4.2 To discuss the planets of our solar system  (Page 2/5)

• Mars

Mars is also called the Red Planet because the iron on its surface gives off a red glow. The atmosphere is about 100 times less dense than that of the earth. It consists of carbon dioxide with very small quantities of water vapour. Ice fields form at a temperature of –125 degrees Celsius in winter. Summer temperatures reach a maximum of 20 degrees Celsius.

Illustration of the position of the planets in the solar system

THE OUTER PLANETS

• Jupiter

Jupiter contains 300 times as much matter as the earth and is the largest planet in the solar system. Jupiter is a giant ball of liquid gas and possibly has no solid surface. The only features that can be seen through a telescope are coloured stripes of clouds stretching around Jupiter. Jupiter has a large red spot known as the Red Spot. It is a tornado (a storm) which rages permanently and covers an area greater than the earth’s surface.

• Saturn

Saturn is the second gas giant and is very much like Jupiter. It consists mainly of hydrogen and helium with a surface temperature of –170 degrees Celsius. Saturn’s spectacular rings make it one of the brightest objects in our solar system. The rings move around the equator of Saturn in a very thin band. They consist of millions of pieces of ice, almost like snowballs. Saturn has seventeen moons of which Titan is probably the largest in our solar system. Two Voyager spacecraft have already been dispatched to explore the outer planets. Saturn is eight times further from us than the sun. It takes the radio signals from the spacecraft more than an hour to reach the earth.

• Uranus, Neptune and Pluto

These three planets are very far from the earth and are known as the ice giants. Surface temperatures vary between –197 degrees Celsius to –233 degrees Celsius.

Task 4

• Use the initial letters of the names of the planets, (M, V, E, M, J, S, U, N, P) to make a rhyme or story to help you remember the order of the planets.

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

TASK 5

Answer the following questions:

1. Which planet becomes so hot that lead would melt on its surface?

_____________________________________________________________________

2. Give two reasons why life as we know it is impossible on Mars.

_____________________________________________________________________

_____________________________________________________________________

3. Why is Venus sometimes called Earth’s twin?

_____________________________________________________________________

_____________________________________________________________________