Homeschool Guide: These lesson plans are a guide for parents. Content may contain errors — always cross-reference with official exam board specifications.

lunar phases & eclipses

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4 detailed 50-minute lessons with teaching scripts, worked examples, parent guides, and assessment criteria.

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Lesson Overview

Total Lessons: 4
Tier: Foundation and Higher
Duration: 50 minutes per lesson (200 minutes total)
Exam Boards: AQA, Edexcel, OCR, Eduqas, CCEA

Learning Objectives

Prerequisites

Materials & Equipment

Lesson 1: Introduction: lunar phases & eclipses

Duration: 50 minutes

Starter Activity (5 minutes)

Quick Recall

Write down everything you already know about lunar phases & eclipses. Then check against the key terms: key terms from lunar phases & eclipses. Use a mini-whiteboard or paper.

Main Content (35 minutes)

Parent/Teacher Guide:
Before lesson: Read the script below. Pre-teach key vocab: key terms from lunar phases & eclipses.
If stuck: Re-read the revision notes (link above), then break the content into smaller steps.
Extension: See the Stretch & Challenge ideas in Lesson 4.
Teaching Script (35 mins):
Mins 0-5 - Hook: "Today: lunar phases & eclipses. By the end you will be able to answer exam questions on it unaided. It connects to the rest of Astronomy because the ideas here recur across the spec."
Mins 5-20 - Direct Instruction: Work through the core ideas below one at a time; after each, ask your student to explain it back in their own words.
Mins 20-30 - Guided Practice: Model the worked example together, then let your student attempt the first practice question with guidance.
Mins 30-35 - Independent Practice: 2-3 practice questions from Lesson 3 below, with immediate feedback.
First Look

Start with the revision notes summary, then attempt: explain the key ideas of lunar phases & eclipses

Plenary (5 minutes)

Check Out

Your student states one thing they learned and one question they still have about lunar phases & eclipses.

Lesson 2: Core Concepts: lunar phases & eclipses

Duration: 50 minutes

Starter Activity (5 minutes)

Review Previous Lesson

Quick recap: write 3 key points from Lesson 1 on lunar phases & eclipses. Check them against the notes below.

Main Content (35 minutes)

Key Fact: The Moon orbits the Earth every 27.3 days (sidereal period), but the lunar phase cycle (synodic period) is 29.5 days because the Earth-Moon system also orbits the Sun.
Key Fact: The phases in order: new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent, new moon.
Key Fact: Moon phases are caused by the changing angle between the Earth, Moon, and Sun, which determines how much of the Moon's illuminated hemisphere we see from Earth.
Key Fact: The Moon always shows the same face to Earth (tidal locking / synchronous rotation): its rotation period equals its orbital period.
Key Fact: A solar eclipse occurs when the Moon passes directly between the Sun and Earth, casting a shadow on Earth. The Moon's disc covers the Sun.
Key Fact: A lunar eclipse occurs when the Earth passes between the Sun and Moon, casting its shadow on the Moon. The Moon often appears red due to refracted sunlight through Earth's atmosphere.

Practice (10 minutes)

Q: explain the key ideas of lunar phases & eclipses

Answer:

Plenary (5 minutes)

Explain Back

Your student teaches the key points back to you without looking. Fill any gaps immediately.

Lesson 3: Application: lunar phases & eclipses

Duration: 50 minutes

Starter Activity (5 minutes)

Quick Recall

Recall the key terms: key terms from lunar phases & eclipses. Define each in one sentence.

Main Content (35 minutes)

Parent/Teacher Guide: Let your student attempt each question alone first, then compare with the model answer. Award method marks for correct working even if the final answer is wrong.

Work through the practice questions on the revision notes page for this topic.

Plenary (5 minutes)

Error Review

Review any questions answered incorrectly. Identify whether the error was knowledge, method, or reading the question.

Lesson 4: Exam Practice: lunar phases & eclipses

Duration: 50 minutes

Starter Activity (5 minutes)

Command Words

Review what these command words require: state (one point), describe (say what happens), explain (say why), compare (both sides), evaluate (judgement).

Main Content (35 minutes)

Extended Answer

Extended question: Full-Mark Response Explain why lunar phases occur and why eclipses do not happen every month. Describe the conditions for a total solar eclipse. (8 marks) <div class="

Lunar phases occur because the Moon reflects sunlight, and as it orbits Earth every 29.5 days (synodic period), the angle between the Earth, Moon, and Sun changes, altering how much of the Moon's illuminated hemisphere is visible from Earth. At new moon, the Moon is between Earth and Sun, so its lit side faces away from us. At full moon, Earth is between the Sun and Moon, so we see the fully lit side. At first and last quarter, we see half the lit side. Eclipses do not occur every month because the Moon's orbit is tilted about 5° to the ecliptic plane. At most new moons, the Moon passes above or below the Sun; at most full moons, it passes above or below Earth's shadow. Eclipses only occur when the Moon is near a node (where its orbit crosses the ecliptic) at the same time as new or full moon — these are eclipse seasons, occurring roughly every 6 months. For a total solar eclipse, three conditions must be met: the Moon must be at new moon phase, it must be near a node (crossing the ecliptic), and it must be close enough in its orbit (near perigee) that its apparent size matches or exceeds the Sun's. When all three conditions align, the Moon's umbra sweeps across Earth in a narrow p

Exam Tips: Learn the 8 phases in order — drawing a diagram with the Sun, Earth, and Moon positions for each phase is the best way to remember. | The 5° orbital tilt is the key to explaining why eclipses don't happen monthly — always mention this. | For lunar eclipse questions, explain the red colour via atmospheric refraction/scattering of red light. | Know the difference between sidereal period (relative to stars) and synodic period (relative to Sun) and WHY they differ.
Common Errors: ✗ The Moon produces its own light. ✓ The Moon reflects sunlight. The 'phases' are simply the changing portion of the Moon's sunlit hemisphere visible from Earth as the Moon orbits. ✗ The dark side of the Moon is always dark. ✓ The 'dark side' (far side) receives just as much sunlight as the near side — it is simply the side we never see from Earth due to tidal locking. Both sides experience day and night. ✗ Eclipses happen every new and full moon. ✓ Eclipses only occur when the Moon is near a node (where its orbit crosses the ecliptic) at new or full moon. The Moon's 5° orbital tilt means it usually misses alignment. ✗ A lunar eclipse and a solar eclipse are the same thing. ✓ A solar eclipse
Stretch & Challenge (Grade 8-9):
  • Synoptic links: explain how lunar phases &amp; eclipses connects to another Astronomy topic you have studied
  • Real-world: research one real-world use or example of lunar phases &amp; eclipses
  • Critical: "What are the limitations of the models used in lunar phases &amp; eclipses?"

Plenary (5 minutes)

Assessment Criteria
  • Got it: Confident explanation + correct worked examples
  • Getting there: Main points OK, needs support with detail
  • Not yet: Confused on key concepts - re-run Lesson 2

Homework & Consolidation

Recommended Resources

🎓 Smart Lesson (Guided)