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100 Meter OWL Telescope Project
mindpixel writes: "The European South Observatory (my employer) is getting VERY serious about building the OWL (OverWhelmingly Large) 100 meter telescope. Check out this new site dedicated to the project. You can see some cool diagrams of what the OWL telescope will look like and some simulated images here." For more about telescopes of unusual size, you might read McKinstry's interview last year.
Nope. Un uh, sorry, these bad boys are talking about one solid 100-meter MIRROR with a telescope assembly that would just fit under the Gateway Arch in St. Louis and stand almost 3/4 as tall.
To put that in perspective, once the thing's built, you would have a good chance of seeing it on the horizon with your naked eye from 15-20 miles away (a rough guess, I know).
You know that gargantuan telescope Marvin the Martian had in the Bugs Bunny cartoons? The OWL makes it look like a Cracker Jack prize.
He put his boots up on the table and made a face. "The sig," he smirked. "You can waste your life in search of the sig."
For the price of one small space telescope (HST mirror is only 2.4m in diameter) you can build the largest earth-based telescopes ten times over (the ESO VLT, 4 8m telescopes working as an array will, when fully operational in 2003-2004 have cost maybe 1/5 of what Hubble has cost until now). Furthermore, in visible light, earth-based telescopes are already producing images as sharp as, and even sharper than Hubble. At the time the HST was conceived, Adaptive Optics, which can eliminate most atmospheric turbulence, was still a US Military classified technology). The only short-term reasons for building space telescopes are: 1) observing in wavelengths absorbed by our atmosphere (like much of the IR and UV spectrum) 2) Getting spectra of earth-like planets surrounding other stars, this would require a space-based interferometer, because the earth probably isn't a sufficiently stable base to do this type of observations...
What are the benefits of having an Earth-bound, optical telescope? Or rather, what can a larger optical telescope find better from Earth that we can't already find on other wavelengths and from other venues (i.e. The Hubble)?
If there are no advantages here, is it more cost-effective, or what?
Chris: What you should actually ask is what advantage does a space based telescope have over a ground based telescope? The only thing you gain from being in space for an optical telescope is better image quality due to lack of atmospheric turbulence. By for every other measure (maintenance, support, materials, etc.) being in space is much, much more expensive and limited. Which is why the Hubble and it's 2.4 meter primary cost a number of times more than the projected cost of of the 100 meter OWL. Recent advances in computer technology (adaptive and active optics) have greatly reduced the advantage that being in space provides at optical wavelengths. For some non-optical telescopes (x-ray, IR, gamma ray) there will always be an advantage to being in orbit.
Super expensive, since the dark side of the moon is constantly rotating around the moon. You would need a railway system which was circum-lunar, and then you would drive the telescope around the moon every 28.xx days. During New Moons, the telescope would be facing Earth. There is no "dark" side of the moon that stays dark. There is a "far" side of the moon that never faces Earth, but it can no more be considered dark than any other part of the moon.
On the other hand, it is far away relative to low Earth orbit. It is expensive to get there and, once there, manned missions to repair and upgrade it would be, at this time, out of the question. Hubble has benefitted massively from such upgrades, from the optics correction package to the replaced gyros and computer upgrade. You could do without them, but it's something to be considered.