Free / Grades 4-6, with reading and decimal support
Solar Model Studio
How can a small display tell the truth about a very large solar system?
6 flexible sessions / about 210 minutes including practice / science, math, reading and art
Suggested rhythm: two sessions a week for three weeks. Week 1: order and groups. Week 2: size and distance. Week 3: critique, revise and explain. Pause or spread sessions out as needed.
Reading, watching and paper activities are free. Parents and instructors can save a collection; scheduling it for a student requires Plus or Lifetime. No upload is required.
Before you begin
Read a simple table, compare decimal numbers and multiply with support. A calculator, pointing or an adult reading aloud is welcome. The linked lessons introduce the eight planets and their broad groups.
A paper investigation, not sky observation. Use the supplied reference numbers indoors. Never look at the Sun through your eyes, a camera, binoculars or a telescope for this project. No outdoor measuring, climbing, electrical equipment, cutting tools or live sky observation is needed. These are rounded reference values, not measurements you made.
Materials
- 6 sheets per learner: Project journal
Print six pages or copy their headings into a notebook.
- 2 sheets per learner: Size and distance displays
Use clean scrap paper. Keep the two models and their different keys separate.
- 1 per learner: Pencil
Point, dictate or use an accessible writing tool.
- 1 shared, optional: Centimeter ruler and calculator
Explain the labeled values without a measured drawing; an adult can handle calculations.
- 1 shared: Browser with audio or transcripts
Read existing transcripts together. Separate worksheet printing is optional.
Choose the support that fits
- More support: order labeled planets first. Calculate together while the learner chooses numbers and explains what the labels mean.
- More challenge: use the supplied Earth diameter and Sun distance to calculate the Earth-to-Sun gap at the diameter model scale. Explain why the two displays cannot share a single scale.
- Access options: use names, patterns, pointing or dictation. A labeled number table is a valid alternative to drawing exact circles. No upload, recording or public presentation is required.
What good evidence looks like
- Name all eight planets in outward order and identify the Sun as a star.
- Explain that a group label, a diameter and a distance answer different questions.
- Calculate selected model diameters and Sun distances with units and a stated scale.
- Label the displays as separate scales, using visible markers only as symbols where necessary.
- Keep a first explanation, correct an unsupported claim and demonstrate the revised display privately.
These are discussion criteria, not a new automatic score. Existing lesson and worksheet records keep their own subjects. Checking off a planned task does not demonstrate mastery or add a second grade.
Session 1 / about 35 minutes
Order is not a photograph
Goal: Arrange the eight planets and say what an evenly spaced lineup cannot tell us.
Preparation / about 5 minutes of adult support: Have journal 1 ready. Keep your first explanation for the last session. Start with names, not colors or a timed recall test.
Read outward from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. The Sun is a star, so it is not planet number one. An evenly spaced lineup is useful for learning this order. It does not show actual gaps, relative diameters or the planets' locations today. Planet models need labels telling us what they show and what they leave out. A neat row is a filing system, not a solar-system class photo.
Someone points to equal gaps in a lineup and says each journey must be the same length. Ask which information the drawing actually gives, and which information would need another source.
- Eight planets, one useful lineup / about 5 minutes
- Put the Planets in Order / about 10 minutes
- Label the lineup honestly / about 20 minutes
Fun fact: The planets move around the Sun; the familiar straight lineup is a teaching arrangement, not a permanent view in space. Source
S3U / Solar Model Studio / Journal 1 of 6
What does this lineup show?
Use the lesson to complete two groups of four names. Keep a first explanation of what a small solar-system display should show; you will revise it later.
| Outward places | Planet names |
|---|---|
| 1, 2, 3, 4 | |
| 5, 6, 7, 8 | |
| The Sun is a... | |
| One thing an equal-gap lineup cannot tell me |
My first explanation: what should a visitor learn from my display?
Why is a row of eight equal-size dots not a photograph or a full scale model?
Session 2 / about 35 minutes
A family name is not a ruler
Goal: Use the three planet groups without treating every member as identical.
Preparation / about 5 minutes of adult support: Have journal 2 ready. Compare group names and properties before using numerical measurements. Keep Earth and Neptune labels available.
