List the planets of the solar system in order from the Sun.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Space Physics
8 exam-style questions on the solar system, life cycle of stars, red-shift and the Big Bang. Tap Show answer for full working.
3 Easy3 Medium2 Hard
What is the force that keeps planets in orbit around the Sun?
Gravity (gravitational force between the Sun and the planet).
State what is meant by red-shift of light from distant galaxies.
The observed increase in wavelength (shift towards the red end of the spectrum) of light from galaxies that are moving away from us.
Describe the life cycle of a star the size of the Sun, from formation to its final stage.
Nebula → protostar → main sequence star → red giant → planetary nebula → white dwarf.
How does the life cycle of a much more massive star differ from that of the Sun after the main sequence stage?
It becomes a red supergiant, then may explode as a supernova, leaving a neutron star or black hole (instead of a white dwarf).
Explain how red-shift provides evidence for the expanding universe.
Light from most galaxies is red-shifted, showing they are moving away from us. More distant galaxies show greater red-shift (moving away faster). This suggests the universe is expanding.
Describe the Big Bang theory and state two pieces of evidence that support it.
The universe began from a very hot, dense state and has been expanding ever since.
Evidence: red-shift of galaxies (expansion); cosmic microwave background radiation (leftover heat from the early universe).
Explain why the Sun is stable during its main sequence stage. Include the forces involved.
Outward pressure from the energy released by nuclear fusion in the core balances the inward gravitational force. This equilibrium keeps the star stable for billions of years.