Space Travelers

Vocabulary: Soil, Soil Formation, Weathering (breakdown), Decomposition, Microorganisms

Grade Levels: K-2nd

Science Framework   Spanish Lesson Plan   Lesson Video    Lesson Inspiration

Lesson Overview:  

In this lesson, students will work in small groups as space travelers to decipher the composition of soil.  After dissecting soil to identify ingredients, they will attempt to manufacture soil.  Students will then learn about the important role weathering and decomposition play in soil formation. They will also discuss how people and healthy soil are codependent.

NGSS Performance Expectations by Grade Level

Standards below were reviewed and updated (July 2026) against the current Next Generation Science Standards.

• Kindergarten | K-LS1-1: Use observations to describe patterns of what plants and animals (including humans) need to survive.
  In this lesson: Students learn that plants need healthy soil to grow, and that soil itself is full of living decomposers.
• 1st Grade | 1-LS1-1: Use materials to design a solution to a human problem by mimicking how plants and/or animals use their external parts to help them survive, grow, and meet their needs.
  In this lesson: Decomposers like worms use their body parts to break down leaves and sticks into soil.
• 2nd Grade | 2-PS1-1: Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties.
  In this lesson: Students dissect soil and classify its ingredients, sand, rock bits, roots, and decomposed matter.

Essential Questions

Each question pairs a Crosscutting Concept (CCC) with a Science & Engineering Practice (SEP).

• What do you think soil is made from?
• How does a big rock turn into lots of little rocks that make sand?
• Can humans turn a big rock into sand? Would it be easier for us to do, or easier for nature? What would take longer?

Vocabulary

Soil- A mixture of elements and organic material that covers earth’s surface and it very important when growing food

Soil Formation- The process by which soil is made from weathering and breaking down of rocks and organic material

Weathering (breakdown)- The process where rock is broken into smaller and smaller pieces by wind, water, or ice

Decomposition- When something breaks down into smaller parts, usually with the help of microorganisms

Microorganisms- Living things that are so tiny we cannot see them with our eyes, but they are there!

Materials:

• Trowels at least 10 total
• Newspaper, paper bags, or butcher paper for students to look at soil on
• 5-6 Clipboards
• 5-6 Pieces of paper for students groups to take notes
• Photos of abstract decomposers
• Photos of decomposers
• Magnifying glasses (optional)
• Bugs, Humans, and Soil Series Garden Journal (optional)

Prep:

Make sure there is good material in the garden for making “soil.” If needed you can bring in some easily broken sandstone, dirt clods, and other materials for students to break up. Have newspaper or paper bags stacked and ready for each group to have one

Optional: Open up your vermicompost bin for students to explore during the lesson.

Activity Procedure:

Engage:

Gather students into the seating area of your garden.  Ask students to close their eyes.  Read the following in your most alien voice:

“Imagine that we are aliens from the planet Zog, journeying to planet Earth on the starship Zogma.  We have been chosen to make an important journey.  The people of Zog want to find out how to grow our own food.  Our mission as scientists is to find this material called “soil”, and learn how we can make it on Zog. This will allow us to learn the secret of this material so we can make soil back on planet Zog.”

Explore: (Allow 15 minutes for this free exploration)

Divide students into groups of three to four and give each team a hand trowel, some newspaper, and a clipboard with paper and pencil to take note of what is in the soil. They can use words or drawings here.  Have students explore soil in different areas of the garden and schoolyard by digging up a trowel-full and placing it on the newspaper.  Have students in each group dissect the soil, identifying each substrate found.  One student in each group can record the soil ingredients.

Explain:

Think, Pair, Shares: What is the soil made of? What parts did you notice in the soil that you saw in the garden?

Sentence Frame: The soil is made of __________.

Soil is made from broken-up bits of rocks and dead plants and animals. Sometimes it has broken shells, and bones in it. What explains how rocks, branches, leaves, sand, and other natural materials develop into the soil? (Cause and Effect; Construct Explanations and Design Solutions). Does anyone have any idea how rocks, plants, and animals get turned into soil? Rocks get broken into tiny pieces from rain, wind, and rivers. When plants and animals die they get broken down when they get chewed up and eaten by tiny bugs we can’t see, like bacteria. These bugs are called decomposers.

Thumbs up/down: Who has heard of the word decomposer before?

A decomposer is any living thing that breaks down non-living things. Mushrooms, worms. and centipedes are all decomposers. Who remembers what our mission from Zog is? That’s right to make soil. Now that you’ve discovered that soil is made from rocks, sticks, and leaves, you can work in groups to try and make your own soil!

Action:

This activity can take less time as the exploration is longer.

1. Review your Garden Agreements
2. Divide students into groups (they can return to the groups from earlier).

1. Alternatively, you can do this as a class altogether. It does not take long to see that we cannot make soil with our hands.

3. Let students collect a few sticks, fallen leaves, and stones from the garden.
4. Using only their hands, have students try to break the materials apart to make soil
5. If you have a newspaper, give students a sheet per group so they can place their finished “soil” onto it.

Reflect:

Have a student from each group share what they created and discovered about soil from the experiment. Was it easy to make soil? Explain that each inch of topsoil requires more than 100 years to form through a process known as weathering and decomposition.  Our hands and tools cannot equal the power of the weather and decomposers!  Also, soil is alive, with more than 100 billion microorganisms living in a pound (0.45 kg) of soil, in addition to the roots, insects, worms, and other living things we can see in the soil.  There is no recipe that could help people to be able to do in a day what nature does in many years. We can be thankful for all the microorganisms and all the years of weathering that have given Earth’s crust so much good soil.

 So was our mission a failure? What would the aliens of Zog need to be able to make soil? (decomposers and lots of time).

Sentence Frame: To make soil we need _____________.

Extension Activities:

• Work on this What’s in Soil coloring page
• If there is time, head out into the garden together to look for worms and other invertebrates; fungus; partially decomposed plant material; and any other evidence of decomposers making soil. Great opportunity to practice using magnifying glasses!
•  Check out the classroom worm bins or construct a classroom worm bin (Follow this lesson plan for guidance:  The Great Worm Tillers)
• Let students pick a decomposer to observe and draw using this worksheet.

Cited Curriculum:

LifeLab - The Growing Classroom: Space Travelers