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The Australian National University

Telescopes of Mt Stromlo

Observations at Mt Stromlo (Norman Banham Collection, Mt Stromlo Archives)
Sunset at Mt Stromlo Observatory, 1960s (Mt Stromlo Archives)
View of Observatory, 1965 (Mt Stromlo Archives)

How do they work?

On a dark night, you can see as far as the Andromeda galaxy with the naked eye, but it will appear to you as a tiny dot.

Telescopes allow us to see more detail in distant objects by acting as a bigger eye, capable of collecting more light.

The size of a telescope's lens or mirror determines the amount of light it will be able to collect. More light creates a brighter and more detailed image

Mt Stromlo's largest telescope had a primary mirror with a diameter of 74 inches (188cm).

There were two primary types of telescopes at the Mt Stromlo Observatory:

  • Refractors use a large lens to collect light and bend (refract) it into a single point of focus. Different wavelengths (or colours) of light refract at different angles, so the resulting image can be blurry or miscoloured.
  • Reflectors solve this problem by using a series of curved mirrors to reflect and focus the light, without needing it to be refracted. Large mirrors are also cheaper and easier to make than lenses, so reflecting telescopes can be used to look deeper into space.


Updated:  03 November 2014/Responsible Officer:  Director, Facilities & Services Division/Page Contact:  Systems & Information Technology