Chile Poised to Host Biggest Telescope in the World

Chile Poised to Host Biggest Telescope in the World
The largest astronomical instrument in the world, the European Extremely
Large Telescope (E-ELT), will likely be built at Cerro Armazones in
northern Chile, the European Southern Observatory (ESO) announced...

http://news.sciencemag.org/sciencein...t-te.html?etoc

On Mar 4, 9:37*pm, Sam Wormley wrote:
Chile Poised to Host Biggest Telescope in the World

You know, never mind earthquakes, I would have thought that questions
of political stability would lead to the world's largest telescopes
being in Australia.

But then I realized that, while Australia is dry, and does have
mountains, they're in the wetter parts of the country, while Chile has
higher mountains near its few deserts - such as the famed Atacama
desert. So, naturally, the biggest telescopes go where the best sites
are.

John Savard

On Mar 5, 1:12*am, Quadibloc wrote:
On Mar 4, 9:37*pm, Sam Wormley wrote:

Chile Poised to Host Biggest Telescope in the World

You know, never mind earthquakes, I would have thought that questions
of political stability would lead to the world's largest telescopes
being in Australia.

Australia's largest telescope, though, is no slouch: the 3.9 meter (or
150 inch) Anglo-Australian Telescope. Still, given the popularity of
the Southern Hemisphere, I would have expected that by now they'd have
something bigger than Palomar... at least one 8 meter instrument. But
if there are no _really_ good sites left there, I suppose it's
understandable.

John Savard

"Dan Birchall" wrote in message
...
(Quadibloc) wrote:
On Mar 5, 1:12 am, Quadibloc wrote:
On Mar 4, 9:37 pm, Sam Wormley wrote:

Chile Poised to Host Biggest Telescope in the World

You know, never mind earthquakes, I would have thought that questions
of political stability would lead to the world's largest telescopes
being in Australia.

Australia's largest telescope, though, is no slouch: the 3.9 meter (or
150 inch) Anglo-Australian Telescope. Still, given the popularity of
the Southern Hemisphere, I would have expected that by now they'd have
something bigger than Palomar... at least one 8 meter instrument. But
if there are no _really_ good sites left there, I suppose it's
understandable.

I think it's really an elevation thing. The highest elevation in
Australia is 2230 meters, while the Canaries are around 2400 meters,
scopes in Chile *start* around 2200 meters and go up to more than
2700 meters (not even counting the submillimeter projects at Atacama
which are at something crazy like 5000 meters) and of course Mauna
Kea's observatories are around 4100-4200 meters.

The lower the scope is, the more atmosphere and atmospheric water
vapor it gets stuck looking through, so "high and dry" is the motto.
As far as I know, every optical imaging scope larger than 6 meters
with a fully-movable mount is sited higher than Australia's highest
summit.


Unfortunately true.

There is another problem - Australia's "mountains" are on the east side of
the continent. Good sites have lots of ocean to the west to increase
atmospheric laminar flow. Wind is not the problem, the problem is changes in
wind speed.

Although I love optical astronomy, and am a proud Australian, I have to
admit that Australia does not have the best sites for optical astronomy, and
its not the area we should concentrate in.

We do have the best sites in the world for radio astronomy. Hopefully the
square kilometer array will come to Australia. No other country in the
Southern Hemisphere has anything like the infrastructure and technical
capability that Australia has in this area, and if you are looking for big
open quiet empty places, welcome to the Australian outback.

That we are one third of the earth away from the USA in one direction and
Western Europe in another is another potential advantage we have over both
South America and Africa, the only other major landmasses in the southern
hemisphere.

I would also argue that Australia has easily the best locations for
gravitational wave detectors, as it is the lowest seismic activity of any
continent, and again big open quiet places. However, the apparent failure of
gravitational wave detectors to detect gravity waves has tempered my
enthusiasm for this technology.

On Mar 7, 1:22*am, "Peter Webb"
wrote:

There is another problem - Australia's "mountains" are on the east side of
the continent. Good sites have lots of ocean to the west to increase
atmospheric laminar flow. Wind is not the problem, the problem is changes in
wind speed.

Taking a look at a few maps, I now have a clearer picture of this.
Australia's tallest mountains are not only on the _east_ side of the
continent, but they're in the south, where, indeed, the prevailing
winds blow eastward.

The northern parts of Australia are in the tropics, where the winds
blow westward, but while there are some hills on Australia's west
coast, or around Cairns, yes, if really high mountains are what you
need, even Tasmania isn't going to deliver.

However, Cape York, being on the eastern side of Australia, and close
to the equator, is a much better place to launch rockets from than
Florida.

John Savard

Dan Birchall:
I think it's really an elevation thing. The highest elevation in
Australia is 2230 meters, while the Canaries are around 2400 meters,
scopes in Chile *start* around 2200 meters and go up to more than
2700 meters (not even counting the submillimeter projects at Atacama
which are at something crazy like 5000 meters) and of course Mauna
Kea's observatories are around 4100-4200 meters.

The lower the scope is, the more atmosphere and atmospheric water
vapor it gets stuck looking through, so "high and dry" is the motto.
As far as I know, every optical imaging scope larger than 6 meters
with a fully-movable mount is sited higher than Australia's highest
summit.

Hmmm. That's rather technical, but if I understand you correctly, you
are saying that an elevation of 20 meters surrounded by the marshes of
eastern Maryland is not the _ideal_ location for my little zerbat'ry
http://www.primordial-light.com/observatory.html.

Davoud

--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.

usenet *at* davidillig dawt cawm

On Mar 6, 11:09*pm, Dan Birchall
wrote:
(not even counting the submillimeter projects at Atacama
which are at something crazy like 5000 meters)

If one is concerned about the political situation in Chile, however, I
have found a 5000 meter elevation in the Southern Hemisphere in a
place that should be as peaceful as Australia. There is the minor
problem of reduced access to stars in the Northern Hemisphere - and
the more major one of inclement weather.

Vinson Massif is _high_ enough for a major telescope, even if the
notion of siting a major observatory in Antarctica qualifies as
impossibly impractical.

John Savard