Mercury, Venus, Earth and Mars are terrestrial, or rocky, planets. Jupiter and Saturn are gas giants. Uranus and Neptune are ice giants; that name does not mean a solid skating rink. A classification table puts related objects together. It does not measure how wide each object is or how far it is from the Sun. Two objects can share a group while differing in size. Use a diameter, the distance across a planet through its center, when comparing widths.
Ask whether being in the same group makes Earth and Mars the same size. Then ask why a diameter comparison would still not tell us the distance between those planets.
- Planet families: compare, then classify / about 5 minutes
- Compare Planet Families / about 10 minutes
- Choose the right comparison / about 20 minutes
Fun fact: Our four outer planets form two broad groups: Jupiter and Saturn are gas giants, while Uranus and Neptune are ice giants. Source
S3U / Solar Model Studio / Journal 2 of 6
Groups and measurements
These four planets will be the selected sample in our two numerical models. The full outward lineup still has eight planets. Do not treat this sample as the whole solar system.
| Selected planet | Broad group |
|---|---|
| Earth | |
| Mars | |
| Jupiter | |
| Neptune |
Which measurement would let me compare the widths of Earth and Mars?
Give one question that a group label alone cannot answer. What evidence would I need?
Session 3 / about 35 minutes
Shrink widths with one rule
Goal: Use one multiplier to make consistent model diameters for the selected planets.
Preparation / about 7 minutes of adult support: Have journal 3, one display sheet and an optional ruler/calculator ready. Keep the sheet for session 6. The labeled arithmetic matters more than drawing precision.
A size model uses the same rule for every diameter. An Earth-diameter multiple tells how many Earth widths fit across a planet, not how many Earth volumes fit inside it. For a worked example, Mercury is about 0.38 Earth diameters: if model Earth is 2 cm wide, model Mercury is 0.38 x 2 = 0.76 cm wide. Use a different Earth size in the journal. Label the scale and selected planets. The space between your circles is just layout space, not a distance model.
Ask what would go wrong if Earth used a 0.5 cm unit but Jupiter used a 1 cm unit. Could a beautifully drawn model still compare the sizes incorrectly?
- Calculate model diameters / about 15 minutes
- Draw or label the size display / about 15 minutes
- Check what diameter means / about 5 minutes
Fun fact: Jupiter's listed diameter is about eleven Earth diameters; that width comparison is not a count of Earth-sized volumes. Source
S3U / Solar Model Studio / Journal 3 of 6
One diameter scale
Model Earth diameter = 0.5 cm. Rounded diameter multiples from NASA/JPL reference diameters: Earth 1.00, Mars 0.53, Jupiter 11.21, Neptune 3.88. Multiply each by 0.5 cm. These are widths, not volumes.
| Planet / Earth-diameter multiple | Model diameter (cm) |
|---|---|
| Earth / 1.00 | |
| Mars / 0.53 | |
| Jupiter / 11.21 | |
| Neptune / 3.88 |
Show one multiplication. What stays the same for every selected planet?
Write the label that stops a visitor treating your circle spacing as real Sun distances.
Session 4 / about 35 minutes
Give empty space its own scale
Goal: Plot selected reference distances from one Sun marker, not from the previous planet.
Preparation / about 7 minutes of adult support: Have journal 4 and the second display sheet ready. Use a separate distance key. A labeled table is an alternative to measuring very small marks.
An astronomical unit, or AU, is about the Earth-to-Sun distance: roughly 150 million kilometers. Use the supplied rounded reference distances, not today's positions. A worked example at 1 cm per AU puts Venus at 0.72 cm and Saturn at 9.54 cm from the Sun marker. Measure each from the same zero, not from the previous planet. Our journal uses 0.5 cm per AU for a smaller display. Visible dots are location symbols, not correctly scaled planet diameters.
Ask why Neptune's mark is measured from the Sun rather than from Jupiter. If you draw a dot large enough to see, which warning does its size need?
