Highest ice dome on the Antarctic Plateau best place to view stars

By Australian Geographic 30 July 2020
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A chilly, but superb place to observe stars.

NEW RESEARCH from Australian and Chinese scientists has confirmed that the highest ice dome on the Antarctic Plateau, known as Dome A, is the best place to stargaze on Earth.

In research published today in Nature, scientists demonstrated that conditions at Dome A prevented the obstructive twinkle of stars, caused by turbulence in the Earth’s atmosphere.

“After a decade of indirect evidence and theoretical reasoning, we finally have direct observational proof of the extraordinarily good conditions at Dome A,” says Professor Michael Ashley, an astronomer with UNSW’s School of Physics who was part of the research team.

“Dome A is the highest point in the central plateau region of Antarctica, and the atmosphere is extremely stable here, much more so than anywhere else on Earth. The result is that the twinkling of the stars is greatly reduced, and the star images are much sharper and brighter.”

Related: Why we need to reconnect with the night sky

However, Dome A isn’t completely free of turbulence. “There is this very slow wind that blows across the plateau which is so smooth that it doesn’t generate much turbulence,” Ashley says.

“What little turbulence there is we see restricted to a very low ‘boundary layer’ – the area between the ice and the rest of the atmosphere.

“We measured the boundary layer thickness at Dome A using a radar technique about a decade ago and it’s about 14 meters, on average, but it fluctuates – it goes down to almost nothing, and it goes up to maybe 30 metres.”

The team of researchers set up their telescope on an 8m platform where it protruded beyond the boundary layer, but getting the images was no small feat.

“It was very difficult because the observations have to be made in mid-winter with no humans present,” Ashley says. “UNSW played a crucial role in designing and building the infrastructure that was used – the power supply system, computers, satellite communications – which was managed by remote control.”

According to Ashley, setting up a large telescope in the area would make a large contribution to space research. “Dome A is a superb site for astronomical observations, and we should make every effort to participate in an international project to put a large telescope there to take advantage of the conditions,” he says.

“With Antarctica being so close to Australia, it is a tremendous opportunity.”