UNIT 3: STORIES AND PAST EVENTS
Recording 52, page 78
THE UNIVERSE
Exercise 1 Listen and read ... and think!
What is the Universe?
The Universe is everything that exists. The Earth is part of the Universe.
So are the Sun, the Moon and all the planets.
Scientists use telescopes and probes to learn about the Universe. We know a great deal, but there is still much that we do not know.
Before telescopes were invented, astronomers watched the sky with the naked eye.
They could not see as much as we can now, but they made many important discoveries.
Early astronomers thought that everything in the Universe circled around the Earth. They were wrong.
Later, a Polish astronomer, Copernicus, suggested that the Earth orbits, or circles, the Sun. But very few people believed him.
The Sun, our star
The Sun is a star and eight planets revolve around it.
We live on one of those planets, the Earth. We call the planets and the Sun the Solar System.
Before 2006, our Solar System had nine planets, but then scientists decided that Pluto was not really a planet.
The first planet, next to the Sun, is Mercury. It is 58 million kilometres from the Sun.
Venus is the second planet from the Sun, and our planet, the Earth, is the third.
It is 150 million kilometres from the Sun. It is between Venus and Mars.
Jupiter, Saturn, Neptune and Uranus are all bigger than the Earth, but Venus, Mars and Mercury are smaller.
Jupiter is so large that all the other planets would fit inside it. Saturn is very different from the other planets. It has rings around it.
The Earth is very special too. It is the only planet in our Solar System with water and air.
Although we cannot feel it, the Earth is always moving. It orbits, or circles, the Sun.
It takes one year for the Earth to travel all the way around the Sun.
At the same time, the Moon is circling the Earth. It takes the Moon about a month to travel around the Earth.
The Moon is a satellite of the Earth. It has not got any light of its own and it reflects the light of the Sun.
The Moon has no air or water. Nothing can live there.
But out in Space there are other Solar Systems and perhaps there are other planets with water and air.
Perhaps there are animals or people on these planets. What do you think?
Constellations are groups of stars. Some are named after animals (e.g. the Little Bear), others are named after ancient heroes or gods (e.g. Orion, The Hunter). There are 88 constellations across the whole sky. As Earth orbits the Sun, we can see the different constellations.
The Great Bear is a constellation. The seven brightest stars of the Great Bear form a pattern called the Plough or the Big Dipper.
Astronauts are travellers in Space. They collect information for scientists to study.
Probes do not carry any astronauts. They are sent on long journeys into Space and never return to Earth.
Rockets are used to carry things (e.g. satellites and probes) into Space. Rockets also launch astronauts into Space.
Satellites are spacecraft sent to orbit a planet. They collect information and radio back to Earth. Some bring us television pictures from the other side of the world. Others are used to help ships or planes find their way.
