How to teach the solar system
Grade 1 to Grade 5
The solar system is the Sun and everything that orbits it: eight planets, their moons, and smaller bodies like asteroids and comets. Start young students with what they can see (the Sun, the Moon, stars) and build up to the order of the planets and why they stay in orbit.
How to teach it
- Begin with the familiar: the Sun gives light and heat, the Moon orbits Earth, and the tiny lights at night are distant stars.
- Teach the eight planets in order from the Sun (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune), a mnemonic like 'My Very Easy Method Just Speeds Up Naming' helps.
- Sort the planets into the four small rocky planets (closest) and the four giant gas and ice planets (farthest).
- Explain that gravity is the pull that keeps each planet moving along its orbit around the Sun.
- Correct the common myths: Pluto is now a dwarf planet, and Venus (not Mercury) is the hottest because of its thick atmosphere.
Common mistakes
- Thinking Mercury is the hottest planet, Venus is, because of its heat-trapping atmosphere.
- Still counting Pluto as the ninth planet (it is a dwarf planet).
- Mixing up a star (like the Sun) with a planet (which does not make its own light).
- Getting the planet order wrong, especially swapping the outer gas giants.
Frequently asked questions
What are the eight planets in order?
In order from the Sun, the eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The mnemonic 'My Very Easy Method Just Speeds Up Naming' helps students remember the sequence. The first four are small and rocky, and the outer four are giant gas and ice planets.
What age or grade is the solar system taught?
The solar system is usually taught from Grade 1 to Grade 5. Younger students start with what they can see, the Sun, the Moon and stars, while older students learn the order of the planets, the difference between rocky and gas planets, and why gravity keeps everything in orbit.
Is Pluto a planet?
No. Pluto is now classed as a dwarf planet, not one of the eight main planets. It was reclassified in 2006 because it has not cleared its orbit of other objects. Many older books still show nine planets, so this is a common point of confusion for students.
Which is the hottest planet?
Venus is the hottest planet, not Mercury, even though Mercury is closer to the Sun. Venus has a thick atmosphere that traps heat like a blanket, pushing its surface temperature higher than Mercury's. Assuming the closest planet must be the hottest is a very common misconception.
What keeps the planets in orbit around the Sun?
Gravity keeps each planet in orbit. The Sun's gravity pulls on every planet, bending its path into a curved orbit rather than letting it fly off in a straight line. The planets keep moving, so gravity holds them circling the Sun instead of pulling them straight in.
What is the difference between a star and a planet?
A star, like the Sun, makes its own light and heat. A planet does not make its own light; it only reflects the light of a star. So the Sun is a star, while Earth and the other planets orbit it and shine only by reflected sunlight.
What is the difference between the rocky and gas planets?
The four planets closest to the Sun, Mercury, Venus, Earth and Mars, are small and rocky with solid surfaces. The four farthest out, Jupiter, Saturn, Uranus and Neptune, are giant planets made mostly of gas and ice with no solid surface to stand on.
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