Do the preparation exercise first. Then read the text and do the other exercises.
Our solar system
Our solar system was formed about 4.5 billion years ago! But what exactly is the solar system? It consists of our sun and eight main planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. There are also moons, dwarf planets, asteroids, comets, rocks and dust.
All of the planets in the solar system orbit the sun. Mercury, Venus, Earth and Mars are called 'terrestrial planets'. They are mostly made of rock and metal. Jupiter, Saturn, Uranus and Neptune are called 'gas giants'. They are mostly composed of gas and they have rings. The smallest planet is Mercury and the biggest is Jupiter. Neptune is the coldest and Venus is the hottest planet.
Moons travel around planets. Earth has got just one moon, but there are at least 150 moons in our solar system. Jupiter and Saturn are the planets with the most - 53 confirmed moons each! Mercury and Venus have no moons at all.
Stars are enormous balls of very hot gas. Our closest star is the sun, and it's 150 million km away from planet Earth! Without the sun's energy, there would be no life on Earth.
Yuri Gagarin became the first human to travel in space in 1961. Then, in 1969, astronauts Neil Armstrong and Buzz Aldrin landed on the moon as part of the Apollo 11 mission. There have been many more missions to space since!
Did you know ...?
An easy way to remember the order of the planets is to use a special sentence, such as 'My Very Educated Mother Just Served Us Noodles'. The first letter of each word is the first letter of each planet. Or you could make up your own sentence!
Can you think of another sentence that helps you remember the order of the planets? Tell us what it is!