8+

The Astronomer

A rusted metal sculpture of a man holding a ring up to the sky with one outstretched arm. Behind him is the corner of a large white building with dark windows and a cloudless blue sky.
A night time photo of a rusted metal sculpture of a man holding a ring up to the sky with one outstretched arm. There are gum trees lit up in the background and the sky is black with thousands of stars visible.

An artistic sculpture by Tim Wetherell, representing parallax to measure astronomical bodies and recovery from the 2003 Canberra Bushfires.

How it works

Study how the sculpture's figure is peering into the sky.

Things to try or ask around the exhibit

Why is the astronomer holding a ring?

Background

Mount Stromlo Observatory was destroyed during the 2003 bushfires in the ACT, including its historic eight metre-long Yale Columbia Refractor. The telescope was built in 1924 at Yale University (USA), arrived in Canberra in 1952 and was used until 1998 to make detailed measurements of stellar distances by parallax. Restoration was impossible, but some of the telescope’s surviving parts have been used to create this sculpture.

Finding the science in your world

Over the course of one year, the Earth orbits once around the Sun.

In Summer, Earth has moved roughly 300 million kilometres around from its Winter position. Because of this, nearby stars appear to move when viewed against the background of very distant stars.

By making very precise measurement of this movement, astronomers were able to calculate the distance of stars in the Southern sky. This is the first rung of what astronomers call the distance ladder used to establish the scale of the Universe.