Gravity and Earth Cycles

Overview

Students learn how gravity keeps planets and moons moving around the Sun. They find out how Earth's tilt and spinning cause seasons and changes in day and night. They also explore how gravity affects tides and ideas about space travel. Students use simple models and explanations to share what they learn.

Learning intentions

• WALT understand that gravity keeps planets and moons moving around the Sun.
• WALT explain how Earth's tilt and spinning cause seasons and changes in day and night.
• WALT see how Earth's spinning makes day and night.
• WALT learn how gravity affects tides and helps with ideas about space travel.

Success criteria

• I can say why planets and moons stay in orbit and don't float away.
• I can explain how Earth's tilt changes seasons and day length.
• I can describe how Earth's spinning causes day and night.
• I can talk about two effects like tides or seasons and how gravity or Earth's movement causes them.

Curriculum links

• Science Understanding (Earth and space sciences): VC2S6U07 — gravity keeps planets in orbit; cyclic observable phenomena can be related to Earth’s tilt; rotation causes day and night.
• Science Inquiry (Processing, modelling and analysing): VC2S6I04 — using physical/visual models to show relationships and patterns.
• Science Inquiry (Communicating): VC2S6I06 — communicating ideas using scientific vocabulary and suitable formats for an audience.

Lesson structure (45 minutes)

1. 0–5 min · Hook (gravity myth check). Teacher displays two quick prompts: “Why doesn’t Earth fly off?” and “What would happen if gravity changed?” Students do a quick think-write, then turn and share one reason.

2. 5–15 min · Direct teach with demo (gravity + orbit). Teacher models orbit using a ball on a string or a “planet on track” analogy; explains gravity as an attractive force that pulls objects together, creating curved paths rather than straight-line escaping. Students sketch a simple “Sun pulling planet” diagram and label: gravity, orbit, curved path.

3. 15–22 min · Model practice (planets and moons in orbit). Teacher sets up a small simulation: students hold a ball (moon) tethered/positioned while the “planet” rotates; gravity provides the “pull” keeping it in a loop. Students work in pairs to complete a 3-step model explanation: (1) what pulls, (2) what moves, (3) what path results.

4. 22–30 min · Gravity effects on Earth (stations, short). Teacher runs three rapid stations (2–3 minutes each), then students rotate once:

• Station A: Tides — teacher shows images/diagram of tides and explains how the Moon’s gravity affects water levels; include Earth’s rotation in the explanation.
• Station B: Light intensity & day/night pattern — teacher uses a light source + globe to show how tilt changes the angle of sunlight and day length.
• Station C: Eclipses & “straight-line” alignment — teacher shows an eclipse alignment diagram and links to orbit/positioning; students identify “what lines up” in their words. Students record one key idea at each station using sentence starters.

5. 30–37 min · Space leaving Earth (thrust and payload ideas). Teacher explains simply: gravity pulls everything down toward Earth; a rocket needs thrust to overcome gravity and keep accelerating; payload is what the rocket carries once enough thrust is produced. Students answer: “How does gravity change what a rocket must do?” using a cause→effect sentence.

6. 37–43 min · Communicating task (mini science explanation). Students choose one Earth effect trio:

• Option 1: tides + seasons + variable day length
• Option 2: eclipses + light intensity + day/night changes Students write a 6–8 sentence explanation that includes gravity and Earth’s tilt/rotation (as appropriate). Teacher circulates with prompts for vocabulary and reasoning.

7. 43–45 min · Exit ticket (check for understanding). Students complete: “Gravity keeps orbits because ___.” and “Earth’s tilt/rotation affects ___ by ___.” Collect for quick review.

Resources

• Globe (or ball), small stand, and a desk lamp or torch (light source)
• Ball on string (or simple orbit model materials) and tray/paper for recording
• Printed station cards with diagrams for tides, light intensity/day-night, and eclipses (no long text)
• Sentence starter strips (e.g., “Gravity is a force that…”, “Earth’s tilt causes…”, “Because the Earth rotates…”)
• Student notebook or science journal, pencils/markers
• Timer for station rotation
• Optional: short image set of tides and eclipse alignment (printed)

Assessment

• Teacher listens during pair/model explanations for correct use of “gravity”, “orbit”, “tilt”, “rotation”, “curved path”, and “day/night length”.
• Station recording checks whether students can identify the correct cause (gravity/tilt/rotation) and effect (tides/seasons/light intensity/eclipses).
• Exit ticket confirms individual understanding and language accuracy.

Differentiation

• Use easy-to-read station cards with big letters, clear pictures, and less text; teacher can read instructions aloud slowly.
• Provide sentence starters and word banks with simple words: gravity, orbit, tilt, spin, seasons, day length, tides, eclipse, light, thrust, payload.
• Help students who need support by letting them draw first and then write labels and arrows.
• For students who want more challenge: ask them to compare two effects (like why tides change because of the Moon but seasons change because of Earth's tilt) and add one more example (like how sunrise and sunset times change).
• For English learners: use cause and effect charts, pair with a helpful friend, and allow speaking answers recorded by teacher or peer.

Extension activities

• Students make a short video or audio "science talk" for younger kids, using at least three words: gravity, orbit, tilt/spin, and one effect like tides or seasons.
• Advanced students fill a simple table: "Cause (gravity/tilt/spin) → What we see → Effect on Earth" and guess what would happen if Earth's tilt was bigger, like how seasons or day length might change.