Magellan Telescope First Mega-Mirror Polished and Ready

coondoggie writes "One of the six giant — 27 feet across, 20 ton — circular mirrors that will be part of the 4,000 sq. ft., Giant Magellan Telescope that ultimately look for stars, galaxies and black holes has been polished and completed — now for the other five. The mirrors will form the heart of the 25-meter Giant Magellan Telescope, and when complete will provide more than 380 square meters, or 4,000 square feet, of light-collecting area." This is a big project, not just a big mirror. From the article: "At the Carnegie Institution for Science's Las Campanas Observatory in northern Chile, earthmovers are completing the removal of 4 million cubic feet of rock to produce a flat platform for the telescope and its supporting buildings. The telescope is scheduled to come online in about 10 years.

smudgy fingers

[Anonymous Coward]

No way they keep that thing clean and polished for 10 years... some jerk is gonna walk over there and wipe his finger on it. guaranteed

Re:

[k28]

I'm sure one of the first things that you think of when using big pieces of glass is the fact that they'll get dirty. A little bit of googling tells us that the mirrors will be regularly CO2 -cleaned, (basically blasting all dirt off the surface of the mirror) - see section 10.11: http://www.gmto.org/science-conceptu.html [gmto.org] . Each mirror will also get recoated every 2 years, to prevent scratches and blemishes.

Re:smudgy fingers

[ackthpt]

No way they keep that thing clean and polished for 10 years... some jerk is gonna walk over there and wipe his finger on it. guaranteed

No problem if a jerk does, there's an easy way to clean it - First Contact [photoniccleaning.com]

Spray on, dry, peel off.

Used by NASA and JPL.

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[NixieBunny]

The photo that the mirror lab emailed to me with this announcement showed them applying a blue sticky protective coating to the mirror. So don't worry; it's well protected. Furthermore, they don't even put the aluminum on it until it's at the telescope.

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[smi.james.th]

Big telescopes like this are usually kept away from where people an get to, I've seen a few large optical telescopes. This sounds bigger than any of them though.

10 years!?!

[who_stole_my_kidneys]

in 5 years it will be obsolete, there will be yet another telescope launched into space that can see far greater distances before this is even built.

I'm wonder why anyone would even bother putting a telescope on the planet at this point, put it on the moon , no atmosphere to obstruct your view.

Re:10 years!?!

[Joce640k]

I'm wonder why anyone would even bother putting a telescope on the planet at this point

It's cheaper.

Re:10 years!?!

[afidel]

Yeah, no kidding. The GMT has a total budget of $700M, JWST's annual budget is almost that much.

Re:10 years!?!

[ackthpt]

I'm wonder why anyone would even bother putting a telescope on the planet at this point

It's cheaper.

Further, with corrective optics they get amazing results. I'm a member of the Santa Cruz Astronomy Club and we have been lucky enough to have some great speakers come in from US Santa Cruz (who manage some large earthbound telescopes, including Keck on Mauna Kea, Hawaii) Directing a laser into the atmosphere allows them to correct a high percentage of anomalies, obtaining some much improved results over non-adaptive optics. This technology has given new life to old optical scopes, further cost far less than adding yet another spaceborne scope, which may lauch correctly, may deploy correctly and may work for a sufficient amount of time to justify the costs of everything, including the team using it. UCSC also does some amazing work with mirrors, polishing to molecular uniformity and applying coatings a molecule in thickness. Amazing stuff.

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[Anonymous Coward]

It won't really be obsolete if it doesn't have any competition... This thing's gonna be MASSIVE.
ure, the James Webb telescope may be running by then (far from certain, though) but that will only observe in the infrared. And besides, do you know how much competition there will be for the exposure time? It's hard enough to get time on a good telescope as it is.

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[theJML]

Might have a little competition from this: http://en.wikipedia.org/wiki/Thirty_Meter_Telescope [wikipedia.org]

25m is a bit less than 30m. Just saying.

So its redundant

[Anonymous Coward]

Yes, because there is so much telescope time available, and so few astronomers to use it.

Oh, wait...

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[k28]

The GMT has 7 mirrors, each 8m wide. The 30m Telescope has one 30m mirror, plus a 3m secondary mirror. I'm not sure which would be optically better, but I'd guess that the GMT will have more uptime as you can remove a mirror for cleaning without taking down the entire telescope.

Re:10 years!?!

[PerMolestiasEruditio]

in 5 years it will be obsolete, there will be yet another telescope launched into space that can see far greater distances before this is even built.

I'm wonder why anyone would even bother putting a telescope on the planet at this point, put it on the moon , no atmosphere to obstruct your view.

4 times higher resolution than James Webb, 12 times the light collecting area, 10% of the cost.

Space telescopes are only sensible for the sections of the spectrum the earth-bound just can't do.

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[14erCleaner]

I'm wonder why anyone would even bother putting a telescope on the planet at this point

This scope will cost about $700 million to build; the Hubble Space Telescope cost $2.5 billion initially, and about $10 billion over its lifetime. Much better bang-for-your-buck to build telescopes on the ground, even if the space telescopes can do more. Sometimes quantity is better than quality.

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[afidel]

First the James Webb Space Telescope is on the edge of being chopped from the budget, second even if it's not chopped it looks like it will be 2020+ before it launches, and third it's only better in certain parts of the spectrum. Not only that but the JWST can only observe so much of the universe at a time, having multiple mirrors collecting data means we're more likely to pick up interesting data. As to the moon idea, sure once we have a heavy launch vehicle with a non-trivial lunar orbit injection capabil

Re:

[Anonymous Coward]

And what if someone builds another, better telescope at some point? Astronomers use a lot more than just the single best telescope out there. If a better telescope is made, older ones don't become instantly useless. It would only be useless when the operating costs become too much for what it can be used for. That would take quite a few better scopes being built and technological improvements being made before access time on better scopes is easy enough to get that no one would want to use this one. Wh

Re:

[Anonymous Coward]

How does that compare to the Ludicrously Large Telescope?

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[Bengie]

I would love to see someone put a 120ton telescope into space. The clarity of a telescope is mostly a function of the amount of light it can collect, so one would still need a very large space based telescope to compete with the ground based one.

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[sexconker]

(4.32 x 10^-6) / (525600 * 60)

Time isn't metric, but all you need to know is 60 seconds per minute and that song from Rent.

See that

[sunking2]

The UA football team is funding science by letting them set up a lab in the musty cellar of their stadium!

Re:

[NixieBunny]

Both football and telescopes are multi-million dollar enterprises at the University.

The mirror lab is built under the nosebleed section of the stadium, so it's not a cellar at all. It's a five story building built on a former parking lot.

27 what?

[Kickasso]

How much is this in bushels per acre?

Re:

[K. S. Kyosuke]

27 feet. That's obviously a pretty large bed, 13 healthy people and one Afghanistan amputee fit in it. It's just that we have no idea how many sleeping space a person has in it, so exact dimensions are subject to speculation.

Maybe the scope...

[wbr1]

.. can settle the dispute between these two guys: http://www.youtube.com/watch?v=zn7-fVtT16k [youtube.com]