Temples in the sky.
THEY ARE FAR from civilization, invisible to most mortals, sometimes perched on inaccessible summits or lost in remote deserts. By the waning twilight or pale glare of the full Moon, it is easy to confuse their silhouettes with the temple of Angkor Wat, the mausoleum of the Taj Mahal, or the church of Cathares at Montsegur. Like temples of knowledge, curiosity, and reason, they stand motionless and proud above the clouds of Earth.
Astronomical observatories fascinate us. Who has not dreamed of viewing the planets at 1,000X in the perfect seeing of Pic du Midi? Who among us has not been wafted in our imaginations to the summit of Mauna Kea, where, on a cold summer's night, the sky of our galaxy resembles that evoked by Isaac Asimov in his famous Foundation cycle?
Observatories have given me much. In 1979, as a modest amateur astronomer of 20, I had a chance to work with Audouin Dollfus at Pic du Midi, helping confirm the existence of Saturn's almost mythical E ring. (It had first been suspected a dozen years earlier by Walter A. Feibelman.) The weeks and months spent in that eagle's nest, a splendid sanctuary of science, helped me discover two passions: photography and, yes, observatories.
Since then I have largely foresaken my 8-inch Schmidt-Cassegrain, hypering tanks, and my own pursuit of the Orion nebula, Stephan's Quintet, and Seyfert's Sextet. Instead I've focused my cameras on the places where astronomers of today actually try to make sense of the universe. I've sought out places whose exotic names are entwined with the scientific quests of our time: Mauna Kea and Calar Alto, Narrabri and La Palma, Siding Spring and Palomar....
While touring the world to see these temples in the sky, the "defining moment" came for me in the predawn hours of July 11, 1991. At 7:28 a.m., on the summit of the Mauna Kea volcano, lost with several other privileged individuals amid the volcanic cones and infinite cinder slopes, I lived an ideal instant in the life of an astronomer. As we sat among the domes of the world's premier telescopes, above the sea of clouds that dispensed their warm rain on the island of Hawaii below, the Moon and the Sun met each other in the sky and stopped. Witnessing that sublime spectacle, I sensed that Nature herself was paying homage to the astronomers who wanted to unlock her secrets.
In some far corner of the world, at an observing station whose exact spelling no one can remember, there is at this moment a night assistant or engineer, cup of tea or coffee in hand, peacefully turning the pages of Sky & Telescope before returning to the dome or going to bed. I hope such dedicated practitioners will pardon me for ignoring their modest equipment in this "travel notebook." Obviously I couldn't visit all the world's observatories. I chose, as children do, the biggest and most beautiful, the highest, and those where the greatest telescopes of all are found.
This installment touches on the grand observatories of the Southern Hemisphere; future ones will visit Europe and North America. Our journey begins under the Southern Cross and Alpha Centauri, between Carina and Sculptor, in the deserts that border the Chilean Andes.
AT ONE TABLE everyone is speaking Italian and French. Over at another it is German and Spanish, while everywhere a little bit of English is heard. The canteen of the European Southern Observatory is truly an astronomical Tower of Babel! The different cultures group themselves naturally at the evening meal.
Ritually, as she does every night, a young Chilean employee moves along the great bay windows that look out on the desert and slowly draws the blinds. As soon as night falls, no light must filter outside.
The faces reflect different lifestyles. Bjorn, who has observed all day long with the 15-meter radio telescope, looks tired but still wide awake as he begins to attack his steak. Patrice, about to spend all night with the 3.6-meter reflector, has just gotten out of bed and dunks his buttered toast in his cafe-au-lait. These are astronomers, crossing in the twilight....
Outside it is now truly dark. Vague silhouettes of domes open out on the depths of space. Furtive noises are heard, of foxes and viscachas (chinchilla-like rodents). An Italian astronomer is suddenly startled upon approaching his dome: in the fine pencil of light from his lamp he has perceived a tarantula as big as his fist.
At La Silla there are three telescopes of 2.2- to 3.6-meter aperture, but this astronomer (like you and me perhaps) will spend his night with the smallest telescope at the observatory, just 50 centimeters (20 inches) in aperture! High in the sky, perfectly obvious to the naked eye, shines the globular cluster Omega Centauri.
