Slashdot Mirror
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.
I certainly see a lot of GMTO articles around the 'net, as opposed to the other two projects. Interesting, that.
You're another asswipe who doesn't know a Magellan from a TMT. Hawaiians have a word for people like you: Haole. Just saying. Must suck to be you.
-- "I'm not in a hurry; I'm in Hawaii." The Homeless Guy
It seems like the Moon's surface could be a fantastic place for an absurdly large optical telescope. No significant atmosphere, little or no vibration, low gravity (making for less distortion of the optics), and plentiful raw materials for making fused silica and aluminum surfaces.
Obvious drawbacks: not a good place for humans, a two-week period of daylight (not necessarily a deal-breaker without an atmosphere, but a source of thermal stress), and a REALLY BIG dust problem.
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.
The editors of Slashdot should not allow self-promotion. StartsWithABang is Ethan Siegel and we had several of these astronomy and science stories submitted by him that link to his own Forbes articles!
Well given that Forbes doesn't like my ad blocker (and quite a few people on /. run ad blockers for very good reasons) I'd say he's shooting himself in the foot by linking to his own articles on Forbes. He'll never get page views from all of us ad blockers, and eventually someone will post a link to a similar story on an ad blocker friendly site and their page view stats will go up.
But yeah. Shills still exist on /. no matter what whipslash* has said about cleaning them out, and stories like this always seem to bypass the firehouse.
*We loved you Whipslash when you spoke about cleaning up /. but when need to see you follow through on this or we will turn on you and opine about "Meet the new boss, same as the old boss".
I am Slashdot. Are you Slashdot as well?
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.
I was incredibly fortunate to be invited to the official groundbreaking event for the GMT last November, which concluded with one of the most memorable experiences of my life.
Just a couple of kilometers away from the GMT site are the twin Magellan telescopes. These telescopes are both 6.5 meter aperture and have a large number of instruments that astronomers can use, with fairly easy switching between instruments. That night the telescope staff did something extremely rare. They fitted the Clay telescope with an actual eyepiece and all 190 guests were allowed to look through this 6.5 meter telescope! (The president of Chile got to go first, of course.) For this event, the telescope was trained on the saturn nebula and with this much aperture the colors were quite striking even to human eyes.
One of the astronomers told me that the number of people who have actually looked through such a telescope doubled that night.
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.
and a REALLY BIG dust problem.
Is that much of a problem? Doesn't it just stay on the ground?
No, it doesn't..
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Don't forget the bane of all new telescopes - it will definitely be cloudy the first time you try to use it. Heck, even buying a new eyepiece can clause clouds in my neighborhood!
Yep. My astro club calls it the "new equipment curse" and if a star party clouds out, they look for the culprit (in good fun of course).
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Followed by the BFT (Big... you get the idea)
There is no suggestion or prospect of doing long baseline optical interferometry with any of these telescopes, mainly because no one knows how to do it. Optical interferomteres cover at most 100m or so.
The reason for wanting one of these telescopes in the Northern hemisphere is simply so it can see the Northern sky.