Questions on the Earth in Space

Q19. In 1610, the Italian scientist, Galileo, observed four bright moons near Jupiter. Each night the moons had moved.

(a)

(i) The Sun and stars are light sources, and the planets are seen by reflected light. Explain how we can see the moons of Jupiter.

3 marks

(ii) The four moons are approximately the same distance from the Earth. However, they do not have the same brightness. Suggest one reason for this.

1 mark

(b) The table below shows the distances of the four moons from the centre of Jupiter, and the times of their orbits. (Europa's distance has been left out).

name of
moon

distance from
Jupiter, in
millions of km

time for one
orbit, in
Earth days

Io

0.42

1.8

Europa

 

3.6

Ganymede

1.07

7.2

Callisto

1.88

16.7

The graph below was plotted using the information in the table. Use the graph to estimate Europa's distance from Jupiter.

1 mark

(c) Galileo realised that Jupiter and its moons formed a model of our Solar System. In this model:

(i) what did Jupiter represent?

(ii) what did the moons represent?

2 marks

Maximum 7 marks