Class 5 · Environmental Studies
The Sun and its family of planets
Eight planets travel around the Sun. Explore their order, size and how long each takes to go around once.
🎯 You will learn to
- Name the eight planets in order from the Sun
- Tell the difference between a star, a planet and a moon
- Explain why planets far from the Sun take longer to complete an orbit
The Sun is a star: a huge ball of very hot gas that gives out its own light and heat. Everything that moves around the Sun because of its pull (gravity) forms the solar system.
The eight planets
- Mercury, Venus, Earth and Mars are small and rocky.
- Jupiter and Saturn are giant planets made mostly of gas.
- Uranus and Neptune are icy giants far from the Sun.
A moon is a natural object that goes around a planet. Earth has one Moon; Jupiter and Saturn have many.
The farther a planet is from the Sun, the longer its path and the slower it moves, so its year is longer. Earth takes about 365 days; Neptune takes about 165 Earth years.
📌 Remember for the exam
- Order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
- The Sun is a star; planets shine only by reflecting sunlight
- The 3D model is not to scale: real distances are far larger
🎯 Learning objective: Name the planets in order and compare their sizes and years.
💬 Questions and answers
1What am I looking at?
Answer: The Sun and its eight planets orbiting it (not to scale).
2What are its parts? (click a part to identify it)
Answer: Sun; rocky planets Mercury, Venus, Earth, Mars; gas giants Jupiter, Saturn; ice giants Uranus, Neptune; Earth's Moon.
3How does it work?
Answer: Gravity of the Sun keeps planets in orbit. Planets farther away travel longer paths more slowly, so their years are longer.
4Why is it important?
Answer: It explains day and year, eclipses, seasons and space missions like Chandrayaan and Mangalyaan.
5What happens if I change something? (use the sliders)
Answer: Use the speed slider and click planets to read facts about each.
6What should I remember for the exam?
Answer: Order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Largest: Jupiter; hottest: Venus; red planet: Mars.