‘It’s such an Aussie story’: celebrating 100 years of Mount Stromlo Observatory

Professor Brian Schmidt was an undergraduate at the University of Arizona when he first learned of the Mount Stromlo Observatory. 

During his degree, Schmidt encountered graduate students who had completed their PhDs under the supervision of renowned Australian astronomer Ken Freeman. The scholars’ tales of an observatory on the other side of the world left stars in a young Schmidt’s eyes.  

“It was described as this place of milk and honey,” Schmidt told ABC journalist Annabel Crabb at an event held at The Australian National University to celebrate the Observatory’s centenary.   

“I always thought ‘I wonder what that Mount Stromlo place is like. I’ve gotta get there.’ I felt like it was going to be green and look like Ireland.” 

While the observatory site is far from verdant, inaugural observatory director Walter Geoffrey Duffield still described it as a dream, one “set high among the rocks and lizards and miles from anywhere”.  

In the early 1900s, there was a global project to study the sun. Observatories in India, the US and the UK were all involved, but the researchers wanted to be able to track the sun every minute of the day. This meant they needed a site in the Southern Hemisphere. 

Duffield, an Adelaide-born astronomer, lobbied the Australian government to participate in the project.  

“There was this big gap in our latitude and longitude where nothing could be observed,” Schmidt said.  

“And so, Australia was the place to put an observatory so we could see the sun 24/7 as the Earth rotates.”  

Telescopes, trees and turmoil

Although the Commonwealth Solar Observatory was founded in 1924, the first building on Mount Stromlo was actually the Oddie Telescope, which was established in 1911. It was the first Commonwealth building in in the area, two years before Canberra was named as Australia’s capital. 

But before further progress could be made on the Observatory, the First World War began, which “slowed things right down,” according to Schmidt. 

In 1915, horticulturalist Charles Weston planted hundreds of hectares of pine trees around the Observatory site. 

“All those Monterey pines were planted not for forestry but to cool the mountain and make it suitable for astronomy,” Schmidt said.  

The intention behind the planting was for the trees to absorb heat, prevent turbulence over the mountain and improve image quality for astronomers. Almost 90 years later, the abundance of highly flammable pine trees contributed to the catastrophic damage the Observatory experienced in the 2003 Canberra firestorm.  

Five years after the Observatory was established, Duffield caught the flu during an especially cold winter. The mountain road was blocked by snow, which meant he was unable to make it to the hospital. After he died, he was buried on a ridge close to the Oddie Dome.  

“This whole story is just bizarrely punctuated by wars, by influenza and terrible illness, fire and lots of bureaucratic complication,” Crabb quipped as she and Schmidt talked through the Observatory’s history and the assortment of colourful characters who made it all possible.  

“I love it, it’s such an Aussie story.” 

Wartime efforts

Duffield’s ambition was for the Observatory to take its place among the greatest in the world.  

But during the Second World War, the Observatory pivoted from being an astronomical research hub to an optical munitions factory supplying Australian armed forces.  

“Physicists were one of the only professions not allowed to serve in the military,” Schmidt said. 

More than 25,000 devices – including rangefinders and sights for anti-tank guns – were developed and tested at Mount Stromlo before being distributed to the ANZACs. This detour helped the site’s team to grow from around a dozen to more than 70. 

English astronomer Richard van der Riet Woolley was the director during this industrious period. After the war, the engineers and astronomers turned their sights to the skies once more. 

“When World War Two ended, [Woolley] was ready to go on astronomy straight out of the gate,” Schmidt explained.  

“He really got the infrastructure in place. We went from being isolated to one of the most heavily telescoped observatories in the world.”  

Dazzling discoveries

Mount Stromlo Observatory and its intrepid astronomers, engineers and technical staff have been instrumental in developing our collective understanding of the universe. 

In the 1930s, Clabon Allen’s analysis of the dark lines that cross the sun’s spectrum helped us to understand what makes up the sun’s atmosphere.  

Using the Reynolds telescope in the 1950s, Professor Ben Gascoigne discovered that the universe was double the size and age of what had previously been thought.  

Professor Ken Freeman was one of the first to suggest the presence of an invisible mass in the universe, now known as dark matter. The team that created the very first 3D map of the universe was led by Stromlo academic, Professor Matthew Colless.  

Schmidt himself was at Stromlo when he published research showing that the universe was expanding at an accelerating rate. This observation also led to the discovery of dark energy. It was this research which saw Schmidt named as joint winner of the 2011 Nobel Prize for physics.  

When asked by Crabb about the research opportunities he was most excited about tackling in the future, Schmidt struggled to choose.  

“I look at exploding stars – we can look at them and know exactly what they’ve done. They’re really quite easy to observe,” he said. 

“We also have these big telescopes that look to the edge of the universe. We’re seeing black holes merge; we don’t know why there’s so many black holes. And we’re able to see potential signs of life using these giant telescopes. 

“There are so many things. You’ve just got to choose one. You can’t do it all.”