View Earth’s clearest skies from Antarctic plateau, say scientists

June 8th, 2009 - 3:06 pm ICT by ANI  

London, June 8 (ANI): A research team has found that the Antarctic plateau offers world-beating atmospheric conditions to view possibly the clearest skies on Earth.

According to a report in New Scientist, Michael Ashley of the University of New South Wales in Sydney, Australia, and his colleagues wanted to find the best sites for astronomy on the Antarctic plateau.

Combining observations from satellites and ground stations with climate models, they evaluated different factors that affect telescope vision, such as the amount of water vapour, wind speeds and atmospheric turbulence.

The team found that the plateau offers world-beating atmospheric conditions, as long as telescopes are raised above its frozen surface.

The ice makes the lowest layers of air on the plateau much colder than those above, forming an “inversion layer” that, together with the strong local winds, can lead to severe turbulence. This would blur a telescope’s images.

The team’s analysis showed the inversion layer is only about 20 metres thick, however.

“If a telescope was mounted above it, its view would be affected by far less turbulence than at other world-class observatory sites,” said Ashley.

“It’s drier than Mauna Kea (in Hawaii) by a long way and drier than the Atacama desert (in Chile),” he added.

Such conditions would be good for studying star birth.

Normally, water vapour in the atmosphere blocks telltale emissions from molecular clouds in star-forming regions of the Milky Way.

But, the air above the high area known as Dome A is so dry that a ground-based telescope there could observe stellar nurseries, which is something that’s impossible anywhere else on Earth.

So far as Ashley’s team know, Dome A seems the best site for astronomy.

China has already built a summer station there, with a small robotic observatory. Next best is Dome F, the site of a Japanese station. (ANI)

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