Home Radio waves Australia’s first “dark sky park” attracts astronomers

Australia’s first “dark sky park” attracts astronomers



SYDNEY, Australia – Gaze in wonder at the stars has been part of the human experience since the dawn of time, and on a frigid night in Australia there is perhaps no better place to do it than in the Range of Warrumbungle Mountains 400 km northwest of Sydney.

From an icy vantage point among the jagged peaks of the Warrumbungles, where the only light comes from a rising moon, the majestic Milky Way galaxy stretches across the dark southern hemisphere sky. Billions of stars sparkle in this vortex of gas and dust, part of a greater vastness that we know simply as the universe.

With its lack of intrusive artificial light, the pristine viewing environment of the Warrumbungles attracts professional and amateur astronomers – so much so that the nearby town of Coonabarabran bills itself as “the astronomical capital of Australia” and l ‘International Dark Sky based in the United States. The association has named Warrumbungle National Park as Australia’s only “dark sky park”.

For more than 40 years, the park has been home to Australia’s largest optical telescope, the 3.9-meter Anglo-Australian Telescope at Siding Spring Observatory, operated by astronomers from the Australian National University and others. scientific institutes. On the fringes of the national park, private observatories have sprung up to respond to what is now a global tourist niche known as “starry sky travel” or “astrotourism”.

The COVID-19 pandemic may have cooled the international side of this travel industry, but domestic visitors are taking over. Australian starry sky travel pioneer Marnie Ogg says even with COVID-19 restrictions, observatories around the world are thriving. “Sales of telescopes have exploded,” she told Nikkei Asia. “The night sky is something that cannot be taken away from people. Even if you cannot travel, you can still go out at night and look at the sky.”

Marnie Ogg, Australian pioneer of starry sky travel, founder of the Australasian Dark Sky Alliance. (Courtesy of Dianne Ogg)

Ogg runs a Sydney-based company named Dark Sky Traveler and is the founder of the Australasian Dark Sky Alliance, a non-profit organization that works to educate government officials and communities on how to minimize light pollution in the stargazing areas and creating tourism opportunities.

It was instrumental in the recognition of Warrumbungle National Park as a Dark Sky Park in 2016 – the only such park in the southern hemisphere until the designation of Wai-Iti on the South Island of the New Zealand in July of last year.

In total, the International Dark Sky Association, based in Tucson, Arizona, has designated 100 International Dark Sky Parks in the world since 2001, including 75 in the United States, reflecting the interest in stargazing there. low. Japan has two parks, on Kozushima Island about 180 km south of Tokyo, and Iriomote-Ishigaki National Park on the Yaeyama Islands in the East China Sea, about 270 km east of Taiwan.

The night sky filled with stars over the Dark Sky Park in the Warrumbungles. (Courtesy of Destination NSW)

Ogg says that in three decades of running dark sky travel around the world, customer feedback is that Australia remains one of the best places for stargazing. “Our skies are even darker than anywhere else, and Australia is the best place to see the Milky Way.”

Warrumbungle National Park was the obvious candidate for Australia’s first Dark Sky Park, as there was already a lighting policy for the Siding Spring Optical Telescope, and local government authorities and the community were aware of the need to protect the night sky. Ogg says the dark sky park designation was “a rationale for doing things right in terms of outdoor lighting policies.”

Dark, calm skies, crystal clear nights, and relatively high elevation make the Warrumbungle Mountains ideal for astronomical research, using both optical telescopes and radio telescopes. In Siding Spring, at the top of 1,160-meter-high Mount Woorut, scientists operate an optical telescope that uses giant mirrors rather than lenses to capture light, allowing them to record and analyze what the telescope “sees”.

A few miles east of Siding Spring is the 22-meter Mopra Radio Telescope, operated by the Australian government’s scientific research agency CSIRO. In the absence of radio “noise” from them, scientists can connect to the Australia Telescope Compact Array, a mobile set of six 22-meter radio telescopes about 100 km to the north in an equally quiet location outside the United States. town of Narrabri. .

Two of the 22-meter radio telescopes of the Australian Compact Array Telescope, near Narrabri. (Photo by Geoff Hiscock)

The antennas of these telescopes collect radio waves from space and convert them into electrical signals. The combination of these signals allows astronomers to build up a picture of cosmic radio sources.

There are camping sites inside Warrumbungle National Park, and it is possible to visit Siding Spring Observatory during the day, although there is no public access at night other than a weekend in October. Private observatories located just outside the park, such as the Milroy and Warrumbungle Observatories, have smaller telescopes and run tours for visitors to explain what’s going on in the night sky.

At the Warrumbungle Observatory, about a 10-minute drive from Coonabarabran, visitors are guided through a map of the night sky, helping them locate the brightest star, Alpha Centauri, and its twin Beta Centauri in the constellation. of the Centaur. Both are “pointers” to the celestial south pole, in conjunction with their near neighbors, the stars of the constellation Southern Cross, which appears on the Australian national flag.

Stars in the evening sky above the Breadknife rock formation in Warrumbungle National Park. (Courtesy of Destination NSW)

“Warrumbungle” means twisted or broken mountain in the language of the traditional indigenous caretakers of the earth, who have been practicing their own form of astronomical research for thousands of years. The Gamilaroi, Wiradjuri and Wailwan peoples looked up to the sky above the Warrumbungles to guide their spiritual practices and Dreamtime creation stories, to discern practical information such as the seasonal availability of certain foods and to alert them to conditions. meteorological.

Ogg has some handy tips for future astronomers, whether they’re observing in Warrumbungle Dark Sky Park or elsewhere. “You have to give yourself the best chance. Your best opportunity is five days on either side of the new moon, and you have to allow your eyes 20 minutes to adjust to the different light loads. your kitchen well lit and looking at the night sky, you will only see 10 to 15% of what is there. Your pupils have to adapt to the different conditions. “

Ogg adds that while telescopes are a great idea for stargazing, they take a little getting used to and can cost anywhere from $ 300 to $ 100,000. “The easiest way to start is with a pair of binoculars. It’s something most people may already have at home,” she says.