Kitt Peak, Up and Down

Mayall 4-m TelescopeIt’s been some time since I last wrote anything about my travels to observatories in Arizona and New Mexico last year. In just a few months I’m heading back, so it seems like a good idea to finish up last year’s stories first. But they’ll likely be far more abbreviated than I intended.

My last post on the observatory tour mostly concerned some history surrounding Kitt Peak. Now to the more nitty-gritty.

One of the most striking things to me about Kitt Peak, other than the nerve-wracking drive up, is the sheer number of observatories on the peak. From nearly anywhere you stand, you will see several astronomical structures in any direction, of varying heights, on varying hill prominences, all together making what feels like a cozy little village of high-tech instruments contained in domes.

Kitt Peak is a national observatory. This means that it is funded mostly through the US government, namely the National Science Foundation. This was actually slightly revolutionary. Historically, the tools used to study Astronomy were constructed solely from private resources, whether individuals, foundations, or universities. The people who built the observatories were the only people who used the observatories.

Kitt Peak represented a fundamental shift within the science of Astronomy by allowing any individual, group or entity to apply for time at Kitt Peak for little or no money. This gave the academic word a huge boost since scholars could now have access to very good astronomical tools regardless of their institution’s ability to pay the massive observatory project costs on their own.

Since astronomers could use all the equipment at Kitt Peak for free, the data they gathered would become public knowledge. At the conclusion of their observations, a “proprietary period” began, lasting nearly two years, where their data would be wholly their own to work with. After this period, the data becomes available to everyone.

Vera Rubin
Vera Rubin at DTM image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970.

Kitt Peak has done a lot to advance our understanding. One of my favourite things is Vera Rubin studying the rotation of galaxies. Back in 1970 she published a paper which still proves to be one of the strongest arguments supporting the existence of Dark Matter in the universe. She used the 84-inch Kitt Peak mirror to determine that galaxies rotated far more quickly on their periphery than they should. This means it is very likely a significant amount of mass exists in galaxies that we simply cannot see.

Interestingly, when Vera was being interviewed for admissions to science at Swarthmore, one of the things she told the interviewer offhand was that she liked to paint. The interviewer asked if she’d ever considered painting astronomical objects. Good thing she didn’t choose that. Now, her discoveries feed into one of the modern “holy grail” mysteries of astronomical and cosmological science — not to mention various physics.

But lots of excellent science goes on at Kitt Peak, even some directly practicable work. The Near Earth Objects (NEO) program coordinated by NASA and with a heavy interest and investment by the United States Air Force, works to discover objects hurling about our solar system that might one day impact Earth unleashing devastation. One of the programs that comprise the NEO program is the Spacewatch program which operates two telescopes on Kitt Peak. They are indeed pioneers in the field and contribute much to the project, particularly in identifying smaller or less luminous NEOs.

McMath-Pierce Solar ObservatoryProbably the most distinguishing feature of Kitt Peak, besides the titanic, panoramic view of Arizona’s landscape far into the horizons, is the McMath-Pierce Solar Telescope. Another remnant of the Kennedy Era, this National Solar Observatory telescope remains the largest in the world, particularly capable at exploring the infrared spectrum beyond 2.5 microns. Unfortunately it was closed for a construction project while I was there so my lovely retired physics professor friend couldn’t take me in. However, he did suggest that someone might easily sneak in. He was right.

The solar observatory starts approximately 100 feet in the air, travels down diagonally around 200 feet, then bores down into the mountain another 300 feet. So, the largest portion of the observatory is actually underground, as is the instrumentation. The heliostat optics which sit at the top of the 100-foot column weighs in at 27 tons and is mounted on a track that extends down toward the primary mirror. It can crawl along this track at 4 feet per minute. The first mirrors used in the observatory were freely given to Dr. McMath by General Electric. These quartz mirrors were just sitting around in the yard at General Electric, unused, having been created twenty years prior for the Mount Palomar Observatory. It was either give them to Dr. McMath, or throw them away. So Dr. McMath just paid the cost of transporting them from General Electric to Kitt Peak. Well, after getting them ground and processed into the exacting specification first, including coatings of molten quartz, and an accidental cracking of one… and, well, subsequent welding together for a quick patch-up. In 1966 the welded mirror was replaced after the slight warping became too much to bear.

Heliostat on the McMath-Pierce Solar ObservatorySadly, Dr. McMath died the month before the observatory was to be dedicated. And to think he left his Detroit family’s bridge construction business after a bridge he was working on collapsed with him on it.

The solar observatory circulates over 16,000 gallons of water and anti-freeze. The tower is cooled during the summer by circulating the liquid around the copper infrastructure. However, the larger portion below ground is not cooled, since the temperature is fairly constant and cool from the earth itself. Interestingly, the portion below ground is cooled in the winter to help equalize the temperature with the winter air above ground.

