Tests by a team from the University of New South Wales, reported in the journal Nature this week [16 September], show that the Dome C site in the Australian Antarctic Territory is by far the best place ever tested on Earth for doing infrared and optical astronomy.

"A telescope there would perform as well as a much larger one anywhere else on Earth. It's nearly as good as being in space", said Dr. Will Saunders of the Anglo-Australian Observatory.

At the SPIE Astronomical Telescopes and Instrumentation conference in Glasgow in June, Dr. Saunders presented a concept for an unusual telescope that's well matched to the special conditions at Dome C, both in its optical design and in the way it's built.

It looks nothing like other telescopes. Much of it could be built of icecrete-snow compressed to form blocks as hard as concrete - while its mirrors could be made of the glass used for office windows.

Under the superb atmospheric conditions at Dome C this simple telescope could make razor-sharp images of large areas of sky.

Dr. Saunders estimates that his design would cost about a fifth as much as one of the extremely large telescopes now being planned. These have mirrors 30-100 m in diameter and price tags of US$700 million and up. The Hubble Space Telescope cost a few times more: about US$2.2 billion at launch.

"With this simple telescope you could do the exquisite imaging that the extremely large telescopes plan to do, at a fraction of their cost" Dr. Saunders said. "But, unlike them, this telescope would also be a great survey instrument, able to map the whole sky with Hubble-like clarity."

IMAGES

Available at ftp://ftp.aao.gov.au/pub/local/will/what/

Concept overview Small (25 K) ftp://ftp.aao.gov.au/pub/local/will/what/what-spie-overview_150.jpg

Medium (235 K) ftp://ftp.aao.gov.au/pub/local/will/what/what-overview_horiz.jpg

Large (591 K) ftp://ftp.aao.gov.au/pub/local/will/what/what_overview_horiz3.jpg

On the right is the corrector: a nearly flat, steerable reflector. This receives the light from the sky and directs it onto the primary mirror, over at the left. The primary focuses the light onto a prime focus unit lying halfway between the two mirrors. The prime focus unit could be a number of things: a camera, a device that holds optical fibres for capturing the light, or a secondary mirror reflecting the light through a central hole in the primary mirror. Credit: Andrew McGrath, AAO

Telescope corrector

Small (29 K) ftp://ftp.aao.gov.au/pub/local/will/what/what_corrector_horiz_150.jpg

Large (820 K) ftp://ftp.aao.gov.au/pub/local/will/what/what_corrector_horiz3.jpg This is a nearly flat, steerable reflector. It receives the light from the sky and directs it onto the telescope's primary mirror. Credit: Andrew McGrath, AAO

Animation (17 MB avi file) ftp://ftp.aao.gov.au/pub/local/will/what/what-spie.avi Credit: Andrew McGrath, AAO

REFERENCE

Lawrence J. S., Ashley M. C. B., Tokovinin A. & Travouillon T. Nature, 431. 278 - 281 (2004).