3 Fig. 3.1 shows a spacecraft taking off from the Moon. rocket engine Fig. 3.1 (a) The total mass of the spacecraft is 5000 kg. (i) The gravitational field strength on the Moon is 1.6 N / kg. Calculate the weight of the spacecraft on the Moon. weight = … N [1] (ii) The rocket engine pushes the spacecraft vertically upwards with a constant force of 15 000 N. Calculate the work done by the rocket engine to move the spacecraft to a height of 500 m. work done = … J [2] (iii) Use your answer to (a)(i) to calculate the gravitational potential energy gained by the spacecraft at 500 m above the Moon’s surface. gravitational potential energy = … J [2] (iv) Explain the difference between your answers to (a)(ii) and (a)(iii). … … [1] (b) Fig. 3.2 shows two large mirrors left behind on the Moon’s surface. The two mirrors are arranged at 90° to each other. A laser light beam from the Earth can be reflected back to the Earth by the mirrors. This enables the distance between the Earth and the Moon to be measured. mirror mirror incident ray of light from Earth Fig. 3.2 (i) On Fig. 3.2 complete the ray diagram to show how the ray of light is reflected back parallel to the incident ray. [2] (ii) Light takes 2.56 s to travel from the Earth to the Moon and back again. The speed of electromagnetic waves in space is 3.00 × 105 km / s. Calculate the distance from the Earth to the Moon. distance = … km [2] [Total: 10]

3(a)(i) (weight = 5000 × 1.6 =) 8000 (N) ; 1 3(a)(ii) (work done =) force × distance = 15 000 × 500 ; = 7500000 (J) ; 2 3(a)(iii) (gravitational PE gained =) weight × height = 8000 × 500 ; = 4000000 (J) ; 2 3(a)(iv) difference (7 500 000J – 4 000 000J = 3 500 000 J) = kinetic energy of the spacecraft ; 1 3(b)(i) 2 reflections at first and second mirrors ; angles of reflection roughly 45° for both reflections, and emergent ray parallel to incident ray ; 3(b)(ii) distance travelled in 2.56 s = 3.00 × 105 × 2.56 (= 7.68 × 105 km for there and back again) ; (distance from the Earth to the Moon (= 1 2 × 7.68 × 105) = 3.84 × 105 km / 384 000 km ; 2 (a)(i) To earn this mark, correctly calculate the weight by multiplying mass by gravitational field strength. (a)(ii) To earn these marks, show the calculation of work done by multiplying force by distance, and then state the correct numerical answer. (a)(iii) To earn these marks, show the calculation of gravitational potential energy gained by multiplying weight by height, and then state the correct numerical answer. (a)(iv) To earn this mark, explain that the difference between the work done and the gravitational potential energy gained is the kinetic energy of the spacecraft. (b)(i) To earn these marks, draw two reflections, one at each mirror, with angles of reflection roughly 45 degrees, resulting in an emergent ray parallel to the incident ray. (b)(ii) To earn these marks, calculate the total distance travelled by the laser light and then divide it by two to find the distance from the Earth to the Moon.

6 Fig. 6.1 shows a space telescope for detecting gamma radiation from distant stars. Fig. 6.1 (a) Fig 6.2 shows the position of gamma radiation in the electromagnetic spectrum. On Fig 6.2, write • a tick (✓) underneath the radiation with the lowest frequency • a cross (✗) underneath the radiation that causes sunburn. gamma radiation X-rays ultraviolet visible light infra-red microwaves radio waves Fig. 6.2 [2] (b) A star that emits gamma radiation is billions of kilometres away from Earth. (i) The gamma radiation received by the space telescope today gives astronomers information about the star as it was in the past. Explain why it does not give astronomers information about the star as it is today. … … [1] (ii) The astronomer measures the wavelength of the gamma radiation received. The wavelength of the gamma radiation is 2.0 × 10–14 m. The speed of the gamma radiation is 3.0 × 108 m / s. Calculate the frequency of the gamma radiation. frequency = … Hz [2] (c) Fig. 6.3 shows three penguins on a clear, sunny day. Fig. 6.3 Radiation from the Sun heats some parts of the penguins’ bodies more than other parts. (i) Name the electromagnetic radiation from the Sun that is mainly responsible for this heating effect. … [1] (ii) Suggest which parts of the penguins’ bodies are heated more than other parts. Give a reason for your answer. … … … [1] [Total: 7]

