World's Largest Telescope Up and Running 120
apdyck writes "ITWire is reporting that the world's largest telescope is now up and running, conducting one-year series of tests. The Great Canary Telescope, located in the Canary Islands, is the largest telescope in the world at 10.4 m (34') in diameter. Not for your average stargazer! 'The reflective telescope, sometimes also called GranTeCan, uses technology called adaptive optics, in which the mirror changes its shape in order to correct distortions of light caused by the Earth's atmosphere. The telescope is part of the Observatorio del Roque de los Muchachos, located on the island of La Palma, Spain, within the Atlantic Ocean.'"
Worlds Largest Telescope Up and Running (Score:4, Funny)
Who you gonna call? (Score:4, Funny)
Someone call Pierce Brosnan. Tell him to bring NASA's experimental locator beacon.
Hey (Score:4, Funny)
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http://www.springerlink.com/content/wqw46755050017 61/?p=78e25fed12e247b2865ad85a359ecb45&pi=1 [springerlink.com]
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That's not what your girlfriend told me last night...
(sorry, couldn't resist...)
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Um, no. (Score:2)
Larger aperature also means higher resolution images
iTWire Strikes Again (Score:2, Insightful)
The twins can also be made to work in tandem - as a so-called interferometer - which allows them to mimic a larger telescope that is 85m (279ft) wide.
It's funny how I can submit a story [slashdot.org] only to have it rejected then have it accepted as two different stories the next week.
Re:iTWire Strikes Again (Score:4, Informative)
Now, if you want to talk about genuinely huge telescopes -- the GCT is only slightly bigger than the Kecks, after all -- the planned OWL (Overwhelmingly Large Telescope) [wikipedia.org] is probably what you're looking for.
Re:iTWire Strikes Again (Score:4, Informative)
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I can but dream (Score:2)
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Your condescending "Meades are toys" translates to "stay away from astronomy". If someone is interested in the sky, there's nothing better than for them to buy an inexpensive telescope or a nice pair of binoculars. That's an investment even the most casual of intereste
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Advice from a (sort of) newbie astronomer (Score:5, Informative)
You might be disappointed if you wait a year, buy the more expensive telescope and have no money left over to buy upgrades.
Some other points:
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No argument with most of what you said but I disagree on cheaper scopes if it means a smaller aperture.
With telescopes aperture is everything, the bigger the better. A few quid saved on aperture for some accessories will soon be regretted when you find you should have gone for the light gathering power of an 8'' as opposed to a 6'' or 6'' as opposed to 4''.
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However, if you look at planets or the moon, a small aperture high focal length scope is better than the opposite. I moved to urban sprawl, so I can't view deep sky stuff. My 8" Newt is mostly useless. If I could, I'd trade it i
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I can go with that.
However, if you look at planets or the moon, a small aperture high focal length scope is better than the opposite. I moved to urban sprawl, so I can't view deep sky stuff. My 8" Newt is mostly useless. If I coul
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Department store telescopes are the pits. A good spotting scope is more use, particularly if you're going to be interested in bird watching (the flying kind, not the arrested if ).
Particularly good advice to buy a Dob. 8" to 12". In my opinion 10" is just right, particularly if you have a large car and don't have medical issues that prevent you carrying some weight (but get a trolley anyway!) Much larger than 10-12" and you need a trailer or Van, or you need to get to you need to align you
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You might not want to spend the money on a computerized drive, but you do want some sort of motorized drive so that you don't have to continually reposition the scope. If you're going to do astrophotography, you definitely want a drive.
If you're up for a real challenge, grind your own mirror.
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Why was it unpopular? A couple of reasons:
* Poor quality 1" eyepieces that come with the scope.
* Need an adapter for 1.
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No, it's not the world's largest telescope. (Score:5, Informative)
And then you've got the array telescopes like VLA [nrao.edu] and VLBA [nrao.edu], if you wanted to get pedantic about effective telescope size.
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OTOH, does interferometry(?) count when you're announcing the world's largest optical telescope (as in, singular instrument, which I believe is assumed here)?
Re:No, it's not the world's largest telescope. (Score:4, Informative)
It's still not the largest optical telescope. SALT is 11.1m and is, like GTC, made of an array of mirrors. The LBT is 2x8.4m mirrors for an effective 11.8 aperture. Also "bigger" than GTC.
Sure, the LBT isn't fully functional, but neither is GTC.
SALT is fully operational. SALT is bigger. Article is WRONG.
http://en.wikipedia.org/wiki/List_of_largest_opti
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Re:No, it's not the world's largest telescope. (Score:5, Informative)
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Forgive me to trying to correct the writeup on the site on which it appeared.
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It's Chuck Norris's eyes.
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*much* larger because the wavelenghts are so much larger, so to match their optical cousins
in *resolution*, they need to be bigger (either directly, or through aperture synthesis).
