Explain why the development of space-based telescopes, such as those placed in orbit around the Earth, has improved astronomers' ability to observe objects across different parts of the electromagnetic spectrum compared with ground-based telescopes.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (5 marks)
1. The Earth's atmosphere absorbs or blocks many wavelengths of the electromagnetic spectrum, preventing them from reaching the ground.
2. Space‑based telescopes are above the atmosphere, so radiation reaches the telescope without being absorbed.
3. This allows observation of wavelengths that cannot reach ground‑based telescopes, such as X‑rays, gamma rays, ultraviolet and far‑infrared.
4. In space there is no atmospheric distortion or turbulence, so images are clearer and sharper.
5. Consequently astronomers obtain more detailed and accurate information about distant objects and the universe.
2. Space‑based telescopes are above the atmosphere, so radiation reaches the telescope without being absorbed.
3. This allows observation of wavelengths that cannot reach ground‑based telescopes, such as X‑rays, gamma rays, ultraviolet and far‑infrared.
4. In space there is no atmospheric distortion or turbulence, so images are clearer and sharper.
5. Consequently astronomers obtain more detailed and accurate information about distant objects and the universe.
Examiner tips
- Use the exact wording from the mark scheme (e.g. "absorbs or blocks", "no atmospheric distortion").
- Show the five points clearly, each addressing one scheme point.
- Keep sentences concise and avoid unnecessary words.
Common mistakes
- Confusing ground‑based advantages with space advantages, e.g. saying space telescopes have better resolution because of larger mirrors.
- Omitting the specific wavelengths (X‑ray, gamma‑ray, UV, IR) that are blocked by the atmosphere.
Mark scheme (5 marks)
- The atmosphere absorbs or blocks many wavelengths / parts of the electromagnetic spectrum
- Space-based telescopes are above the atmosphere, so radiation reaches the telescope without being absorbed
- This allows observation of wavelengths / types of radiation (e.g. X-rays, gamma rays, ultraviolet, infrared) that cannot reach ground-based telescopes
- There is no atmospheric distortion / turbulence in space, so images are clearer / sharper
- This gives astronomers more detailed / accurate information about distant objects / the universe
Key terms in this question
electromagnetic spectrum · space-based telescope
Related
- All AQA A-Level Physics (7408) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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