50 years and counting

Saturday November 05, 2011 Written by luke

While most of us were blissfully unaware of the existence of the Parkes radio telescope until the release of that 2000 film, The Dish, this venerable 64m wide metallic hemisphere has been purring along at the forefront of Australian astronomy for exactly half a century.

Yet another fringe benefit from the six year horror-fest that was World War II, back in the '50s radio telescopy was the great new hope of the astronomical world. Radio telescopes worked by reading the radio wavelengths emitted by cold hydrogen gas, allowing observatories such as Parkes to produce comprehensive images of the hitherto unseen nooks and crannies of galactic structure.

When it was opened on the October 31 in 1961, the Parkes telescope stood as one of the most powerful arrays in the world – so much so that it was the chief antenna used to receive images from the 1969 moon landing. In later years (as its sensitivity was casually jacked up by a factor of 10 000) the telescope played a pivotal role in the discovery of quasars ('quasi-stellar objects') and pulsars ('pulsating star'). At one point Parkes even held the record for identifying the most distant object in the universe, a quasar called PKS 2000-330, floating a cosy 12 billion light years away.

Although the intervening 50 years have seen an explosion in the number and strength of antenna arrays dotting the Earth, Parkes is still ranked third in the world in terms of published discoveries. So, on the occasion of its 50th birthday, we cordially wish it another 50 years of dutiful service and the exalted honour of making first contact with our alien overlords. Transmission ends.

Image: David McClenaghan