P2f: Exploring our Solar System

Question 1

Explain why stars can be seen or detected even though they are far away

Answer 1

their high temperatures mean they emit lots of light

Question 2

Sizes of planets, stars, comets, meteors, galaxies and black holes in ascending order

Answer 2

meteors, comets, black holes, planets, stars, galaxies

Question 3

What does circular motion require?

Answer 3

centripetal force

Question 4

What provides the centripetal force for orbital motion

Answer 4

gravitational attraction

Question 5

Why is a light-year used?

Answer 5

useful unit for measuring very large distances in space as distances between objects in space are too large for units like km

Question 6

Difficulties of manned space travel between planets (5)

Answer 6

spacecraft needing to carry lots of fuel, food, water, oxygen (or recycle them); heavy, expensive

spacecraft needs to regulate temp and remove toxic gases from air

spacecraft needs to shield astronauts from radiation in space

long periods in low gravity leads to muscle wastage and loss of bone tissue

psychologically stressful spending ages in a tiny space with same people

Question 7

Advantages of using unmanned spacecraft to explore the Solar System (5)

Answer 7

don’t have to carry food, water or oxygen

can withstand conditions that would be lethal to humans (extreme heat, cold, radiation)

less people taking up room/weight; more instruments can be fitted in

cheaper - carry less and don’t need to come back to Earth; less spent on safety

no one gets hurt if the probe meets with an accident

Question 8

Disadvantages of using unmanned spacecraft to explore the Solar System (2)

Answer 8

can’t think for themselves while humans are good at overcoming simple problems that could be disastrous

can’t do maintenance and repairs but people can

Question 9

Compare how information from space is returned to Earth from different distances (3)

Answer 9

distant planets require data to be transmitted back via radio waves as it would take too long for the spacecraft itself to travel back to Earth
-radio signals still take a long time to travel through the solar system

nearby samples collected by people/probes can be physically brought back to Earth for analysis.