Radical Antarctic telescope could outdo Hubble (Forwarded)

Anglo-Australian Observatory
Epping, Australias

For more information:

Dr Will Saunders, Anglo-Australian Observatory
Tel: 02-9372-4853 (office)
Email:

Ms Helen Sim, Media Liaison Officer, Anglo-Australian Observatory
Tel: 02-9372-4251 (office) 0419-635-905 (mob)
Email:

Embargoed until 0300 (AEST) Thursday 16 September 2004

Radical Antarctic telescope could outdo Hubble

A novel Antarctic telescope with 16-m diameter mirrors would far outperform the
Hubble Space Telescope, and could be built at a tiny fraction of its cost, says
a scientist from the Anglo-Australian Observatory in Sydney.

"Building an Antarctic telescope could allow Australia to lead the world in
astronomy", said Dr Will Saunders.

Tests by a team from the University of NSW, reported in 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 Saunders.

At an international 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 five times as much.

"With this simple telescope you could do the exquisite imaging that the
'extremely large telescopes' plan to do," 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 and animation

[Image 1:
http://www.aao.gov.au/press/images/w...iew_horiz.jpg]
Overview of the telescope concept

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

[Image 2:
http://www.aao.gov.au/press/images/w...tor_horiz.jpg]
Telescope corrector

This is a 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:
ftp://ftp.aao.gov.au/pub/local/ajm/what/what-spie.avi (17MB)]
Credit: Andrew McGrath, AAO