Mount Graham International Observatory is located in a very remote part of Arizona. The nearest town is Safford: small, tangibly insular, yet friendly.
I decided to try visiting the MGIO on the spur of the moment, after Kim left Tucson bound for Colorado and my trip to Flagstaff only two days away. I was not certain I would be able to visit the MGIO by just dropping in. Unlike Kitt Peak, the MGIO is a private institution, run by the Steward Observatory and was in the middle of a large-scale construction project, building one of the world’s most advanced and unique optical telescopes.
But I headed out that night, anyway, on long, dark Arizona roads, through deserts and hills, for hours, never knowing if I was lost or not, once I exited from the main highway. Safford is small, and in the middle of the night, I never knew if I’d quite arrived. But I did. And Safford was celebrating. Eating a peaceful dinner at a local Denny’s, the restaurant suddenly filled with uncomfortably dressed-up teenagers. I think it had something to do with High School football championships and homecomings. Coincidentally, my waitress was from Tacoma, Washington, which seemed impossible, since I was obviously in the Twilight Zone. Or perhaps that made it possible. Anyway, something about her husband and jobs, or no jobs, or family — and traps out in the open, in big spaces.
So, to the hill top: I thought it was nerve wracking reaching the mountain top of Kitt Peak, but Mount Graham was far more challenging. The last twenty minutes were skidding tires on the loose gravel of unpaved roads, and sheer drops to oblivion. The drive has a few unbelievable twists and turns, but the scenery is striking.
Traveling up the mountain you see several dramatic changes in scenery as the altitude increases. The base of the mountain is traditional Arizona desert. But there were times on the drive up I could swear I was back in the Pacific Northwest. Apparently fire is a big concern up here, having burned very close to the MGIO on occasion. There also seems to be a certain level of anxiety between people who like rare squirrels and the MGIO people.
By the way, they have armed guards and guard dogs on the top of Mount Graham.
I’ll start off with the least impressive things first. The Pope himself has his fingers twiddling in the pot up here. Even after the heresies of Galileo’s telescopic work, the Vatican has erected their own star gazing equipment here at a facility called The Vatican Advanced Technology Telescope. Actually, the Vatican has one of the oldest astronomical programs in the world, based out of the Pope’s summer home in Italy. The VATT telescope has a history of good science and continues to contribute. It’s one of the smaller installations I looked at, but size isn’t everything. They certainly have the most plush living quarters of any site I’ve visited to date.
The telescope of the VATT is actually called the Alice P. Lennon telescope in honor of the principal money contributor. Maybe she was trying to tell them something. Gosh, my irrational biases are showing through. But I do like hearing this: In 1992 here is what the Vatican had to say, officially, about their problems with Galileo:
“From the Galileo case we can draw a lesson which is applicable today in analogous cases which arise in our times and which may arise in the future. … It often happens that, beyond two partial points of view which are in contrast, there exists a wider view of things which embraces both and integrates them.”
(The addresses of the Pope and of Cardinal Poupard are published in L’OSSERVATORE ROMANO, 1 November 1992).
I like that. I wish they could come to the same conclusions with contraception and homosexuality. Maybe in a few hundred years. Their workshop is comfortably messy at the VATT, though, which is reassuring.
Now to some fun. The MGIO also hosts the Heinrich Herz Submillimeter Telescope which is actually a radio astronomy dish. But not just any radio dish. It’s incredibly accurate, with its dish surface unable to deviate more than 15 microns. Submillimeter astronomy is fairly new, and very difficult.
When we look at stars, we normally see visible light. But as we know, this is a very small portion of the electromagnetic spectrum. Radio telescopes deal with wavelengths that are longer. This gives radio telescopes the unique ability to “see through” obstacles in space, such as interstellar gas clouds. Radio telescopes can also see gas clouds that would normally be invisible to us, unless a star were nearby to light the cloud.
Submillimeter astronomy is very, very good at allowing us to determine the chemical composition of the greater portion of stuff out in space. This helps us to learn which elements are actually floating around and how they interact to form just about anything we experience.
Most radio astronomy is not terribly difficult. But in the submillimeter range we have an issue with our atmosphere. Interestingly, our atmosphere is very particular about what it filters out. If you go down lower than visible light, including the infrared, our atmosphere filters it, until we reach low enough to things like FM radio and short wave radios. If you go above visible light, our atmosphere just goes crazy filtering out the ultraviolet, x-ray and gamma-rays. Very convenient for us. But irritating for submillimeter astronomers.
So, like optical astronomers, submillimeter astronomers go up into the hills as far as they can to minimize the amount of atmosphere the radio wave must traverse to land upon their dishes. Normal radio astronomers have it easy. But at least submillimeter astronomers can ignore the daytime and the nighttime in the same way that radio astronomers do, unlike their optical counterparts. The sun is the ultimate in light pollution.
I think of the three observatories on Mount Graham I felt the most comfortable at the SMT. I admit, in large part it’s because of the barbecue and chairs sitting out front. But there’s something about radio astronomy that is just far more geeky to me than optical astronomy, and I suppose that’s comforting. We cannot see radio waves. Yet we can create images based upon radio waves, and these images represent far more of the universe than we would ever be able to see with just our eyes. It’s peering at the invisible. And as most of our universe, by far, is invisible… well, it’s a little titillating.
Unfortunately, the SMT was packed up and abandoned when I was visiting, so I didn’t get to see much action. But their website has some nice pictures. Like most of the observatories I visited, they use Linux. So much specialized equipment is used in astronomy that it seems the open nature of the computer operating system is perfect for allowing the most intimate and flexible interfaces. I’ll be doing a bit of a study on this soon, if I can get the time together.
