Bright Lights Put Astronomers In The Dark

The telescope is a joint project between the Universities of Adelaide and Tokyo. CANGAROO stands for the Collaboration of Australia and Nippon for a GAmma Ray Observatory in the Outback. The Japanese have provided most of the $4 million required to build it , while Australia provides its Woomera setting and manages the day-to-day running of the telescope.

Cangaroo II was officially opened on May 9 as part of National Science Week. Two weeks later, 6o guests at a reception in the Australian embassy in Tokyo were shown a video of the launch, which received international media coverage.

Woomera is an ideal location for astronomy, as the skies are mostly clear, and the siting of the telescope near the old rocket range places it far enough from the town for lights not to be a problem.

Or it did, until the old military camp was upgraded to become the new detention centre for illegal immigrants. Powerful floodlights now ring the centre’s perimeter. From a distance, it squats on the horizon like a small city, its lights corrupting the observations of astronomers who have come here to escape light of almost any kind.

‘The problem with the lights is that we are looking at very faint flashes of light from the upper atmosphere which are produced by the gamma rays that we’re searching for,’ said Dr John Patterson, Adelaide University astrophysicist and the Australian co-ordinator of the project. ‘These flashes are so faint, and the telescope is so sensitive, that even a firefly flying across the front of the telescope would be a problem to us,’ he said.

It is not just the astronomers who are dazzled. Air Force and Flying Doctor planes that must approach the airport at night from the north or take off to the south can also find the lights a problem.

It is a potential economic problem, too. Cangaroo II is intended to be the first of four such telescopes, erected 100 metres apart and linked together as Cangaroo III. Funding, again from Japan, will be $16 million, but the program will be reviewed after the construction of the second telescope. Failure to solve the light problem could set the rest of the exercise at risk.

Light astronomy could suffer the same fate. The Global Telescope Network does astronomy online. The Colorado-based company is placing hundreds of telescopes around the earth at strategic locations, to be used by anyone with a modem and a computer. Via the internet (www.globaltelescope.com), astronomers can book time on the research grade instruments to study and photograph astronomical phenomena from anywhere on the globe The company is interested in Woomera as its first southern hemisphere site.

‘They are looking to establish a pilot installation with several automatically controlled telescopes,’ said Dr Patterson. “The site is pretty remote, so the option of using optic fibre cable with a very high data rate is probably not cost effective, ‘ he says, ‘so this pilot arrangement may use a satellite link to send images to the United States.’

For all these 21st Century technologies to co-exist, Woomera needs to get back to the dark ages, and the area administrator, Joe van Homelen is keen to oblige. He has plans to fix the detention lights as soon as he can.

‘We need to change the brightness of the lights, change the angle of the lights and then erect a barrier for the lights,’ said Mr van Homelen. ‘The issue really is to make sure that everyone can do their particular business without interference and with co-operation,’ he said.

Woomera’s role in space science has seen it serve as a rocket range, a proving ground, and a satellite tracking station. While there are plans for future rocket launches, these are so far on a minor scale, and Woomera faces an uncertain future.

Getting a focus on the light problem may well see the town begin a new chapter in space science; as an international centre for astronomy of many kinds.

Photos of the Cangaroo II gamma ray telescope available at:http://www.adelaide.edu.au/PR/media_photos/

Contact:

Dr John Patterson -- ph: (618) 8303 5291, (618) 8303 5996; email: jpatters@physics.adelaide.edu.au

Dr Rob Morrison, Adelaide University Media Unit -- ph: (618) 8303 3490; email rob.morrison@adelaide.edu.au