The Cosmic Mystery: A siren song of curiosity and discovery

Notes on Stargazing

Last month, Peter Breslow traveled to Tuscon, Arizona in search of stargazers for NPR's Weekend Edition.

And he met plenty who gathered for the historic transit of Venus. Amid the folks gathered in the ludicrous Arizona heat, Breslow encountereed one Dean Ketelson, "An astronomy cheerleader if there ever was one". Ketelson enjoyed a career at the University of Arizona, but settled in after retirement to work at Kitt Peak, leading stargazers to the Grand Canyon, and lending his efforts to the Giant Magellan Telescope.

Here's where the story gets crazy:

BRESLOW: We are under the towering east stands of the football stadium where the University of Arizona Wildcats play. This cavernous space was the best spot to house the Steward Observatory Mirror Lab. Here giant telescope mirrors, three feet thick and almost 28 feet in diameter, are being cut to perfection by a mechanical polisher that works around the clock across the face of the glass like an automated Zamboni. The process, honing to within a millionth of a millimeter, takes forever.

How do you know when you're done?

KETELSEN: This one we just started polishing so we're still almost - we're supposed to finish it this year. But I think end of the year, first part of next.

BRESLOW: And the other one?

KETELSEN: The other one might be finished.

BRESLOW: But making that call isn't easy says polishing technician Tabor Tollefson.

TABOR TOLLEFSON: We know that if we do everything right we can improve that mirror. I mean, it's darn near perfect, but we can make it better. But one miscalculation, one little error, and you know the closer you get to perfect the easier it is to screw it up.

BRESLOW: Two years ago, they went just past perfect, poked a hole in the glass and lost six months fixing it. In eight years, when this batch of mirrors is complete, it'll be shipped to the northern Chile where the Giant Magellan Telescope will reside 8,500 feet up in the Atacama Desert.​

The idea of polishing a mirror twenty-eight feet across with a tolerance of less than one nanometer?

Then again, the GMT will be the ultimate earthbound stargazer:

It is a segmented mirror telescope that employs seven of today's largest stiff monolith mirrors as segments. Six off-axis 8.4 meter or 27-foot segments surround a central on-axis segment, forming a single optical surface with a collecting area of 24.5 meters, or 80 feet in diameter. The GMT will have a resolving power 10 times greater than the Hubble Space Telescope.​

It is, by any measure, a tall challenge. And an expensive one. The estimated $300 million cost for construction and implementation is being underwritten primarily by philanthropic foundations. In April, the GMT project, recognizing that certain public funds could be better applied elsewhere in the scientific community, passed on a five-year, $1.25 million funding opportunity through the National Science Foundation, though the $250,000 a year still turns up in their appeals for support. The GMT has already received $10 million from the NSF through the Association of Universities for Research in Astronomy [AURA].

Meanwhile, as astronomers look forward to the planned 2020 opening of the Giant Magellan Telescope in Chile, Breslow, back in Tuscon, finds the stargazers enjoying a commercial venture that might well not exist but for the city's regulation of light pollution:

BRESLOW: The solar powered Sky Bar in downtown Tucson is featuring fire dancers tonight. Performers flip flaming batons while in a nearby parking lot patrons sipping beer take a glimpse of the stars through the bar's 14-inch telescope. Pointing people in the right direction is Sky Bar's resident pro Rob Tackett.

ROB TACKETT: I take care and run the telescopes here at Sky Bar. And I run a small observatory outside of town at a bed and breakfast and I do parties. I bring telescopes to parties.

BRESLOW: I didn't know you could have a job doing that.

TACKETT: Yeah, neither did I until a couple of years ago.

BRESLOW: Tackett's job is made easier by Tucson's stringent light pollution laws, limiting bright billboards and beacons that shine upwards.

WENDY CRAFT: My favorite star binary star is Albireo, and it's really awesome. And then you can also see the globular clusters really clearly as the night progresses, because as they get higher up in the sky there's less atmosphere to get in the way of things. So you can see them really clearly. So, you stick around.

BRESLOW: That's self-described telescope girl Wendy Craft, a pixie-sized blonde who flutters like Tinker Bell around Sky Bar's scopes. Tonight, she's helping viewers zero in on Saturn and its rings, which appear so huge and perfect they seem like a prop left over from a 1950's sci-fi film.

CRAFT: Saturn, we're on Saturn right now.

KEIRAN BROOMICUM: Can I have a look?

CRAFT: Of course.

BRESLOW: Keiran Broomicum is visiting from Exeter, England. He says he's come to the desert southwest for the nighttime sky.

BROOMICUM: So that's kind of cool.

CRAFT: Yeah. Kind of?

BROOMICUM: I like that.

CRAFT: Yeah.

BROOMICUM: That looks so good it almost looks fake.​

And you have to admit, there is something cool about going to a bar to discuss your favorite binary star system.

And, well, a 24.5 meter telescope situated at what is perhaps the best observation point on the planet?

What we find in Breslow's report is a mix of elements describing the human attraction to the cosmos. To the one, scientists are reaching to understand fundamental questions of the Universe, and there are certainly those who see no value in this. But, to the other, stargazers will cross oceans and continents alike for a better glimpse into the cosmos. The passion of each suggests something about the nature of human curiosity, which cannot, it seems, be quelled by any one discovery or accomplishment. Understanding how our human endeavor fits into the larger universal scheme has been a quest for our species since before we invented gods to explain the mysterium of nature. And throughout the generations, the search for answers has brought a net profit to the human endeavor; we are still here, still growing, still learning, and still searching.
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Notes:

Breslow, Peter. "Starry-Eyed In Arizona Observe The Heavens". Weekend Edition. July 14, 2012. NPR.org. July 24, 2012. http://www.npr.org/2012/07/14/156772238/starry-eyed-in-arizona-observe-the-heavens

Giant Magellan Telescope Organization. "The GMT and the NSF Funding Opportunity: An Explanation for our Astronomical Colleagues". Press Release. April 2, 2012. GTM

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rg. July 24, 2012. http://www.gmto.org/pressrelease07a.html

See Also:

Giant Magellan Telescope Organization. http://www.gmto.org/index.html

 

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Interesting post Tiassa. The desert plateau's of Arizona and New Mexico are very good locations in the continental United States for astronomical telescopes. Minimal humidity/cloud cover/light pollution. Chile is better yet and hosts approximately 45% of the worlds astronomical infrastructure.

 

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Brief comment. Although the mirrors are indeed critical, the complexity of a modern astronomical telescope goes far beyond that. Super-cooled dewars containing extremely sophisticated CCD detectors are required to capitalize on increased resolution. This in turn requires a concomitant sophistication in photometrics. A sophisticated operational infrastructure (mechanical/digital) with highly-trained technicians is another requisite. In totality, such astronomical endeavors are extremely complex.

 

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