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Fraser
2005-Apr-08, 04:43 PM
SUMMARY: If you think current telescopes are powerful, just you wait. A new class of observatories are in the works that could sport mirrors as large as 100 metres (328 feet) across, and have 40 times the observing power of the Hubble Space Telescope. A new study developed by a commission of European astronomers proposes that instruments this large could be built for approximately 1 billion Euros and take 10-15 years to construct.

View full article (http://www.universetoday.com/am/publish/big_observatories_coming.html)

What do you think about this story? Post your comments below.

antoniseb
2005-Apr-08, 05:21 PM
I had read in the study for the OWL (Over Whelmingly Large Telescope) that it looked like the current technological/cost limit for a giant Earth based adaptive optics optical telescope started today would be about 160 meter diameter main mirror.

Such a telescope would have a resolution about half a milliarcsecond. This would be enough to get a moderate resolution image of the face of Pluto, and of several of the larger asteroids.

Guest_Phil
2005-Apr-08, 08:25 PM
[B][SIZE=7][FONT=Arial] :D
I am happy to see that there is still going to be a way to even further in to the unknown. I would have rather like to here about money going in to space telescopes instead, at least upgrade the ones we have already there in space.
We should be pouring the bucks to telesopes if there is not to be maned flights to unknown space. I like to see this happen too. We should just start the jorney Now.

antoniseb
2005-Apr-08, 08:52 PM
Originally posted by Guest_Phil@Apr 8 2005, 08:25 PM
I would have rather like to here about money going in to space telescopes instead, at least upgrade the ones we have already there in space.
It is interesting that this telescope would have 40 times the angular resolution of Hubble, 1500 times the light gathering power of Hubble, be capable of working almost the entire spectral range of Hubble, and yet cost about half of what it originally cost to build and launch Hubble. It is hard to justify building another 2.5 meter Hubble Space Telescope when for the same money you could get two of these 100 meter telescopes.

Greg
2005-Apr-09, 12:44 AM
I agree with that statement. The way I look at it, the ground based telescopes have the potential to outshine (forgive the pun) space based telescopes in the near future (say perhaps the next 20 years at least.) The reason is that the payload cost for something massive enough to beat the ground based telescopes is prohibitively expensive to build considering our currently limited lift capacity compared to the mass of the telescope required. Things that could change that would be a cheaper lift cost such as provided by a space elevator or minituarization of components of the telescope to make it lightweight enough to be lifted into space with our current systems and still surpass the next generation of ground based scopes. Building a larger telescope on the far side of the moon or at its poles wit serial small launches of to-be-assembled parts would be one approach. Single pre-assembled devices such as the hubble, even with the latest technology, would still pale in comparison to what si coming.

Don Alexander
2005-Apr-09, 03:07 PM
The problem with space based observatories today is not so much the mass but the mirror dimensions. You can't build a rocket that can harbor an 8 meter monolithic mirror. Segmented mirrors are a solution, and, if I remeber correctly, JWST will have an unfolding segmented mirror - but of course the unfolding mechanism must be extremely precise to avoid misalignements.

Orbital manufacturing will be the long-term way to go, but that is quite long term...

David Alexander Kann
PhD student, Gamma-Ray Burst Afterglow Collaboration at ESO
Thueringer Landessternwarte Tautenburg, Germany

dave_f
2005-Apr-10, 09:49 PM
One thing I don't see mentioned is: Hey we have an existing space station. It was put up there for science; why not attach an easily-serviceable moderate-resolution camera telescope out there. Nothing fancy.

Just a thought. :ph34r:

filrabat
2005-Apr-10, 11:54 PM
What about atmospheric disturbances? Wouldn't that reduce the value of the information received? I can't see how they can pick up extrasolar planets with that thing (I assume this thing is going to be ground-based).

antoniseb
2005-Apr-11, 12:36 AM
Originally posted by filrabat@Apr 10 2005, 11:54 PM
What about atmospheric disturbances?
Adaptive Optics are used to compensate for the atmospheric disturbances, and are now good enough to work almost perfectly (that is, produce diffraction limited seeing most of the time).

wstevenbrown
2005-Apr-11, 01:01 AM
*Sigh* Weather. Atmospheric turbulence. Atmospheric extinction. 140 degree horizon. Light pollution. Dust. Terrorists. Aircraft lights. Birds/effluvia. Insects/effluvia. <_<

Greg
2005-Apr-11, 01:11 AM
Even with Hubble&#39;s upgrades it would still not be as good as the ground based telescopes. Like it or not shuttle missions are infequent and very expensive. There are alot better things we can spend this precious resource on. This reminds me of my original point that to put together a large enough space telescope to compete with the next genertion of ground based scopes would require numerous shuttle missions with an enormous price tag. Before the era of adaptive optics it would have been worth it, now it is not. I lke the idea of rocketing components to the moon for assembly of a remotely operated telescope there. But that might not even happen in my lifetime.

Guest
2005-Apr-11, 11:52 AM
Originally posted by wstevenbrown@Apr 11 2005, 01:01 AM
*Sigh* Weather. Atmospheric turbulence. Atmospheric extinction. 140 degree horizon. Light pollution. Dust. Terrorists. Aircraft lights. Birds/effluvia. Insects/effluvia. <_<
Plus the fact that our atmosphere limits many wavelenghts such as us missing out in gamma rays, much of Infrared, lost some microwave, our atmosphere is also opaque to UV so we are missing a whole lot of our Ultra Violet, Cosmic waves, X-rays...


There have been some fantastic space telescopes and space observatories that have done stuff which could have never been seen on our Earth, missions like Compton , Hubble, ISO, SOHO, IUE, Spitzer, XEUS, Chandra, Gaia, JWST and TPF, Darwin simply could not be done and will not be from Earth, so if you don&#39;t want the other wavelenghts and don&#39;t desire to do a study of other specturm then stick to the pretty pictures from ground based scopes.

Anyhow I still wouldn&#39;t say no to the huge OWL or ELTs, they are great ideas
because fantastic info can be collected using the ELT visible and these telescopes will provide some of the greatest images yet to be seen, very pretty pics

but comparing ground scopes to Space Observatories is not really do-able

antoniseb
2005-Apr-11, 12:45 PM
Originally posted by Guest@Apr 11 2005, 11:52 AM
our atmosphere limits many wavelenghts such as us missing out in gamma rays, much of Infrared, lost some microwave, our atmosphere is also opaque to UV so we are missing a whole lot of our Ultra Violet, Cosmic waves, X-rays...
Hubble doesn&#39;t detect most of these. Along with optical, it gets near IR and near UV. No one here has made the argument that the Xray, IR, and Gamma Ray instruments should ALSO be earth based.