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Giant Magellan Telescope Set To Revolutionize Ground-Based Astronomy
StartsWithABang writes: If you want to see farther, deeper and at higher resolution than ever before into the Universe, you need four things: the largest aperture possible, the best-quality optical systems and cameras/CCDs, the least interference from the atmosphere, and the analytical techniques and power to make the most of every photon. While the last three have improved tremendously over the past 25 years, telescope size hasn't increased at all. That's all about to change over the next decade, as three telescopes — the Giant Magellan Telescope, the Thirty Meter Telescope and the European Extremely Large Telescope — are set to take us from 8-10 meter class astronomy to 25-40 meter class. While the latter two are fighting over funding, construction rights and other political concerns, the Giant Magellan Telescope is already under construction, and is poised to be the first in line to begin the future of ground-based astronomy.
That's why I skip the articles and just look for the information I'm interested in. Like, hmm, how will this ground-based atmosphere-ridden telescope compare to the Hubble Space Telescope?
From the FAQ on http://www.gmto.org/ ... which is linked,
The GMT will leverage cutting-edge optics technology to combine seven giant mirrors to achieve 10 times the angular resolution of the Hubble Space Telescope in the infrared region of the spectrum.
When coupled with the GMT adaptive optics (AO) system they will produce images sharper than those from the Hubble or Webb Space Telescopes.
And it goes on to explain that the atmospheric turbulence 200 meters up can be measured with lasers, and the one of the mirrors is physically deformed to compensate for the measured distortions. Pretty neat.
It's a cool idea, no doubt. But no matter how good your telescope is, I doubt it can easily surpass observing systems in space like the Hubble. At its altitude, roughly 25% of the atmosphere is beneath it, which reduces the problem of scintillation. Furthermore, the position in the Atacama Desert means it's a dry place, so there isn't a big problem with moisture causing differences in air density, leading to scintillation or even just refraction by the atmosphere. That said, why in Chile? Why not in Tibet, where it could be positioned at an even higher altitude but with many of the same favorable characteristics of being dry and away from light and air pollution? I recognize that it just isn't possible to build an observatory at the summit of one of the higher Andean peaks, but Tibet is probably a better place. That said, why don't we have plans (that I know of) for a replacement for the aging Hubble?
This is a raft of AC questions. In order the answers are:
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
For those who don't want to visit Forbes, a site with a history of malware in their ads but insists that visitors disable ad blockers (and script blockers like Noscript)...
Here are a few links with more information than you'll get from Ethan's article, plus they don't require disabling ad blockers:
http://www.space.com/31079-giant-magellan-telescope-groundbreaking-travelogue.html
http://gizmodo.com/the-giant-magellan-telescopes-fourth-mirror-melting-is-1736954773
http://www.gmto.org/resources/
The technology is pretty damn cool, especially the adaptive optics to deal with atmospheric turbulence. It's worth a read, especially when you don't have to try to visit Forbes.
I really wish the Slashdot editors would stop letting this crap through. But because they do, it's a good service to everyone if users can provide alternate links that are better. In this case, there's a hell of a lot of good information on the actual GMTO site.
I hate all anonymous shitbags. Log in, you filthy bastards.
1) Google adaptive optics and be amazed.
2) Apparently the topography to windward (west) is important. Chile and Hawaii are favoured locations for telescopes because they have ocean to the west, and ocean is very flat (relative to land). That means the air blowing over your telescope is experiencing pretty laminar flow most of the time. Places like Tibet with lots of mountainous land to the west get more turbulent flow.
No. No, they won't.
Think about the distance to an airplane in flight. Next, think about the area of the sphere with that radius, and how little of that area even a giant telescope's mirror will intercept. You're not going to be blinded. You might be surprised, and you might lose your dark adaptation, but you're not going to be blinded.
Now, think about the area subtended by the telescope's field of view -- in the example above, a circle perhaps one minute of arc in diameter. What are the odds that a bright meteor will pass through that area during an observing session, slowly enough to linger long enough to cause damage? Pretty darn tiny. (Your odds may actually be worse if you aren't using the telescope, because then you're more vulnerable to a really bright meteor crossing your wide native field of view.)
The "real reason" eyepieces are rarely fitted to huge telescopes is because it's wasteful. The human eye is much less sensitive than the instruments normally fitted to such a telescope, and it doesn't record its perceptions for later analysis. Demand for real scientific observations from a large telescope always exceeds available time, so nobody wants to waste the machine's capability for some momentary sensual gratification.
As for safety, until planes are outfitted with multi-watt lasers specifically targeting telescope facilities, or until we're ambushed by a dense swarm of very bright meteors again targeting telescopes (so their apparent motion is slow enough to make them linger in a tiny field of view), our visual observers are pretty darn safe.
Besides, you only look through the eyepiece with one eye at a time, so you'll have a spare...