- Science
- Classes 3-5
- 4 min read
Our solar system
Tour the Sun and its eight planets in order, from Mercury to Neptune, and learn a few key facts about each one.
Let us begin
The big idea
Our Earth is one of many worlds that travel around a star we call the Sun. The Sun and everything that moves around it make up the solar system. Let us take a tour.
The Sun is a star. It is a huge ball of hot, glowing gas. It gives us light and heat. Everything in the solar system goes around the Sun.
There are eight planets. In order from the Sun they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Mercury is closest to the Sun and Neptune is farthest.
Mercury, Venus, Earth and Mars are rocky planets. Jupiter and Saturn are huge planets made mostly of gas. Uranus and Neptune are also giant planets and very cold. Jupiter is the biggest planet. Saturn has bright rings around it.
Earth is the third planet. It is the only planet we know that has living things. Earth turns once on its axis in about 24 hours, which gives us day and night. It takes about 365 days to go once round the Sun, which is one year.
A moon is a natural satellite that goes around a planet. Earth has one Moon. Pluto is no longer called a planet. It is a dwarf planet.
Worked examples
See how it works
Counting the order
From the Sun: 1 Mercury, 2 Venus, 3 Earth, 4 Mars, 5 Jupiter, 6 Saturn, 7 Uranus, 8 Neptune. So Mars is the fourth planet and Saturn is the sixth.
Which planets are neighbours of Earth?
Earth is third. The planet before it is Venus (second) and the planet after it is Mars (fourth). So Venus and Mars are Earth's neighbours.
Day and night
Earth spins around once in about 24 hours. The side facing the Sun has day. The side turned away has night.
Try it at home
Planet parade and a rhyme
You will need
- Paper
- Pencil or crayons
- Eight small household things of different sizes (like a rice grain, a pea, a marble, a small ball)
What to do
- Write the eight planet names on eight small slips of paper.
- Make your own short rhyme or sentence to remember the order. Use the first letter of each planet.
- Place a big round object (like a plate) on the floor as the Sun.
- Place the planet slips in order in a line going away from the Sun. Put small things on Mercury, Venus, Earth and Mars and bigger things on Jupiter and Saturn.
- Close your eyes and ask a family member to mix two slips. Can you put them back in the right order?
Ask a grown-up: IMPORTANT: Never look straight at the Sun, not even for a moment and not through glasses or binoculars. Draw the Sun from memory only.
Fun fact
Light from the Sun takes about 8 minutes to reach the Earth.
Practice sheet
Check what you learned
Practice sheet: Our solar system (Classes 3-5, Science)
- What is the Sun: a planet, a star or a moon?
- How many planets are there in our solar system?
- Which planet is closest to the Sun?
- Which is the third planet from the Sun?
- Which planet is the biggest?
- Which planet is famous for its bright rings?
- Which planet comes between Earth and Jupiter?
- Which planet is the farthest from the Sun?
- What is Pluto called now?
- How long does Earth take to go once around the Sun? How long does it take to spin once on its axis?
Answer key
Answers: Our solar system
- A star.
- Eight.
- Mercury.
- Earth.
- Jupiter.
- Saturn.
- Mars.
- Neptune.
- A dwarf planet.
- About 365 days to go round the Sun (one year); about 24 hours to spin once (one day).