Topic 11 – Exploring the Solar System
11.22 - Understand the resolution of a telescope is:
a) proportional to the diameter of the objective element
b) reduced by observing at a longer wavelength

Resolution is how a telescope will show the detail of an object being observed. To achieve higher resolution a large aperture is needed.

Resolution is dependent on the objective and proportional to its diameter.

A lot depends on the what determines resolution such as:

  • Diffraction of light caused by the atmosphere
  • Wavelength
  • Quality of Telescope
  • Contrast
  • Brightness
  • The observer’s quality of eyesight

A telescope’s resolution is sometimes referred to a its angular resolution or its resolving power. Astronomers might test this by seeing how two very closely related objects such as a double star separated by seconds of arc can be ‘resolved’ into two clear and separate objects.

Light travels in waves and when they enter an optical tube they will be affected by the telescope design. Longer wavelengths can cause distortion.

Resolution can be calculated by its Diameter and wavelength using the formula λ/D