Astronomy in the deep freeze
Box 1 | The Douglas Mawson Telescope
The man once featured on the Australian $100 note – Douglas Mawson – is our most famous Antarctic explorer. The Adelaide-based scientist was, arguably, the first Antarctic astronomer. The first meteorite discovered in Antarctica was found on his expedition of 1912. Mawson realised its origin and also the scientific significance of the discovery.
In 1954 Australia established its first permanent base in Antarctica and named it Mawson Station, in honour of the pioneering explorer. Now, almost fifty years later, the explorer seems set to be honoured again with plans for the Douglas Mawson Telescope. The telescope would establish Australia’s first permanent facility on the high Antarctic plateau, where most of the Australian territory lies.
The facility will be open to astronomers from Australia and overseas. Potential international partners include the United Kingdom, Germany, New Zealand and Argentina.
Features of the telescope
The diameter planned for the telescope is 2 metres, much larger than any existing telescope in Antarctica. The astronomers themselves will construct most of the detectors and other instruments required for the telescope. Importantly, the telescope can be loaded into a Hercules aircraft and transported from Australia to the Antarctic plateau.
The diameter of the telescope will be only half that of the 4 metre Anglo-Australian Telescope (AAT) at Siding Spring Mountain in New South Wales. Although the AAT makes observations at both optical and infrared wavelengths, it has to cope with a relatively turbulent atmosphere that distorts the images under investigation.
The observing conditions in Antarctica are so good that the performance of the Mawson telescope is expected to rival that of the AAT and other large telescopes in more temperate parts of the world, including 8 metre telescopes currently under construction in Hawaii and Chile.
There are likely to be attractive commercial spin-offs from building the telescope. Australian astronomers are at the forefront of designing and building instruments for their telescopes. With billions of dollars being invested in astronomical facilities worldwide, there is a growing and lucrative export market for Australian instruments and expertise.
South to the deep freeze
The likely site of the new telescope is at a location known as Dome C on the high plateau in the Australian Antarctic Territory, 1600 kilometres from the South Pole. The plateau has an average elevation of 3000 metres (higher than Australia’s highest mountain Mt Kosciuszko), rising to 3250 metres at Dome C. Strong winds are relatively rare here in the centre of the continent. (Antarctica’s famous blizzards are mainly a coastal phenomenon caused when snow is whipped up by cold, dense air cascading off the high interior plateau.)
The site at Dome C will be home to a major new French-Italian scientific base, Concordia Station, currently under construction. Astronomers and support staff reach the site by aircraft, departing from Australia’s Casey station.
Challenges ahead
A feature of the Douglas Mawson Telescope will be its wide field of view, enabling it to scan large sections of sky and quickly locate objects of interest. While larger and more expensive telescopes elsewhere can detect infrared radiation from more distant objects, their narrow field of view makes it difficult for them to make the initial discovery of these objects. The Mawson telescope will also play the role of a ‘finder’ telescope, locating previously unseen objects for other larger telescopes – both ground-based and in space orbit – to observe in more detail.
The telescope will have a busy research program ahead. Of particular interest are events such as the birth of galaxies and their subsequent evolution.
Another tantalising prospect is the study of the formation of individual stars and planetary systems in our own Milky Way. This may hold the key to how our solar system formed approximately 5 billion years ago and give some idea of the likelihood of Earth-like planets elsewhere in our Galaxy.
Box
Box 2. A different window on the universe
Related sites
The Douglas Mawson Telescope (University of New South Wales, Australia)
The Douglas Mawson Telescope (University of New South Wales, Australia)
Science goals for Antarctic infrared telescopes (M G Burton, J W V Storey and M C B Ashley, Electronic Publications of the Astronomical Society of Australia)
Posted August 2001.