View Full Version : The Clearest Skies on Earth

2006-Jun-21, 05:20 AM
Telescopes are perched at the tops of mountains because the air up there is thinner, drier and clearer than the view from sea level. But the best views of all are near the south pole in Antarctica, in a region called Dome C. With its high altitude, low temperatures, and crystal clear skies, Dome C boasts nearly perfect viewing conditions. A team of French astronomers are hoping to build a trio of telescopes that work together as a single, large telescope as a prototype. But they've got their sights set on a larger installation that could rival the capabilities of the best telescopes on Earth. It's all about location, location, location.

Read the full blog entry (http://www.universetoday.com/2006/06/21/the-clearest-skies-on-earth/)

2006-Jun-21, 12:49 PM
Dome C looks like a great place unless you need to go outside for some reason. Hopefully, we'll get some big instruments built there that can be operated remotely.

2006-Jun-22, 03:14 PM
Ya, a repair mission could be as challenging as repairing Hubble...but at a fraction of the cost.

2006-Aug-20, 01:19 PM
The air in the height of the iceshield of Antarctica is very dry, clear and clean. Nevertheless, you have snowfall at times, and storms of horrible strength and utter coldness. And the ground is not good to build things on. Ice is not solid rock.

Putting an observatory onto ice means that the observatory will move with the ice. Ice is not solid, it flows and gives way if pressed.

Almost all scientific stations located on the ice shield of Antartica tend to be covered by snow fall or sink into the ice, until it pours in, or presses the station until it collapses. Therefore they have to be abandoned with time and have to be replaced by a new one.
You can´t set up the precise alignment of a telescope mount which is required to attain results of some use, if you build it on ice, no matter how thick. It will give way under the load of your construction.



2006-Aug-20, 03:19 PM
You canīt set up the precise alignment of a telescope mount which is required to attain results of some use, if you build it on ice, no matter how thick. It will give way under the load of your construction.

It strikes me that you could build a massive observatory on Dome C, provided that you built the foundation in such a way that it 'floated' on the surface like a barge, displacing as much ice as the whole structure weighs.

2006-Aug-20, 04:42 PM
University of New South Wales: Exceptional astronomical seeing conditions above Dome C in Antarctica (http://www.phys.unsw.edu.au/nature/)

Link to letter published in Nature, 16 September 2004, some pictures, and a long FAQ.

2006-Aug-20, 09:20 PM
Title: A review of optical sky brightness and extinction at Dome C, Antarctica
Authors: Suzanne L. Kenyon, John W. V. Storey (School of Physics, University of New South Wales)

The recent discovery of exceptional seeing conditions at Dome C, Antarctica, raises the possibility of constructing an optical observatory there with unique capabilities. However, little is known from an astronomer's perspective about the optical sky brightness and extinction at Antarctic sites.
Researchers review the contributions to sky brightness at high-latitude sites, and calculate the amount of usable dark time at Dome C. They also explore the implications of the limited sky coverage of high-latitude sites and review optical extinction data from the South Pole.
They also examine the proposal of Baldry and Bland-Hawthorn (2001) to extend the amount of usable dark time through the use of polarising filters.

Read more (http://arxiv.org/PS_cache/astro-ph/pdf/0511/0511510.pdf) (PDF)

<Attachment 1>
Located at 75.6' South, 123.21' East and an altitude of 3250 m, Dome C is the third highest point on the Antarctica Plateau.

Dome A (Dome Argus) is an Antarctic plateau located 1200 kilometres inland. It is thought to be one of the coldest naturally occurring places on Earth, with temperatures believed to reach -90 °C. It is the highest ice feature in Antarctica, comprising a dome or eminence of just over 4,000 m elevation, located near the centre of East Antarctica and approximately midway between the head of Lambert Glacier and the South Pole.
The name "Dome Argus" was given by the Scott Polar Research Institute from Greek mythology; Argus built the ship in which Jason and the Argonauts travelled.

<Attachment 2>
Position: 81°0′S 77°0′E

2006-Aug-24, 03:34 PM
Technically, the location is great, but the South Pole does experience horrible snowstorms that will seriously wreak havoc with the telescope hardware.

A good location would be the Great Australian Bight, where the lack of light pollution and almost no air pollution would make it perfect to locate a large telescope installation.