Course 244 · Life course 66

Model the Sun, Earth and Moon

A labeled astronomy model explaining day/night, seasons, Moon phases and eclipse geometry with two misconception corrections. Six introductory lessons use supplied practice cases.

Before you start

Use paper or a free text document; every core input is supplied in the lessons.

Scientific Reasoning and Lab Readiness See everything you’ll need

Free download · Original practice data · No external account required. Download the starter pack

What you’ll leave with

A labeled astronomy model explaining day/night, seasons, Moon phases and eclipse geometry with two misconception corrections.

Start course Start without an account. Sign in to save lesson progress across devices.

Your project

Start with the practice files. Build your project one lesson at a time.

Practice files are free without an account. Sign in to save your project record in My Proof: a description, checklist, and optional work link. Keep the original files in your own app or notebook; saving a project record does not upload them.

Get your materialsDownload practice filesSupplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.
Make your projectView the project checklist Work in your own notebook, document, or software. Use the supplied practice examples when you prefer.
Keep a private recordSave a project record Sign in to save a description and checklist, then return to update them.

Course handbook

Know the route before you begin.

Here’s what you’ll need and what you’ll make. You can return to this guide during any lesson.

Who this is for

Learners aged 14+ building subject foundations and practical independence. Adults can use the same supplied cases.

Prepare before lesson one

Use paper or a free text document; every core input is supplied in the lessons.
A basic calculator is optional; show the method, units and checks.
Suggested earlier course: Scientific Reasoning and Lab Readiness

Your final project

Finish with proof you can use.

A labeled astronomy model explaining day/night, seasons, Moon phases and eclipse geometry with two misconception corrections.

Save a project record in My Proof

See project checklist and review criteria

Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.

What to include

Label separate rotation axes and revolution paths.
Trace an equatorial day/night model with its limits.
Explain opposite seasons using fixed-direction axial tilt.
Draw three lunar phase geometries.
Distinguish aligned eclipses from off-shadow phases.
Apply the supplied distance scale, correct two misconceptions and complete changed cases.

Review and revise

Use these criteria to check your work and choose what to improve.

Method: applies the course-specific rules to the supplied cases with visible intermediate work.
Accuracy: results agree with the stated facts, units, boundaries and independent checks.
Reasoning: explains why the result follows and identifies a limitation or unresolved question.
Transfer: completes changed cases and revises the final project when a relevant assumption changes.

Three ideas to help you along the way

Three useful ideas

The rules behind the steps.

Check the specific conditions

Rotation is turning about an axis; revolution is motion around another body. Earth rotates while orbiting the Sun, and the Moon both rotates and orbits Earth. Different motions produce different observations and time scales. For the simple daily sketch use a rounded 24-hour cycle; an exact solar day and sidereal rotation use different reference definitions.

Follow the supplied evidence

At any ordinary moment, the Sun illuminates approximately one hemisphere of Earth. Rotation moves most surface locations between illuminated and dark regions. Day/night length depends on latitude and season; a half-lit globe does not guarantee every location has exactly 12 hours of each every day.

Keep the limits visible

A solar eclipse requires Moon-between-Sun-and-Earth geometry with its shadow reaching the observer; a lunar eclipse requires Earth-between-Sun-and-Moon geometry with the Moon entering Earth’s shadow. The Moon’s orbit is tilted, so new and full phases do not guarantee eclipses. This is desk geometry only; never look at the Sun as a course task.

What do these words mean?

Key words

Key terms worth knowing.

Rotation: Turning about an axis.
Revolution: Orbital motion around another body.
Axial tilt: Orientation of a rotation axis relative to an orbital plane.
Phase: Visible fraction of the illuminated lunar hemisphere from Earth.
Eclipse: An aligned shadow or obscuration event in the supplied geometry.
Scale: A declared relation between represented and model actual distances.

Your route

6 lessons.
One useful project.

Work in order the first time. Each lesson makes something the next lesson can use.

Use the tools

Tools to help you practice.

See all tools

ZIP · practice files

Model the Sun, Earth and Moon practice files

Supplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.

Text worksheet

Your course project worksheet

A downloadable text worksheet with each lesson’s working output, space for your answers, and the shared final-project checklist. Save your own copy.

Source transparency

Sources and further study.

Explore the references behind the lessons and take your learning further. Source notes explain access and reuse.

OpenStax: rotating Earth and apparent sky

Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.