacher's Guide with Activities for Earth and Space Sciences, NASA Educational Product EG-1997-10-116 – HQ by J. Taylor and L. Martel.


Children ages 8 to 11 compare how soil forms on Earth and the Moon,exploring how water, wind, and impactors help to make soil.

What's the Point?


For the group:

For each team of three to four children:

For the facilitator:


A Word on Words . . .

The term "soil" is being used in this activity because children are familiar with "soil." "Regolith" is a more appropriate term and is introduced.

Soil: the unconsolidated (loose) top layer of material on Earth's surface that is made of minerals and, usually, organic matter in which plants grow.

Regolith: a general term for the layer of loose rock material that forms the surface of a planet — including Earth! — and covers the rock. Soil is a type of regolith. Other types of regolith include volcanic ash, materials deposited by a glacier or river, sand dunes, the red rocky surface materials of Mars, and the layer of material on the lunar surface.

Dirt: a term used by small children and gardeners to describe soil; a term used by scientists when they are unimpressed with the qualities of the regolith they are investigating or when they are more interested in the layers of rock beneath the regolith.


1. Invite the children to tell you what they know about dirt or soil.
What is it made of? Where is it found? Are there different types of soils?
Share that the Moon and many planets and asteroids have a special type of soil on their surface, called regolith. Unlike the soil on Earth, the regolith on the Moon doesn’t have any organic materials: no seeds, roots, or bacteria.

Ask the children to share what they know about the Moon. Remind them that the Moon has no water and no atmosphere, in addition to other insights they may share.

2. Invite the children to think about different ways regolith can form.

3. Place the children in  groups. Provide each group with the frozen block of water and sand and ask them to imagine that this is a rock — a sandstone! Have the groups place their "rock" in the dishpan under the faucet and turn the water on at a slow to medium stream. Alternatively, use water poured from a pitcher or bottle.

4. Bring the children back together to discuss what they found.

5. Now invite the children to explore how wind can break down rocks. Provide each group with a piece of dry, brittle bread and ask them to imagine it is a rock.

6. Bring the children back together to discuss what they observed.

What does make regolith — the lunar "soil?" Do the children have any ideas? Show them the image of the Moon. What are the round shapes on the Moon's surface? How do they form?

7. Divide the children back into groups and provide each group with the container of graham crackers and large rock. The graham crackers are the lunar surface, the rock is a large asteroid! Ask the children to drop the asteroid, from about waist high, into the container.

8. Bring the children back together to discuss their observations and thoughts.


Revisit with the children what they have learned.