Holy molé. I'd forgotten what the southwest is like. I can almost hear the Sun. I'm glad the bus is air conditioned.

Kitt Peak National Observatory is an astronomical observatory located about 50 miles southwest of Tucson, Arizona. The observatory is situated on Kitt Peak, part of the Quinlan Mountains known by the Tohono O'odham as Ioligam. The observatory was founded in 1958, after a 3-year search by several universities. They sought an ideal site within the continental United States from which to conduct optical astronomy, and they found it on Kitt Peak. It remains the premier observatory of the southwest, and one of the best in the Northern Hemisphere.

The site is controlled by the National Optical Astronomy Observatory or NOAO, the United States' national organization which organizes optical astronomy in the United States. The Observatory has 24 telescopes, though more than half are controlled by independent groups or universities. The two most prominent ones are the 4-meter Mayall telescope, and the oddly-shaped McMath-Pierce 2-meter solar telescope. Though the site is controlled by NOAO, radio astronomy is also done onsite as well; NRAO's 12-meter is here, as well as a VLBA 25-meter antenna.

There's a whole lotta nothing out here, isn't there? Or mostly nothing. The desert is alive, even a little green in its season. It's amazing that people could live out here before the age of technology. They'll probably be living here after, too.

I can't believe they're trying to get a touring bus up this road. It's what, about 500 feet down over that ledge? I sure hope no antelope decide to hop in front of the bus. "Bus crash sets back amateur astronomy 25 years -- details at eleven."

Sure is a pretty view, though.

Kitt Peak is an ideal place for astronomy. The weather is clear and dry for a large fraction of the year. The seeing is very good, with sub-arcsecond possible at times. And it's very far from most sources of urban light and air pollution. In the early 1950's there was a lot of talk about how and where to best do accurate photometry of stars and other celestial objects. In 1952, astronomer John Irwin of Indiana University penned an article in Science magazine that suggested the southwestern United States would be a good location for a permanent, national observatory for performing optical astronomy.

It was a timely suggestion, given that the government was already predisposed toward funding space science (or, more generally, anything of a scientific nature with the potential to show up the Soviets). There was a push to do this on a national level, since many of the nation's top observatories (Palomar, Yerkes, et cetera) were in the hands of individual universities. Unless you were an astronomer at one of the more well-endowed colleges, you weren't likely to have access to large telescopes with which to do ground-breaking astronomy. The lack of a national facility was hamstringing astronomical research in the United States.

In the mid-1950's, several universities and prominent scientists approached the National Science Foundation about seeking government assistance in developing such a facility. In 1957, Associated Universities for Research in Astronomy (AURA) was founded by seven Universities with the purpose of developing and controlling an observatory. But rather than being used by only those seven universities, the National Observatory would be available to all astronomers at United States institutions on a competitive basis. AURA began searching for a site in earnest, concentrating on mountains in the southwest. Finally, on March 1, 1958, AURA secured a lease from the Papago Nation to use Kitt Peak in perpetuity to conduct astronomical research. NOAO and KPNO were born.

We're a mile from the Sun. Seriously, where is my sunscreen?

It's nice up here, though. Cool. Must be 7000 feet or so? No humidity; the temperature lapse rate must be huge out here, it's a lot cooler up here than down in the plain.

Wow, lookit all the telescopes! Mayall looks just like the Blanco telescope in Chile. And McMath... who came up with the design of that thing? There's WIYN... and the 2.1-meter... and...

Oh, hey, there's Baboquivari off in the distance. Black granite, millions of years old. Home of I'itoi, the Tohono O'odham creator-god. The center of the universe. As good a reference point as any, I guess.

Wow, look at all the telescopes...

There are five research telescopes controlled directly by KPNO, one teaching telescope at the visitor center, and five solar telescopes controlled by the National Solar Observatory, another division of NOAO. There are another 13 telescopes controlled by various universities and organizations, bringing the total to 24, one of the highest concentrations of telescopes in the world. The largest is the Nicholas U. Mayall Telescope, with an aperture of four meters. It sits just below the highest point on Kitt Peak, and dominates the landscape of the mountain. The tower and dome are 18 stories tall, and the primary mirror alone weighs 18 tons. The 4-meter has an interesting design. It's an f/2.7 Cassegrain on an equatorial mount, and the equatorial mount means the telescope is huge, and the dome that contains it is absolutely cavernous; most modern telescopes of that aperture have alt-azimuth mounts which save on weight, space, and cost. But the Mayall was built before computer controls and guiding made large, research-quality alt-az telescopes feasible. Like many telescopes, the mount sits on a concrete pillar separate from the dome's foundation to minimize vibrations in the scope when the dome is opened or moved. The Mayall Telescope was dedicated June 20, 1973, though first light was in March of that year.

