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Topic 11: Telescopes and observatories

3 dot points across 3 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What sets how much a telescope can see and magnify, and how fine the detail is?

The light grasp and aperture of a telescope, the magnification formula using the focal lengths of objective and eyepiece, the field of view, and the resolution of a telescope.
A focused answer to Edexcel GCSE Astronomy statements 11.19 to 11.23, covering how light grasp depends on the square of the objective diameter, the aperture and field of view, the magnification formula (focal length of objective over focal length of eyepiece), and how resolution depends on aperture and wavelength.
11 min answer →

How does a telescope collect and focus light, and what are the main designs?

How a telescope's objective collects and focuses light for an eyepiece to magnify, the use of converging lenses and concave mirrors, and the main refracting and reflecting telescope designs.
A focused answer to Edexcel GCSE Astronomy statements 11.14 to 11.18 and 11.24 to 11.25, covering the limits of the human eye, how an objective lens or mirror collects and focuses light for an eyepiece, the main refracting (Galilean, Keplerian) and reflecting (Newtonian, Cassegrain) designs, the importance of Galileo's observations, and the advantages of reflectors over refractors.
10 min answer →

Why do we observe the Universe in radio, infrared, X-rays and gamma rays, and why put telescopes in space?

Astronomy across the electromagnetic spectrum, the optical and radio atmospheric windows, why the atmosphere harms observations, and the advantages and disadvantages of space telescopes.
A focused answer to Edexcel GCSE Astronomy statements 13.27 to 13.33, covering astronomy across the electromagnetic spectrum (radio, infrared, ultraviolet, X-ray and gamma ray), the optical and radio atmospheric windows, the detrimental effect of the atmosphere on telescope images, and the advantages and disadvantages of space telescopes.
10 min answer →