- Calculate distances from the Sun / about 15 minutes
- Make the distance display / about 15 minutes
- Compare the two different scales / about 5 minutes
Fun fact: The reference table puts Neptune about thirty times as far from the Sun as Earth. That comparison concerns distance, not planet width. Source
S3U / Solar Model Studio / Journal 4 of 6
One Sun zero
Distance display: 0.5 cm represents 1 AU. Rounded reference Sun distances: Earth 1.00 AU, Mars 1.52 AU, Jupiter 5.20 AU, Neptune 30.06 AU. Multiply each by 0.5. Keep these numbers separate from the diameter table.
| Planet / reference Sun distance (AU) | Distance from Sun zero (cm) |
|---|---|
| Earth / 1.00 | |
| Mars / 1.52 | |
| Jupiter / 5.20 | |
| Neptune / 30.06 |
Show one calculation with units. Why must every distance start at the same Sun marker?
Why can I not place the size-display circles on this axis and call both sizes and distances one consistent scale?
Session 5 / about 35 minutes
Catch the model that overpromises
Goal: Check a claim against the right evidence and state what the model does not establish.
Preparation / about 5 minutes of adult support: Bring both display sheets and journals 1-4. Keep all earlier wording; revise labels instead of pretending the first version was perfect.
A display can be useful without showing everything. A problem begins when its caption promises more than it shows. A diameter table cannot establish which planet is farthest away. An equal-gap name row cannot establish equal journeys. On our distance axis, subtracting two positions gives the gap between those model marks; real planets move around the Sun, so it is not their current separation in space. Identify the claim, choose the relevant evidence, then add a limit. A confident caption is not extra evidence.
Read "Jupiter must be farthest because it has the largest diameter." Ask which table would actually answer the distance question, and why the diameter table is the wrong evidence.
- Read three overconfident captions / about 15 minutes
- Compare two marked positions / about 10 minutes
- Revise a misleading label / about 10 minutes
Fun fact: A planet-size picture may accurately compare widths while deliberately changing the gaps so the planets fit on a page. Its caption matters. Source
S3U / Solar Model Studio / Journal 5 of 6
Claim, evidence and limit
Critique each invented caption using your two tables. For the final row, calculate the gap between the Jupiter and Mars marks on our same-line distance display, not their current separation in space.
| Claim or question | Evidence and a correction |
|---|---|
| Largest diameter means farthest from the Sun. | |
| Equal gaps in a name row mean equal journeys. | |
| The dots show today's positions in space. | |
| Jupiter mark minus Mars mark (cm) |
Which caption did I change, and why? Keep the first version alongside the revision.
What can the gap between two model marks tell me? What can it not tell me?
Session 6 / about 35 minutes
Open a tiny museum with honest labels
Goal: Demonstrate two models, explain a revision and name an unanswered question.
Preparation / about 8 minutes of adult support: Bring all six journals and the two retained display sheets. An adult can listen or read; private rehearsal is equally valid. Nobody is monitoring live.
Present the eight-planet order and your two selected four-planet models. Give each model a title, its own scale, units and a limit. Explain one calculation and a real revision to your first explanation. A visitor should be able to tell a size comparison from a distance comparison without guessing from colors. The Sun is the zero marker in the distance display, not a correctly sized drawing of the star. Your tiny museum does not need a tiny gift shop, an upload or an audience online.
Ask a listener, or ask yourself: "What might someone misunderstand without this label?" Then improve one caption without changing the reference values to fit a preferred picture.
- Finish the two-part display / about 15 minutes
- Explain and revise privately / about 15 minutes
- Choose a next space question / about 5 minutes
Fun fact: At a single common scale, even an Earth only 0.5 cm wide would sit roughly 59 meters from the Sun, using the supplied rounded reference numbers. Source
S3U / Solar Model Studio / Journal 6 of 6
My models and their limits
Use the reference numbers, not a claim that you measured planets. Optional challenge: Earth diameter 12,756 km and Earth-to-Sun reference distance 149,600,000 km. At a 0.5 cm Earth diameter, calculate the Sun distance in the same scale, then convert centimeters to meters.
| Final display check | My evidence |
|---|---|
| Eight-planet order and Sun label | |
| Two different scales with units | |
| One calculation and one limitation | |
| First explanation and justified revision |
What changed in my explanation, and what evidence caused that change?
What question can my display not answer? What different observations or information would help?
What changed in your explanation?
Show your evidence, explain one revision, and choose a question to investigate next. You can keep everything on paper.
Optional: record actual offline learning in Learning Records. Keep reported minutes separate from website time. For an assigned pack, use your existing daily tasks; this page does not award additional completion credit.