The telescope dome is accessible by visitors to the site. There's an enclosed exterior observation deck which gives a beautiful view of the Arizona landscape, and there's a viewing gallery that looks into the dome itself. You should visit early in the day, as they will turn the lights out in the mid-afternoon when they start to cool the telescope down and begin instrument calibrations prior to the evening's observations. Unfortunately, the telescope, observing floor, instrument, and control rooms aren't accessible unless you're actually observing (or else you really know somebody).

The other notable resident of Kitt Peak is the McMath-Pierce Solar Telescope, which had first light in 1962. The design is by far the most distinctive on the mountain. It is in the shape of a right triangle, with the mirror sitting on top of the 100-foot vertical tower. The beam from the mirror is directed down a 200-foot shaft (the diagonal of the triangle) which goes below ground. The instrument room lies at the bottom of the shaft. The telescope is called a heliostat because the mirror itself follows the Sun, so the reflected beam remains stationary within the shaft. You can view the mirror and the shaft from a (very) small observing room at the ground-level entrance to the diagonal shaft, and you may also walk down the road to the entrance to the observing room. You may view the instrument room from the hallway, and you may be invited in for a quick tour if the telescope operator or research scientist is so inclined. Bring sunglasses -- they'll help if they have an image of the Sun projected in the room.

The earliest of the NOAO telescopes on the mountain was the 0.9-meter (36-inch) telescope, dedicated on March 15, 1960. (See the May 1960 Sky & Telescope v.19, n.60 p.392-397 for pictures.) The 2.1-meter telescope was already under construction at the time, and was completed in 1964. Several other telescopes have been built since, both by NOAO/NSO and by other universities. Notables include the 3.5-meter WIYN (Wisconsin-Indiana-Yale-NOAO) and 2.4-meter MDM (Michigan-Dartmouth-MIT) optical telescopes, Steward Observatory's 2.3-meter Bok telescope, and the NRAO 12- and 25-meter radio telescopes. There's even a 1.2-meter private telescope on Kitt Peak, called the Calypso Observatory, built by millionaire Edgar O. Smith.

What a beautiful sunset. Crystal clear. Was that a green flash? I think you were imagining it. What perfect dark skies. Absolutely beautiful. Is that the zodiacal light? I think it is! May I borrow your binoculars? They're opening up the visitor center 16-inch now. Neat, it's a Ritchey-Chretien! Wow, Jupiter is amazing! I can see the colors in the cloud bands. I'm not used to observing from this latitude, I hardly know my way around at low declination. Boy I wish I had time on the 4-meter tonight. Oh we have to go back now oh no it's only 10 o'clock it seems like we just started observing can't we stay oh man I don't want to go back to Tucson!

If you'd like to visit Kitt Peak, you'll need a car. It's a little over 50 miles from Tucson, and you have to go up another 12 miles of winding road to get to the top. Once there, there is a small but nice visitor center. During the day, you are welcome to walk around the mountain -- the roads are well paved and secure. Just be aware that people will be sleeping in the apartments on the mountain, so please be quiet, and obey the posted signs as to whether you're allowed entry into specific buildings. I think you're allowed to go up to the 4-meter and I know you can view the McMath-Pierce telescope on your own, but the rest of the telescopes will require a tour. There are guided tours of the telescopes periodically throughout the day; they are free but guides appreciate small donations. There are no public dining facilities on the mountain, but you are welcome to bring picnic lunches. There are vending machines and water available, and rest rooms in the visitor center. Bring sunscreen and a camera, you'll need both. The mountain closes to the public at 4PM, but if you book in advance you may stay on the mountain for evening observing. There is a fee associated with nighttime observing sessions, between $31 and $36 per person. But it's worth it; in good weather the skies are dark and crystal clear on top of the mountain, and the 16-inch visitor center telescope provides beautiful views of whatever strikes your fancy. There are also occasional public programs separate from the night time observing program.

If you are interested in doing research rather than just visiting, time on all NOAO-controlled telescopes is awarded on a competitive basis. The time between proposal submission, acceptance/rejection, and actually going and observing is between four and ten months. NOAO schedules time in six-month blocks (e.g. 2004A and 2004B for February-July and August-January). Proposals are reviewed by a time allocation committee made up of professional astronomers, and time is awarded on the basis of scientific merit and feasibility. Typically observing is done by professional astronomers affiliated with universities or other research organizations, but the proposal process is open to all US citizens/residents. All you have to prove is the scientific merit of your idea and your ability to carry out the research.

That was fun. Now I want to come back and do science... when are proposals due again?

Edmondson, F.K., AURA and its US National Observatories, Cambridge U. Press, 1997
Krisciunas, K., Astronomical Centers of the World, Cambridge U. Press, 1988
Marx, S. & Pfau, W., Observatories of the World, Van Nostrand Reinhold, 1982

I visited Kitt Peak last year during a conference in Tucson. It was fun playing tourist for once. The italicized lines above are my reminiscences.

For Lometa.