But I do have to mention one more thing about the SMT. Biologists in particular might find it fascinating. For some reason, moths love the SMT building. No other building on the mountain had them, but the SMT was literally swarming with them, covering the walls, the ceilings, and even clumped on the floors in places. Apparently it’s a known issue. I found funny little printouts of moth species and diagrams posted on cork boards and several of those blue, shocking insect death devices were hanging about. Something there the moths find compelling. The SMT’s version of bats in the belfry, perhaps.
OK. To the big guns now: the monster truck dominator of optical astronomy, the One, the Original, the Large Binocular Telescope (LBT). This baby is huge. So huge I couldn’t get it all in one photograph. It’s glorious. It’s big and hard. And best of all, it’s bright red and chrome. Seriously. It’s bright red. And chrome. Any greasy-fingered muscle car mechanic would love this telescope.
I suppose that’s not the most important thing about it. But let me just say again, it looks really cool. Really cool.
Did I say it was big? As I approached the building the LBT is housed within, it reminded me of the huge airplane hangers at Boeing, just raised up in the air a little higher, and not quite so long. And the whole top of the building spins around in circles to point in any direction. This makes for some interesting hallways inside the building, by the way.
Again, that’s not very important. But the control room is very nice, too, and they use nearly all Linux machines. Big living quarters, too, modern, clean, institutional, yet comfortable. Four or five big refrigerators in the kitchen…
OK. Sorry. Yes, BIG. The LBT which will be fully operational within just a few weeks is going to be one of the most advanced telescopes we’ve made. It’s very strange using two mirrors to gather light. You might wonder, why would you want to use two, when you can make one great big one? Well, because this is cool. And ok, yes, it’s cheaper. But more efficient, too.
The LBT was built through a cooperation between several organizations in Italy, Germany and the US. The Italians made the race car chrome. The US made the mirrors. I’m not sure what the Germans did — maybe they just threw money, or did the engineering. But whomever did what, it was done for a very good price, considering the imaging you get. And the whole schmeer is creative as all hell. That’s not just a saying — it was hell coming up with what they needed. But they did it.
Each of the mirrors that gather light have 8.4 meter apertures. That’s nearly 28 feet. That’s pretty big for a mirror, but not quite the largest. For example, the Keck Observatory has a 10.0 meter mirror. But when we combine these two 8.4m mirrors in the LBT through a process of interferometric imaging (a kind of overlaying to amplify or cancel light waves based upon phase differences), we end up with the light gathering capacity of an 11.8m mirror, and the resolution of a 22.8m telescope. Besides, Keck cheated. Their big mirror is really 36 little mirrors all bunched up together.
Making an 8.4m mirror was really quite a big deal. Normally mirrors are made by taking a giant slab of glass, then grinding it down to shape and polishing it. The problem is, when you get to 8.4m sizes, the sheer weight of the glass chunk you would need is far too great. You end up with a very unstable mirror, if you manage to get one at all. Happily, the Mirror Lab at the University of Arizona has developed a novel approach to creating mirrors. They take glass, melt it down, then put it into a mold where it is slowly turned for a very long time, spreading out into its parabolic shape, then slowly cooled and polished. The interior of these mirrors is a honeycomb, so they are very light and very strong. It’s a truly revolutionary process that the Mirror Lab is just starting to prove in the astronomy world. As an added bonus, it’s far cheaper than the traditional glass grinding process. Ironically, all this arcane work goes on unsuspectingly below the University of Arizona football stadium.
University of Arizona/Steward Observatory/MGIO/LBT
So what does this mean for astronomy at the LBT? Since the proof is in the pudding, and the pudding is not finished baking, we can’t say for certain. We’ve all seen Hubble images, though. The LBT should be able to see much further, and image objects with over 10 times the clarity. What about the atmosphere though? Doesn’t it make everything all wavy and blurry? Why yes, it does.
We won’t let that bother us any more, though. The LBT uses secondary mirrors for each of the 8.4m mirrors. These secondary mirrors are very thin – only about 2 millimeters. So thin they’re bendy. They also float it in an electromagnetic field. And that electromagnetic field has around 670 “actuators” that are each controlled by a computer that bends this little mirror by nanometers very, very quickly in real time, based upon a reference star the computer watches up through the atmosphere. No more atmospheric distortion…
When I was there, only one of the mirrors was installed. The other was recently brought up the mountain after a long convoy ride on cleared and blocked-off interstate highways, from the University of Arizona Mirror Lab. It was in storage, waiting to be installed. But there were a couple very nice operators who were kind enough to show me a lot of the software developed to control the scopes, as well as moving that giant beast around so I could get a good look at the mirror surface that was installed.
The software is all home-brewed, Linux-based and very simple to use. I’ll be documenting all the software used at these various places soon, but I probably won’t be posting it here. The LBT is an engineering wonder, just bursting with creativity from many disciplines. They even developed a new method to re-silver the mirrors while they are left in place on the telescope — a process that used to be a major undertaking for an observatory.
This Fall we should be seeing what this hot rod can do, with those Italians, Germans and desert people tearing into the cosmos. Optical astronomy will most certainly take a big leap forward. Possibly not as quickly as it might, unfortunately. One of the drawbacks of private facilities like the MGIO is that only the people involved will ever get to use it, unless deals are struck or new alliances forged. C’est la vie.