You will learn
- Name inner planets.
- Compare features.
- Explain Venus’s heat.
- Explain why Earth supports life.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Inner planets are small and rocky.
- Mercury has little air and many craters.
- Venus is hottest because of the greenhouse effect.
- Earth has liquid water and breathable air.
Words to know
a rocky planet
the layer of gases around a planet
trapping of heat by gases
a bowl-shaped hole from an impact
1. Discover: The four neighbours
Esi compares photos: grey, cratered Mercury, cloudy yellow Venus, blue-green Earth and red dusty Mars. “Only Earth has liquid water and life that we know of,” she says.
Think: What makes Earth special?
2. Understand: Inner planets
Idea 1: Four rocky worlds
Terrestrial planets have solid surfaces. Mercury has almost no air and many craters. Venus has thick carbon dioxide air. Earth has oceans. Mars is cold and dusty.
Idea 2: Venus
Venus’s thick atmosphere traps heat in a strong greenhouse effect, making it about 465 °C, hotter than Mercury.
Idea 3: Earth and Mars
Earth is in the right zone for liquid water, has a protective atmosphere and magnetic field. Mars once had water and is being explored by rovers.
3. Worked examples
Example 1 (I show you): Name
Red planet.
- Mars.
- Dust.
- Rovers.
Answer: Mars.
Example 2 (We do it together): Explain
Venus heat.
- Thick air.
- Traps heat.
- 465 °C.
Answer: Greenhouse effect.
Example 3 (You try): Explain
Earth.
Show the steps and answer
- Water.
- Air.
- Right distance.
Answer: Liquid water and air.
Did you know?
A day on Venus is longer than its year because it spins very slowly.
Why this matters
Comparing worlds helps us look after Earth.
4. Explore: Planet compare
Fill a table comparing the four inner planets on size, temperature, atmosphere and surface features.
- Collect facts.
- Fill the table.
- Rank by temperature.
- Explain the odd one.
Think about it: what did you notice?
What did you notice? Venus was hotter than Mercury despite being farther.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- A ___ planet is rocky.
- An ___ is the layer of gases.
- The ___ effect traps heat.
- A ___ is a bowl-shaped hole.
Guided practice
Question 1. Name inner planets.
Mercury, Venus, Earth, Mars.
Question 2. Which is hottest?
Venus.
Question 3. Which has craters?
Mercury.
Independent practice
Level 1: Start
- Name inner planets.
- Which is hottest?
- Which has craters?
- Which has oceans?
- Which is red?
Level 2: Grow
- Why Venus hot?
- Why Earth lives?
- Why Mars cold?
Level 3: Stretch
- Fill the table.
- Rank.
- Explain.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain why Venus is hotter than Mercury.
Show a sample answer
Use atmosphere.
Another one. Tell a family member one thing from this lesson. Use the words you learned.
Show a sample answer
A clear sentence that uses at least one word from Words to know.
7. Common mistakes
Fix: Venus.
Fix: Not now.
8. Lesson summary and revision card
- I can name inner planets.
- I can compare features.
- I can explain Venus’s heat.
- I can explain why Earth supports life.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Inner planets are small and rocky.
- Mercury has little air and many craters.
- Venus is hottest because of the greenhouse effect.
- Earth has liquid water and breathable air.
11. Next lesson
Next lesson: Outer planets. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Name the four inner planets. [4 marks]
- Explain Venus’s heat. [3 marks]
- Explain why Earth supports life. [1 mark]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- Thick air [1]; greenhouse [1]; hotter than Mercury [1]
- Water or air
- Any [1]; reason [1]
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- Name inner planets.
- Which is hottest?
- Which has craters?
- Which has oceans?
- Which is red?
- Why Venus hot?
- Why Earth lives?
- Why Mars cold?
- Fill the table.
- Rank.
Homework
Compare Earth and Mars in a table.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. Name inner planets. | Mercury, Venus, Earth, Mars. | 1 |
| 2. Which is hottest? | Venus. | 1 |
| 3. Which has craters? | Mercury. | 1 |
| 4. Which has oceans? | Earth. | 1 |
| 5. Which is red? | Mars. | 1 |
| 6. Why Venus hot? | Greenhouse. | 1 |
| 7. Why Earth lives? | Water. | 1 |
| 8. Why Mars cold? | Thin air. | 1 |
| 9. Fill the table. | Table. | 1 |
| 10. Rank. | Chart. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Mercury, Venus, Earth, Mars.; 2 Venus.; 3 Mercury.; 4 Earth.; 5 Mars.. Level 2: 1 Greenhouse.; 2 Water.; 3 Thin air.. Level 3: 1 Table.; 2 Chart.; 3 Sentence..
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Name inner planets | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Compare features | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Explain Venus’s heat | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Explain why Earth supports life | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: “Mercury is hottest.” Venus.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Compare inner planets.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child compares rocky planets. You do not need to be an expert to help.
- Watch a Mars rover video.
- Ask “Could we live there?”
- Safe screens.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: name inner planets; compare features; explain Venus’s heat; explain why Earth supports life.
Prerequisite knowledge. Grade 4 ideas: the Earth, Sun and Moon, day and night, shadows and the seasons.
Materials. Table, pencils. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Print facts.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Show Earth and Mars pictures and ask, “What is different?”
Explanation (10 min). Teach inner planets.
Guided activity (10 min). Learners compare.
Independent activity (10 min). Learners explain.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Which is hottest? Why?
Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. “Mercury is hottest.” Venus.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Compare inner planets. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Research used to shape this lesson. Courseversity Science curriculum, Grade 5 Unit 9, topic 3; Next Generation Science Standards, Earth’s place in the universe; Cambridge Primary Science Stage 5, Earth and space; IB Primary Years Programme, where we are in place and time. These sources informed the lesson.