A FLOCK OF CONDORS wheels above the mountain, casting great shadows like hang-gliders on the striking domes of Cerro Tololo. Here is one of the most stunning astronomical sites on the planet. The mountaintop has been bulldozed flat, and the domes sit on an acre of concrete! Seven domes, each 10 to 40 meters high, are shoved almost one against the other, dazzling white as snow.
Strange impression: Am I on a heliport, in a parking space at a drive-in, or at some new-age megalithic site? The architects of Cerro Tololo must have been mystics. Their observatory seems almost to have been conjured up by sorcery, like some Manhattan Project in the sky....
On nights of a full Moon, when fog invades the Rio Elqui valley below, the observatory appears to "float" between sky and Earth. This rigorously flat platform, where domes gleam like ghostly totems in the moonlight, seems to belong to our planet no more.
Over here, a red glow filters from the slit of the 1-meter telescope. There, an astronomer hurries out on the catwalk of the 4-meter reflector and casts a glance at the always-clear Andean sky.
FOR 10 YEARS! The family of Francisco Gomez Cerda has spent 10 years working at the summit of Cerro Paranal. From 1983 to 1993 these Chilean meteorologists have been ferrying themselves to this bleak spot 2,700 meters up in the Atacama desert.
The place is indescribable. There is nothing here -- just vague knolls that belong to the coastal mountain range, plus a myriad of ochre, brown, and black rocks and rubble stretching off to infinity. Above, a sky eternally blue.
At the summit itself there is just a simple weather mast fed by solar cells, along with a minuscule 0.3-meter (12-inch) reflector. This instrument measures atmospheric turbulence automatically -- when there is any.
Marc Sarrazin, the French astronomer charged with the astrometeorological study of the site, is short of breath as he explains to me, "On some nights, the seeing hovers at around 0.2 arc second for several hours on end."
Odd sensation: Here is a mountain totally empty, nothing for 100 miles around, a sky of immaculate blue. But in just three years the first of four 8-meter components of the Very Large Telescope array will go into service here, a veritable "astronomy machine."
On the descent Cerda taps me on the arm: "Don't write that the weather is always good here. Two years ago, in midwinter, it snowed."
ELAINE SADLER makes her way toward one of the lesser domes on Siding Spring Mountain. She has negotiated the sinuous paths that plunge and climb sharply on the hills surrounding the observatory. Around her is a splendid forest, dotted with eucalyptus trees in which koalas hide. As a student, she first observed the southern sky with the very same 0.4-meter instrument she is now approaching.
Since her student days, the young astrophysicist has worked at many other observatories around the world. Later this evening, she will join colleagues in the enormous domed tower of the 3.9-meter reflector. It tracks the sky on autopilot, controlled from a room where neither the telescope itself nor the stars are visible. Dimly glowing computer screens and soft music from a CD player substitute for the ambiance of an Australian night.
For a time Sadler leaves the 0.4-meter dome and wanders to the crest of Siding Spring. Sunset over the basaltic "organ pipes" of the Warrumbungle Range is a sumptuous spectacle, and one eternally renewed.
DECEMBER IN AUSTRALIA. The stifling heat of summer has given way to the gentle languor of twilight, and silently the antennas of Narrabri's radio interferometer shift to a new target.
Multicolored birds perch and chirp from the small antennas of an old heliograph, inactive for many years. Out of the adjoining forest hundreds of kangaroos appear, in peaceful bands and family groups, to nibble at the prairie grass. They have grown accustomed to the slow movements of the great 22-meter umbrellas, paying them no heed.
While his radio-astronomer colleagues are busy collecting long-wavelength signals from faraway nebulae, John Davis is holed up in a laboratory a few kangaroo hops away. His own interferometer, dubbed SUSI, is optical. It measures 640 meters in length, is terribly complicated to point, and readies itself to observe the surfaces of stars....
When he's not off mountain climbing or pursuing photographic interests on some far continent, Serge Brunier edits Ciel et Espace, the popular French counterpart of Sky & Telescope.
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|Title Annotation:||The Far South, part 1; astronomical observatories in the Southern Hemisphere|
|Publication:||Sky & Telescope|
|Article Type:||Cover Story|
|Date:||Feb 1, 1993|
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