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Comet hunters warn of threat to Siding Spring Observatory

Jenny Winder, News Writer
Nov 6, 2014, 5:45 UTC

Sen—Astronomers fear that a major Australian optical observatory, that has become as famous for comet discoveries as its other research, is under threat from gas prospectors.

Siding Spring Observatory, in New South Wales, has been the home of several comet hunters, including Robert McNaught who holds the world record for the number of finds. These total 82 discoveries under his own name and more under the name of the observatory.

They include C/2013 A1 Siding Spring, the comet that had a close brush with Mars last month, and Comet McNaught (C/2006 P1) which dazzled southern hemisphere observers in January 2007.

Fellow astronomer Malcolm Hartley’s finds have included Comet 103P/Hartley in 1986, which became famous when visited by NASA’s EPOXI/Deep Impact spaceprobe in 2010.

Now the two men are supporting a campaign against plans by gas mining company Santos to develop industrial scale coal seam gas (CSG) mining in the region. Their bid to publicise their opposition has included adding slogans to models of planets that form a local model of the Solar System.

The two are backed by four other comet discoverers who have worked at Siding Spring—Steve Lee, Donna Burton, Trish Watson and Gordon Garradd.


Comet discoverers protest gas mining plans. Image credit: Robert H. McNaught, artwork by Laura Hartley and Di Bedggood

The astronomers say that even three gasfields about 50km away from the observatory, proposed by Santos, will produce light pollution that will destroy their pristine dark skies by producing more glow than nearby towns, due to flares burning off gas, as well as security and operational lamps.

They also fear that airborne dust and industrial contaminants will increase the level of light pollution and also have a detrimental effect on telescope optics.

The observatory lies in the Warrumbungle National Park on Mount Woorat, near Coonabarabran, New South Wales. It is part of the Research School of Astronomy and Astrophysics (RSAA) at the Australian National University (ANU) and is home to 12 Australian and International telescopes.

One is the 3.9-meter Anglo-Australian Telescope (AAT) which was jointly run for many years by the UK and Australia before the UK pulled out in 2010.

The 9,000 hectare (90 sq km) area includes grazing, rural living, tourism, bushland, private conservation, productive gardens, observatories, Aboriginal cultural sites, springs, creeks and good groundwater.

In January 2013, the observatory narrowly escaped a savage bushfire that swept through the area, but some outlying buildings, including McNaught’s own home were destroyed in the blaze.

The campaigners say that an overwhelming 92 per cent of the local Timor Valley community oppose the expansion of the CSG industry into the area. Residents are concerned about water quality and health issues. They say they do not have confidence that mining companies or government bodies will openly disclose potential and actual threats from their activities.

McNaught commented: “To put at risk the world class status of Siding Spring Observatory is both illogical and galling. “It’s also infuriating that community concerns are being trampled upon by both government and industry.”

Santos is one of Australia’s largest producers of gas to the domestic market and has the largest exploration and production acreage position in Australia of any company. It holds a Petroleum Exploration Licence over a wide area around Coonabarabran.

A spokesman for the company said that a survey was being carried out to examine the environmental impact of its work and that interested parties would be consulted.

Another blow to the observatory has been the removal of funding last year for a survey of southern skies for near-earth objects (NEOs) including potentially hazardous asteroids and comets that might one day hit the Earth.

McNaught, who performed the service before it ended, told Sen: “The Siding Spring Survey closed at the end of July 2013 for the want of a single salary. There is now no systematic NEO survey in the southern hemisphere. Absurd.”

Siding Spring Observatory—Eyes on the Sky. Credit: RSAA ANU