6(a) gamma X-rays ultraviolet visible light infrared microwaves radio waves x ✓ lowest frequency: tick in correct place ; causes sunburn: cross in correct place ; 2 6(b)(i) (even at speed of light) it takes the gamma radiation a (very) long time to travel (billions of kilometres) ; 1 6(b)(ii) v = f λ in any form / 3.0 × 108 ÷ 2.0 × 10–14 ; 1.5 × 1022 (Hz) ; 2 6(c)(i) infrared ; 1 6(c)(ii) back / wings / head / darker areas, because black is a good absorber (of radiation) / ORA ; 1 (a) To earn these marks, you must place a tick under radio waves for the lowest frequency and a cross under ultraviolet for the radiation that causes sunburn. (b)(i) To earn this mark, you must explain that it takes a very long time for gamma radiation to travel billions of kilometers, even at the speed of light. (b)(ii) To earn these marks, you must correctly apply the wave equation (v = fλ) and calculate the correct frequency. (c)(i) To earn this mark, you must name infrared as the electromagnetic radiation from the Sun that heats the penguins. (c)(ii) To earn this mark, you must identify the darker areas (like the back, wings, or head) as heating more because black is a good absorber of radiation.

6 Table 6.1 gives some data about the planets Earth, Mars and Venus. Table 6.1 Earth Mars Venus surface temperature 15 °C – 63 °C 462 °C average distance from the Sun 150 × 106 km 225 × 106 km 108 × 106 km time for one orbit around the Sun 365 days 687 days 225 days (a) (i) Use Table 6.1 to deduce which of these planets could have liquid water on the surface. … [1] (ii) Use data from Table 6.1 to explain your answer to (i). … … … [2] (b) (i) State the method of thermal energy transfer from the Sun to these planets. … … [1] (ii) Explain why other methods of energy transfer cannot transfer thermal energy from the Sun to these planets. … … [1] (c) The Earth travels a distance of 940 million kilometres in one orbit around the Sun. Use data from Table 6.1 to calculate the speed in kilometres / hour (km / h) at which the Earth travels around the Sun. Show your working. speed = … km / h [3] (d) At the Earth’s surface the Sun’s energy is not usually sufficient to start a fire. If the Sun’s rays are focused by a lens, they can cause a fire. On Fig. 6.1, complete the ray diagram to show how a lens can focus the Sun’s rays and set fire to some dry grass. You should draw two complete rays. lens rays from the Sun dry grass Fig. 6.1 [2] [Total: 10]

6(a)(i) Earth (only) ; 1 6(a)(ii) (data selected from the table to show) any two from: temperature on surface of Earth is above melting point of water ; temperature on surface of Earth is below boiling point of water ; temperature on Venus higher than boiling point of water (at 100 °C) ; temperature on Mars lower than melting point of water (at 0 °C) ; 2 6(b)(i) (infrared) radiation ; 1 6(b)(ii) (conduction and convection) need a medium to travel through / no medium in space ; 1 6(c) time in hours = 365 x 24 ; speed = distance / time or 940 × 106 / 365 × 24 ; = 107 306 / 107 000 (km/h) ; 3 6(d) two converging rays ; coming to a focus at the burning grass; 2 (a)(i) You must identify 'Earth (only)' to earn this mark. (a)(ii) You need to select data from the table and explain that Earth's surface temperature is above water's melting point and below its boiling point, or that Venus is too hot and Mars is too cold for liquid water, to earn both marks. (b)(i) You must state '(infrared) radiation' to earn this mark. (b)(ii) You must explain that conduction and convection 'need a medium to travel through' and there is 'no medium in space' to earn this mark. (c) You must correctly calculate the time in hours (365 x 24), use the formula speed = distance/time, and arrive at the correct answer of 107 306 or 107 000 (km/h) to earn all three marks. (d) You need to draw two converging rays that come to a focus at the burning grass to earn both marks.

