Compare the uses of a low Earth orbit (LEO) satellite with a geostationary satellite, explaining why each orbit is suited to its purpose.

AQA GCSE Physics (8463) — 4.8.1 Solar system; stability of orbital motions; satellites (Phys only) · Compare · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

LEO satellites are used for monitoring and imaging the Earth’s surface, such as weather, reconnaissance and Earth‑observation missions. They orbit at low altitudes (≈200–2000 km) so they can capture high‑resolution, detailed images of the surface.

Geostationary satellites are used for communications, television broadcasting and GPS. They orbit at the geostationary altitude (≈35 800 km) directly above the equator and remain above the same point on Earth, giving a fixed position for dish or receiver alignment.

Thus LEO satellites are suited to detailed imaging because of their proximity to the surface, while geostationary satellites are suited to continuous coverage and fixed communication links because of their constant position relative to the Earth.

Examiner tips

  • Use the command word ‘compare’ – list each orbit’s main use and explain the reason for the suitability.
  • Show the altitude difference and link it to resolution or fixed position.
  • Use exact terms: ‘low Earth orbit’, ‘geostationary orbit’, ‘high‑resolution images’, ‘fixed position’.

Common mistakes

  • Mixing up the purposes – e.g. saying LEO is for communications or geostationary for imaging.
  • Failing to explain why altitude matters – just stating uses without the reasoning.
  • Using vague language such as ‘good’ or ‘better’ without specifying resolution or fixed position.

Mark scheme (4 marks)

  1. LEO satellites are used for monitoring / imaging the Earth's surface (e.g. weather, reconnaissance, Earth observation)
  2. LEO satellites orbit at lower altitude so they can produce higher-resolution / more detailed images of the surface
  3. Geostationary satellites are used for communications / television broadcasting / GPS
  4. Geostationary satellites remain above the same point on Earth / have a fixed position relative to Earth, so a dish/receiver can be aimed permanently at them

Key terms in this question

low Earth orbit · geostationary satellite · orbit

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