Space physics
50 exam-style questions with answers for 4.8 Space physics in AQA GCSE Physics (spec 8463). Practise with flashcards, a topic quiz, a random quiz across the course, 5 crosswords, or read every question and answer below. Not official AQA material.
All 50 questions and answers
Question 1 · Spec 4.8.1.1 · Solar system
Name the star at the centre of our solar system. [1 mark]
Answer:The Sun.Question 2 · Spec 4.8.1.1 · Solar system
What is the solar system part of? [1 mark]
Answer:The Milky Way galaxy.Question 3 · Spec 4.8.1.1 · Solar system
What does the solar system contain? [2 marks]
Answer:One star, the Sun, with eight planets and dwarf planets orbiting it (1); and natural satellites (moons) orbiting planets (1).Question 4 · Spec 4.8.1.1 · Solar system
How was the Sun formed? [2 marks]
Answer:From a cloud of dust and gas (nebula) pulled together by gravitational attraction (1); the temperature and pressure rose until fusion began (1).Question 5 · Spec 4.8.1.1 · Main sequence
Why is a main sequence star stable? [2 marks]
Answer:The inward force of gravity (1); is balanced by the outward pressure from fusion energy (1).Question 6 · Spec 4.8.1.2 · Life cycle
Describe the life cycle of a star the size of the Sun. [3 marks]
Answer:Nebula → protostar → main sequence star (1); → red giant (1); → white dwarf → black dwarf (1).Question 7 · Spec 4.8.1.2 · Life cycle
Describe the life cycle of a star much larger than the Sun. [3 marks]
Answer:Nebula → protostar → main sequence star (1); → red super giant → supernova (1); → neutron star or black hole (1).Question 8 · Spec 4.8.1.2 · Elements
How are elements heavier than iron produced? [1 mark]
Answer:In a supernova.Question 9 · Spec 4.8.1.2 · Elements
How were elements distributed throughout the universe? [1 mark]
Answer:They were scattered by the explosion of massive stars (supernovae).Question 10 · Spec 4.8.1.2 · Fusion
Which elements are made by fusion in main sequence stars? [1 mark]
Answer:Helium, from hydrogen.Question 11 · Spec 4.8.1.2 · Black holes
What is a black hole? [1 mark]
Answer:A region where gravity is so strong that nothing, not even light, can escape.Question 12 · Spec 4.8.1.3 · Orbits
What force keeps planets and satellites in orbit? [1 mark]
Answer:Gravity.Question 13 · Spec 4.8.1.3 · Satellites
What is the difference between natural and artificial satellites? [2 marks]
Answer:Natural satellites, such as the Moon, occur naturally (1); artificial satellites are made by humans and placed in orbit (1).Question 14 · Spec 4.8.1.3 · Circular orbits · Higher only
Explain how gravity causes a changing velocity but unchanged speed in a circular orbit. [2 marks]
Answer:Gravity acts towards the centre at right angles to the motion, so the direction changes (1); no work is done in the direction of motion, so speed stays the same (1).Question 15 · Spec 4.8.1.3 · Orbits · Higher only
What happens to the speed of a satellite if its orbit radius decreases? [1 mark]
Answer:It must move faster to stay in a stable orbit.Question 16 · Spec 4.8.1.3 · Satellites
Give two uses of artificial satellites. [2 marks]
Answer:Any two from: communications (1); weather monitoring (1); GPS navigation (1); observing space (1).Question 17 · Spec 4.8.2 · Red-shift
What is red-shift? [1 mark]
Answer:An observed increase in the wavelength of light from galaxies moving away from us.Question 18 · Spec 4.8.2 · Red-shift
What does red-shift show about distant galaxies? [2 marks]
Answer:The further away galaxies are, the faster they are moving (1); and the bigger the observed increase in wavelength (1).Question 19 · Spec 4.8.2 · Big Bang
Describe the Big Bang theory. [2 marks]
Answer:The universe began from a very small region that was extremely hot and dense (1); it has been expanding ever since (1).Question 20 · Spec 4.8.2 · Big Bang
Why does red-shift support the Big Bang theory? [2 marks]
Answer:It shows that galaxies are moving away from us, so the universe is expanding (1); tracing this back suggests it began from a single point (1).Question 21 · Spec 4.8.2 · Dark matter
What is dark matter? [1 mark]
Answer:Matter that cannot be seen but is needed to explain how galaxies rotate; scientists do not yet know what it is.Question 22 · Spec 4.8.2 · Dark energy
What did observations of supernovae since 1998 suggest? [1 mark]
