VOYAGES

The fog has lifted and the evening air hasstolen in, wrapping the mountain and thedesert below in a deep chill. Thirteen ofus, warmly dressed in layers although itis the middle of spring and the day washot, are huddled quietly around a smalltelescope in a drafty observatory, waitingfor our view of the cosmos. With a grind-ing rumble, the roof above us opens androtates slowly until a slice of night skyand a single bright point have been cho-sen. One by one we look: Venus, magni-fied about 130 times, appears as a slen-der, glowing crescent.

As the night darkens, more planets

and stars become visible, despite thebleaching glow of a full moon. We seeJupiter’s cloud bands—faint pink, likethe inside of a lady slipper shell—and twoof its moons, the binary star Castor,many star clusters, the blinding face ofour disruptive moon, some of the stars inthe Trapezium of the wispy Orion Neb-ula, and a spiral galaxy. For several hourswe watch the sky change as Earth turns.And twice we look at Saturn, unreal in itsbeautiful perfection, so solid and at thesame time so delicate. “This is prettymuch the best object in the sky,” saysFlynn Haase, an amateur astronomer

and this evening’s guide. “I usually keepit as the finale object.”

Haase is one of the leaders of theNightly Observing Program at Kitt PeakNational Observatory, which sits in theQuinlan Mountains on the TohonoO’odham Reservation in southwesternArizona. Nearly every evening as manyas 20 people can observe the night skythrough a 0.4-meter telescope at the sametime that astronomers from all over the

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The Universe atop a MountainGAZING AT THE COSMOS FROM KITT PEAK NATIONAL OBSERVATORY BY MARGUERITE HOLLOWAY

KITT PEAK is where dark matter and the first grav-itational lens—in which one galaxy bends light from a more distant one—were discovered.

Copyright 2001 Scientific American, Inc.

world are going to work at the muchlarger telescopes around the mountain-top. With 24 telescopes—the biggest ofwhich, the Mayall, measures four metersacross—Kitt Peak has the largest collec-tion of optical telescopes in the world.Some of them can be visited during theday, when the professional astronomersare asleep.

It is an eerie place, the top of this6,875-foot mountain. Quiet in the day-time because of the nocturnal researchers,quiet and pitch-black in the nighttime be-cause unwanted light or vibrations fromnoise can throw off the precise measure-ments and obscure the clear views need-ed to study the sky. The telescopes, mostof them housed in white observatories,cover the mountaintop like the buildingsof some luminous futuristic city. TheMayall, used to study dark matter andthe large-scale structure of the universe,stands on the highest promontory. Spreadbelow it on the 200 or so acres of the sum-mit are the 2.1-meter telescope that dis-cerned the first pulsating white dwarf, the3.5-meter WIYN telescope, which sits inan octagonal building that is freely venti-lated to remove the image-distorting heatof the day, and the McMath-Pierce SolarTelescope Facility, where the world’slargest solar telescope is found.

The telescopes of Kitt Peak have con-tributed profoundly to our understandingof space. “But mostly it is not new thingsbeing discovered,” explains Haase, whoalso works at several of the telescopes.“Mostly it is to further understand things,to get the data to back up the ideas thatthey have already come up with in thelab.” Two of the telescopes are used forthe Spacewatch program: they scan theheavens for asteroids and in recent yearshave identified a few near-miss candidateshurtling toward us. All of this work isdone under the auspices of the Associationof Universities for Research in Astronomy,which, in turn, is under contract with theNational Science Foundation. Twenty-nine universities conduct research on site,and twice a year astronomers submit com-

petitive proposals for a chance to workhere—some may have to wait a year ortwo before they can come to gather data.

The public, however, is free to wan-der the grounds and in and out of threeobservatories. From the viewing room

next to the 2.1-meter mirror, you sensethe massiveness of the machinery neededto move the 60 tons of optical equip-ment, and you can see the small room be-hind the telescope where the astronomerssit at their computers, downloading data.

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In the McMath-Pierce solar telescope ob-servation room, you can look down the135-meter shaft that runs parallel toEarth’s axis and see the different mirrorsthat ultimately resolve the image of thesun to one that is about a meter wide,easy for astronomical study.

Although the equipment is impressiveand the tours informative, it is hard to geta sense of how the real work of as-tronomers is conducted. But at the Night-ly Observing Program, you can at leastexperience how most astronomers usedto work—with the naked eye—and canunderstand why the vast, mysteriousbeauty of the cosmos drives them to buildsilent, domed cities on the top of moun-tains in the middle of deserts.

The observatory is open to visitorsmost every day from 9 A.M. until 3:45P.M., and guided tours (for $2) are offeredat 10 A.M., 11:30 A.M. and 1:30 P.M. The56-mile-or-so drive to Kitt Peak takesabout an hour and a half from Tucson.The easiest route is I-10 to I-19 to Route

86. But the more beautiful route—espe-cially when it is spring and the desert is infull, fragrant bloom—is west through thesurreal, saguaro-studded Tucson Moun-tain Park and then down Kinney Road toRoute 86. Further information aboutKitt Peak can be found at www.noao.edu/kpno/

For more information about the

Nightly Observing Program, which be-gins 45 minutes after sunset, go to www.noao.edu/outreach/nop/ or call 520-318-8726 well in advance for reservations(there are about 4,500 visitors a year).The cost is $35 for adults; $25 for chil-dren, students and seniors. The driveback to Tucson from Kitt Peak when it isdark can be as chilling as the night air, sobe careful: the road through the SonoranDesert is lined with crosses and altarsmarking the sites of fatal car accidents.

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McMATH-PIERCE solar telescope’s optical shaftruns underground, parallel to the axis of Earth.

VOYAGES

Copyright 2001 Scientific American, Inc.