Now, the radio telescopes have much larger sensitivity--they have much larger effective apertures
than any of the optical telescopes we're talking about here. Many interesting astrophysics
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DSP? (Score:2)
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Why do they need to change the shape of the mirror? Why can't they just correct the problem using DSP after the fact? Presumably if you know how the atmosphere distorts while taking the image, you can apply the inverse kernel later on...
Might be for resolution reasons... from an engineering standpoint, it appears to be more feasible to make minute modifications on a big honkin' mirror, than to try and make changes based on what a much smaller CCD picks up off of it.
That and I suspect that it would allow them to use non-digital gear (okay, film) to record with the exact same result of data intake, or to swap out visible CCD's with infrared (w/o the additional expense and duplication, or in calibrating between the two different sensors,
Re:DSP? (Score:5, Informative)
Mod parent's answer up, not mine. (Score:2)
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There are plenty of problems with adaptive optics, however. The folks I work with who work on the LBT say that they've managed to crack four secondaries in a row, with zero intact ones in existence. This is not surprising, given the secondary mir
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The light that forms the image may take hours or even days to accumulate. The distortion is dynamic and will randomly wander about the place during the exposure period, meaning that many pixels will be erroneously "overwritten".
In other words the photons collected by the CCD cannot be used after the fact to "know how the atmosphere distorts while taking the image" because the distortion is also a function of time.
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"(or other object I suppose)"
As I understand it the wobble mirror can use a reference star outside the field of view, it's not bound by the target. Theoretically you could use post-processing to build an image but the reason I like wobble mirrors is their engineering "elegance" makes all that complexity redundant.
Distortions (Score:1)
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No.
Well done! (Score:3, Interesting)
Keck held the "world's largest" title (among optical scopes) for the last 15 years; it'll be interesting to see whether anything steals the crown from the GTC in the near future.
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http://en.wikipedia.org/wiki/Giant_Magellan_Teles
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Bring on the (segmented) Thirty-Meter Telescope, I say.
During the daytime ... (Score:1, Funny)
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At last! (Score:2)
Fresh wallpapers for our desktops!
Seriously though, it's both incredibly funny and somewhat sad that that seems to be the Hubble's greatest legacy. Still, I'll happily drink to continued scientific progress funded by people's desire for cool pictures.
Grand Canary Telescope finds Big Bird (Score:2)
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To a science amateur or geek, sure, but not to an actual space scientist, thank god.
First shot! (Score:2, Funny)
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Satellite Image of the observatory (Score:3, Interesting)
Pretty cool, you can zoom right in. Guess we'll have to wait for Google to scan the Earth at night so we can see it exposed ;).
Why Earth telescopes? (Score:2)
So why are they building this one now and not e.g. helping fund the James Webb Telescope or perhaps some other upcoming plan?
Is there still much left to discover from the surface of Earth?
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Also, remember that the JWST is not serviceable. If its mirror doesn't unfold, well, that's it. The GTC has 6 spare segments so that a rolling re-aluminising can be done.
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(1) They are MUCH cheaper then space telescopes. Maybe 20X cheaper. There ground based scopes only cost as much as a few Hollywood blockbuster movies. We can't afford more then about one space telescope per decade so this means there is more demand for time then a space telescope can supply
(2) ground based scopes can be very much larger and collect more light
(3) Adaptive optics combined with the large size means the images are about as sharp from the ground as from spac
I work for an astronomy department... (Score:3, Interesting)
No, really! I work for the University of Floriday Astronomy department. The department has a 5% share of the GTC, and we're looking into another 5%. That may not seem like much, but if you consider one night of 10 meter time can be enough data for a graduate thesis, it's a massive amount of time.
The IR instrumentation group in my building is building a _giant_ instrument for the GTC. It's called FLAMINGOS-II. IR is where it's at in astronomy right now, so it's neat to be in an up-and-coming department.
If you guys have any questions about the telescope, I'll do my best to answer them or find out for you.
Largest? (Score:1)
why Gran Canaria over Tenerife? (Score:2)
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For an astronomer, there's nothing "benign" about hot air. It causes optical distortions.
Need to specify optical (Score:1)
hexagonal? (Score:2)
I was going to moderate as 'flamebait' but then figured I would ask.
Did you intentionally chnage the word hexagonal from the original article or was it a strange aouto-correct error?
If so, you need to ad the word hexagonal to your dictionary.
Otherwise, you have a very strange sense of humor.
Re:hexagonal? (Score:4, Funny)
Did you intentionally chnage the word hexagonal from the original article or was it a strange aouto-correct error?
I had a telescope with "12 homosexual segments of the primary mirror for testing and observations" once. Unfortunately, all it was good for is observing Uranus.
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They already found that, but it required that they use the Big Ear [wikipedia.org], and listen for the source of a faint but recognizable "Khaaaaan!" [khaaan.com] that's been reverberating about the galaxy for awhile now.