6 Table 6.1 gives some data about the planets Earth, Mars, Mercury and Venus. Table 6.1 Earth Mars Mercury Venus mass 5.97 × 1024 kg 6.42 × 1023 kg 3.29 × 1023 kg 4.87 × 1024 kg volume 1.08 × 1021 m3 1.63 × 1020 m3 6.08 × 1019 m3 9.28 × 1020 m3 gravitational field strength g 9.81 N / kg 3.71 N / kg 3.70 N / kg 8.87 N / kg mean temperature at surface 15 °C –63 °C 167 °C 462 °C pressure of atmosphere 101 000 N / m2 600 N / m2 0 9 300 000 N / m2 percentage of Sun’s radiation reflected 31% 25% 7% 69% (a) Use data from Table 6.1 to state which planet has the greatest volume. … [1] (b) Use data from Table 6.1 to calculate the density of Mercury. Show your working and give the units of your answer. density = … units … [3] (c) A mass of 5 kg is placed on each planet, 10 m above the planet’s surface. State on which planet this mass has the greatest gravitational potential energy. Give a reason for your answer. planet … reason … … [2] (d) The surface of a planet reflects a percentage of the Sun’s radiation back into space. The rest of the radiation is absorbed by the planet. Suggest one reason why the percentage of the Sun’s radiation reflected by the surface of Mercury is so low. … [1] (e) A space probe of mass 50 kg descends through the atmosphere on Venus. The probe is slowed down by the atmosphere much more than it would be by the resistance of the Earth’s atmosphere. Use data from Table 6.1 to explain this in terms of difference in the arrangement of the molecules in the atmosphere. … … … … [2] [Total: 9]

6(a) Earth ; 1 6(b) use of d = m/V ; (3.29 × 1023 / 0.608 × 1020) = 5.41 × 103 (3sf) ; kg/m3 ; 3 6(c) Earth ; greatest mass / highest gravitational field strength ; 2 6(d) darker colour / duller surface ; 1 6(e) (on Venus) pressure of atmosphere much higher so molecules more concentrated ; so (atmospheric) resistance is greater / more work done by probe pushing molecules aside / owtte ; ORA 2 (a) To earn this mark, you must identify 'Earth' as the planet with the greatest volume from the table. (b) To earn these marks, you must use the formula density = mass/volume, correctly substitute the values for Mercury, calculate the density as 5.41 × 10^3, and state the correct units as kg/m^3. (c) To earn these marks, you must state 'Earth' as the planet where the mass has the greatest gravitational potential energy and provide the reason that Earth has the greatest mass or highest gravitational field strength.

33 How is thermal energy transferred from the Sun to the Earth through the vacuum of space? A by conduction, convection and radiation B by conduction only C by convection only D by radiation only

Answer: D To earn the mark, you must correctly identify that thermal energy is transferred from the Sun to Earth through the vacuum of space solely by radiation.

Cambridge IGCSE Combined Science · 0653

IGCSE Combined Science (0653) Space physics past paper questions

Revise IGCSE Combined Science (0653) — Space physics with real Cambridge past-paper questions grouped by topic, each shown with its marking scheme. Working one topic at a time targets exactly the skill each question tests.

11 free questions from 2017–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.

Space physics in IGCSE Combined Science 0653 exams, 2020–2025

Across 2020–2025, Space physics accounted for 33 questions worth 156 marks in Cambridge IGCSE Combined Science (0653) papers.

By year
Year	Questions	Marks
2020	2	17
2021	3	3
2022	0	0
2023	2	12
2024	3	18
2025	23	106

Most-tested subtopics

P5.1 The Solar System130 marks
P5.2 Stars and the Universe71 marks

Appears in

Paper 1 · 6 qs
Paper 2 · 12 qs
Paper 3 · 5 qs
Paper 4 · 10 qs

All most-tested Combined Science topics

2020 May/Jun · Paper 4 · Q3 · 10 marks
Marking scheme
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2020 Oct/Nov · Paper 4 · Q6 · 7 marks
Marking scheme
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2019 Oct/Nov · Paper 3 · Q6 · 10 marks
Marking scheme
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2019 Oct/Nov · Paper 4 · Q6 · 9 marks
Marking scheme
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2021 Feb/Mar · Paper 1 · Q33 · 1 mark
Marking scheme
Mark scheme — 2021 Paper 1 Q33
Answer: D
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