Questions on the Earth in Space

Q12.

The diagram below shows the orbits of Neptune, Pluto and the Earth. At two points, A and B, the orbits of Neptune and Pluto cross over each other. The diagram is not to scale.

(a) What force keeps planets in orbit around the Sun?

1 mark

(b) Give two reasons why it takes Pluto more time than Neptune to orbit the Sun.

2 marks

(c)

(i) Tom can see the Sun because it is a light source. It gives out its own light. Neptune and Pluto are not light sources but Tom can see them when he looks through his telescope. Explain why Tom can see Neptune and Pluto even though they are not light sources.

2 marks

(ii) Between points A and B, Pluto is nearer than Neptune to the Earth. Tom noticed that Pluto is not as bright as Neptune, even when Pluto is closer than Neptune to the Earth. Give one reason why Pluto is not as bright as Neptune.

1 mark

Maximum 6 marks