Page 29 - Exercise 1B

Page 29 - Exercise 1B

The Solar System

There are eight planets in our solar system. Until 2006 there were nine. But scientists decided that Pluto wasn’t big enough to be a planet.

At the centre of our solar system is the Sun. The Sun is one of billions of stars in our galaxy - The Milky Way. It isn’t a very big star, but it’s over one hundred times bigger than the Earth. The Earth is approximately 150 million kilometres from the Sun. All the planets are in orbit around the Sun. That means they go round the Sun.

Mars is often called I the ‘Red Planet’. It’s smaller than the Earth I and much colder, but some scientists think f that there was water on Mars a long time ago - I and possibly life, too.

The large planets - Jupiter, Saturn, Uranus and Neptune - are made of gas. Neptune is the furthest planet from the Sun. Temperatures can fall to -219°C. Neptune takes 165 years to go round the Sun.

The nearest planet to the Sun is Mercury. It’s also the smallest planet.

Venus is about the same size as the Earth and it’s our nearest neighbour, but it’s very different. Venus has a thick, poisonous atmosphere and nothing can live there. The temperature on Venus is about 460 Celsius.

The Earth has a diameter of 12,756 km. It takes approximately 365 days to go round the Sun.

Jupiter is the largest planet. Its diameter is 143000 kilometers. Jupiter has got 4 large moons and many more small ones. There’s a large red spot on its surface. Scientists think it’s a huge storm.