The Murchison Widfield Array in Western Australia is situated far away from radio signals that could overpower the weak whispers it is receiving from space.
Credit: Paul Bourke and Jonathan Knispel. Supported by WASP (UWA), iVEC, ICRAR, and CSIRO
SYDNEY: A new radio telescope that could help researchers peer into the origins of the universe is moving forward after the completion of a protective enclosure that will shield sensitive electronic receivers from dust and heat.
The Murchison Widefield Array (MWA) telescope is based in the outback of Western Australia, and once finalised will allow astronomers to gaze into the far-reaches of space to see how stars and galaxies were formed billions of years ago. It’s an ideal location for viewing the cosmos because of its isolation, but one that presents a variety of obstacles.
“You have very sensitive and high performance electronics and a very harsh climate in which to operate,” said Steven Tingay, a professor of radio astronomy at Curtin University who works on the MWA project. “These electronics need to be packaged into a unit that can sit out in the ground in the desert, and be able to survive extreme temperature and weather variables such as rain, dryness and dust.”
Keeping the environment interference free
But this is only half the battle. The new cases do more than shield the electronics from external dangers; they also contain the radiation emitted by these instruments so they do not cause interference in an otherwise ‘radio-quiet’ environment.
“The reason we go to a location like this is because there’s very little man-made interference from things such as mobile phones, radio and television stations,” said Tingay. “It’s very important that whatever we build up there maintains the pristine environment that currently exists.”
Located at the Murchison Radioastronomy Observatory (MRO), about 500 km northeast of Perth, the MWA is optimally situated in a vast expanse of flat open space that is virtually free of human activity. The Shire of Murchison has an area of roughly 50,000 square km – larger than many European countries – and an estimated population of only 150 people.
How the MWA works
When fully completed the telescope will have roughly 500 antennas, which receive radio signals from outer space, and 64 encased receivers, which will convert these signals into digital data.
This data is then transferred via optical fibres to a processing facility where the signals from all 500 antennas are processed simultaneously to recreate an image of the sky – an image that can quite literally take researchers back in time.
“It’s astounding you can even do this,” marvelled Tingay. “It’s mind blowing even for astronomers who are working in the field – the fact that you can build something on the ground and observe something happening billions of years ago. It’s pretty wild.”
Tingay said there is still a lot of work to be done, but hopes the system is fully operational by the self-imposed deadline of August 2012, a deadline that will enable researchers to view a region of the sky that has as a limited window of opportunity.
Precursor to further exploration
The MWA telescope is one of three precursors to the Square Kilometre Array (SKA) project – an AU$2.5 billion collaboration between institutions across 20 countries, including Australia and New Zealand. Once developed it will be the world’s largest and most advanced radio telescope and the MRO site is one of two potential candidates. The other potential site is in South Africa.
Australia is also home to another precursor – the Australian Square Kilometre Array Pathfinder (ASKAP), which is also based at the MRO site and uses slightly higher radio frequencies to observe the sky. There have been six 12-metre antennas constructed to date, with another 30 to be completed by the end of 2011.
Anne Green, a physics professor at the University of Sydney who is working closely with ASKAP said the work being done on the MWA telescope is paving the way for the SKA project and helping to prove that Western Australia is an ideal location.
“Before we start to design for the SKA we need to be pushing the boundaries and this is what the MWA is doing,” said Green. “They’re showing how to transport and analyse vast amounts of data, and proving the viability of the site by showing you can have high-performance electronics working robustly in a harsh environment.”