One of the things I heard often in my travelings around observatories is that astronomy is a cold business. Optical astronomy is for the night, usually as high up into the atmosphere as you can get. The tragic part is that the mirrors pointing toward the sky and the mirrors inside, down where you are, must be the same temperature. I’m sure astronomers are happy with modern innovations in automation that allow most astronomy to now be performed remotely.

Returning to Kitt Peak specifically, it is a publicly-funded institution. Scientists who apply for telescope time and are accepted usually come to Kitt Peak to live in the dormitories during their study. It’s simply too difficult a commute to make every day, particularly in the black of night, where you cannot even use your car lights.

Also, adhering to its status as a public institution, Kitt Peak offers guided tours during the day. They also have an excellent nighttime observation program (NOP) available to the public. I attended this and was very happy. About 25 people showed up that night, just before dusk. We were given a brief tour of the grounds while light remained, then attended a lecture on astronomy and observational techniques. We were even trained on using a planisphere, which lets you easily find the locations of stars and constellations. They even fed us.

After we were sufficiently trained, we moved outside. The blackness of night is difficult to describe. The closest city is Tucson which has strict lighting ordinances designed to minimize light pollution. City light are dim, outside house lights must be covered, pointing down only, and street lights must be made of a specific chemical that is not only dim, but can be easily filtered out of optical observations made at Kitt Peak. The effect in Tucson is actually rather beautiful.

But the effect at Kitt Peak is stunning — there is practically no effect. The lights of Phoenix which are considerably further away cause more light pollution than Tucson. Blackness. And no lights allowed on Kitt Peak. It’s easy to run into someone accidentally who is standing right next to you. But up above, the view of the stars splashed impossibly numbered across the sky is staggering. You only truly begin to realize you’re on a planet within a vast sea of emptiness and space when you see a sight like this.

In the meantime, you know that in the many observatories around you people are busily working away on their sciences, moving in shadows through the cold night landscape only when necessary. There exists a feeling of quiet purpose and profoundness that we in the lit, busy streets forget is always there above our heads, in its overwhelming hugeness.

After examining the night sky for a while, being told histories, locations, discoveries, and strange truths, we split the group in two, heading to look at these skies through telescope of our own. It is here that you realize the difference in traditional observation and the technical advances we’ve made.

Mainly, all objects in the sky are very far away. When we look at them, even through a telescope, we see only the very brightest that the object has to offer. Seeing another galaxy, a collection of billions of stars, so far away. An exploded cloud of gases. So tiny from here, so dim — yet truly enormous. The trick to seeing them more vividly is how long you expose its image, whether on photographic material, or electronic CCD’s. When you look through a telescope, as I said, you can only see the brightest. But leave that brightness, and the hidden dimness exposed long enough, and the glorious details emerge.

During my nighttime visit I was lucky enough to meet a wonderful guy name Michael who was similarly very interested in astronomy but had chosen a different path. Kitt Peak also offers an advanced observation program where you spend a whole evening with a telescope, imaging equipment and even a technician, and a place to sleep. It costs around $450/night, but two people can participate at once. Michael and I discussed the possibility of participating in this amazing little program — I sincerely hope that one day soon we will actually get around to doing it.

In the meantime, the drive home from the nighttime observation program can be a little terrifying. Remember the horrific drive up the mountain I described? That was during bright daylight. To leave the mountain, you must drive down those same perilous roads, but using no headlights. I’m just happy I was a few cars down in the train leaving so I could follow the parking lights of the car in front of me. Of course, had they gone off the cliffs, I would have soon followed.

Kitt Peak was my first stop on the observatory tour. It was transforming. And I promise, for anyone, it would be most inspirational.

NGC 4038

By the way, this image was taken by Bob and Bill Twardy/Adam Block/NOAO/AURA/NSF from Kitt Peak’s Advanced Observation Program. It’s galaxy NGC 4038. It used to be two galaxies, but they have collided, much like our Milky Way galaxy will soon collide into our neighboring Andromeda galaxy. The wispy, curled lines off to either side are stars from each galaxy that have been thrown off into intergalactic space from the gravitational forces of the collision.

Next comes Mount Graham Observatory.

Oh, did I mention that Kitt Peak also houses one of the radio telescopes that comprise the Very Long Baseline Array? It’s an array of radio telescopes that span over 5,000 miles, all combined into one. It is the sharpest, most far-seeing thing we have. As a cute analogy, consider reading a newspaper in Los Angeles from the top of the Empire State Building in New York.

Oh yes, and a rich business man turned astrophysicist (Edgar Smith) rents out a space at Kitt Peak and built his own high resolution observatory. It’s the only private telescope there. I think the last man to put his own money into Astronomy was Purcival Lowell. And Lowell Observatory will be coming up in a short while, too.