Answer:That distant galaxies are receding ever faster: the expansion is accelerating.Question 23 · Spec 4.8.2 · Science
Why do scientists still not fully understand the universe? [1 mark]
Answer:There is still much that is not understood, such as dark mass and dark energy.Question 24 · Spec 4.8.1.1 · Solar system
Name the eight planets in order from the Sun. [2 marks]
Answer:Mercury, Venus, Earth, Mars (1); Jupiter, Saturn, Uranus, Neptune (1).Question 25 · Spec 4.8.1.1 · Dwarf planets
Give an example of a dwarf planet. [1 mark]
Answer:Pluto.Question 26 · Spec 4.8.1.2 · Protostar
What is a protostar? [1 mark]
Answer:A hot ball of gas pulled together by gravity, before fusion begins.Question 27 · Spec 4.8.1.2 · Red giant
Why does a star become a red giant? [1 mark]
Answer:It runs out of hydrogen in its core, then expands and cools.Question 28 · Spec 4.8.1.2 · White dwarf
What is a white dwarf? [1 mark]
Answer:The small, hot, dense core left behind after a red giant sheds its outer layers.Question 29 · Spec 4.8.1.2 · Supernova
What is a supernova? [1 mark]
Answer:The explosion of a red super giant at the end of its life.Question 30 · Spec 4.8.1.2 · Neutron star
What is a neutron star? [1 mark]
Answer:The very dense core left after a supernova.Question 31 · Spec 4.8.1.3 · Moon
What does the Moon orbit? [1 mark]
Answer:The Earth.Question 32 · Spec 4.8.1.3 · Geostationary
What is a geostationary satellite? [2 marks]
Answer:A satellite that orbits above the equator once every 24 hours (1); so it stays above the same point on Earth, useful for communications (1).Question 33 · Spec 4.8.1.3 · Orbits
Why do planets further from the Sun take longer to orbit? [2 marks]
Answer:They travel a longer distance (1); and the Sun's gravity is weaker, so they move more slowly (1).Question 34 · Spec 4.8.2 · Red-shift
Why does light from a galaxy moving away appear redder? [1 mark]
Answer:Its wavelength is stretched as the galaxy moves away, shifting the light towards the red end of the spectrum.Question 35 · Spec 4.8.2 · Big Bang
What evidence other than red-shift supports the Big Bang? [1 mark]
Answer:Cosmic microwave background radiation.Question 36 · Spec 4.8.1.1 · Main sequence
What happens in the core of a main sequence star? [1 mark]
Answer:Hydrogen nuclei fuse to form helium, releasing energy.Question 37 · Spec 4.8.1.2 · Life cycle
What will happen to the Sun when it runs out of hydrogen? [1 mark]
Answer:It will become a red giant, then a white dwarf.Question 38 · Spec 4.8.1.2 · Life cycle
What determines a star's life cycle? [1 mark]
Answer:Its mass (size).Question 39 · Spec 4.8.1.3 · Moons
Name two planets that have moons. [2 marks]
Answer:Any two from: Earth (1); Mars (1); Jupiter (1); Saturn (1); Uranus (1); Neptune (1).Question 40 · Spec 4.8.2 · Expanding universe
What does it mean for the universe to be expanding? [1 mark]
Answer:The space between galaxies is increasing.Question 41 · Spec 4.8.2 · Red-shift
Who first showed that distant galaxies are moving away? [1 mark]
Answer:Edwin Hubble, in the 1920s.Question 42 · Spec 4.8.1.2 · Nebula
What is a nebula? [1 mark]
Answer:A cloud of dust and gas in space where stars form.Question 43 · Spec 4.8.1.2 · Elements
Why can fusion in a star not produce elements heavier than iron? [1 mark]
Answer:Fusing iron nuclei does not release energy, so heavier elements are only made in supernovae.Question 44 · Spec 4.8.1.3 · Orbits
What shape is the Moon's orbit around the Earth? [1 mark]
Answer:Almost circular.Question 45 · Spec 4.8.1.3 · Satellites
Why do low-orbit satellites move faster than geostationary ones? [1 mark]
Answer:They are closer to Earth, where gravity is stronger, so they must move faster to stay in orbit.Question 46 · Spec 4.8.2 · Big Bang
Roughly how old is the universe? [1 mark]
Answer:About 13.8 billion years.Question 47 · Spec 4.8.2 · Dark energy
What is dark energy? [1 mark]
Answer:An unknown form of energy thought to be causing the expansion of the universe to accelerate.Question 48 · Spec 4.8.1.2 · Life cycle
What is the final stage of a star the size of the Sun? [1 mark]
Answer:A black dwarf.Question 49 · Spec 4.8.1.1 · Solar system
What is a planet? [1 mark]
Answer:A large body orbiting a star, which has cleared its orbit of other objects.Question 50 · Spec 4.8.2 · Red-shift
What does it mean if light from a galaxy is blue-shifted? [1 mark]
Answer:The galaxy is moving towards us.