Temples in the sky.
Astronomical Europe is multifaceted. Ever since those famous nights of 1610 when Galileo Galilei pointed his 1-inch telescope into the sky over Florence, this continent's science has been shaped by diverse cultures, scholars, kings, and weather conditions. In England, Germany, or the Netherlands, for example, where the skies of Cornwall or Westphalia yield fewer stars than the sky over the Spanish Sierra Nevada, radio astronomy reigns. In France the discovery of the solar system has taken center stage, thanks to the sublime terrace of Pic du Midi. And Spain, for its part, maintains modern and majestic international observatories under the forever blue skies of Andalucia and the Canary Islands.
There are many more European observatories than I can list in this second installment of "Temples in the Sky." To be thorough, I would have to explore the age-old megaliths of Stonehenge, Karnak, and Uraniborg, and visit the great refractor of Meudon, where Eugene Antoniadi learned that Percival Lowell's Martian canals were only an illusion. We would also travel to the great dome at Berlin where Johann Galle discovered Neptune. And there's more. Since Europe is so rich in observatories, I would have to mention Greenwich and Paris, Westerbork and Jodrell Bank, Onsala, Tautenburg, Zelenchukskaya. . . .
Nevertheless, I hope that this second travelogue will acquaint you with some of the most prominent observatories of the old continent. Here lived Kepler, Tycho, Galileo, Copernicus, Newton, Herschel, Le Verrier, Foucault, Cassini, Encke, Lord Rosse, Lyot, and so many other astronomers before us. Some pondered the sky's geometry; others surveyed its fabric, arc second by arc second, as if they were studying a square foot of prairie with a magnifying glass. Their common ambition: to understand the whole universe.
PIC DU MIDI
RENE GOUZY has been ranging through the passageways of the Pic du Midi Observatory for more than a week now. He knows by heart the dimly lit hallways and the too-steep stairways (at 2,876 meters altitude, one's breath is a bit short). Pic du Midi suggests a strange mixture of old and new -- a cross between the Maginot Line, the Paris metro, and a monastery. While this century-old fortress stands firmly against the fogs and storms of the Atlantic, even the meter-thick walls and double-pane windows blocked by draperies of stalactites are barely enough. The observatory trembles under violent attacks of wind.
Today at twilight the wind has slackened, and the building is entirely buried under snowdrifts. Through the only door that opens to the outside, Rene has been able to get out onto the terrace of the mythic 1-meter telescope. First the velvety blackness of fog veils all, and the powdery snow blows with suffocating intensity. Then, abruptly, the Pic emerges from a sea of clouds. Like an island lost in the heavens, the observatory, resplendent with snow, glitters in the last fires of sunlight. The air is now brutally cold, dry, and transparent as crystal. In a temperature of -15|degrees~ C, Rene admires a panorama of Europe and awaits the setting Sun's green flash. He already knows that the night will be exceptional.
NICOLA SCHNEIDER carefully arranges her skis against the old wooden rack. She begins preparing for a dinner of raclette with Fendant, the famous Swiss white wine. The young German astronomer still has an hour to go before relieving one of her two colleagues. They are creating a millimeter-wavelength sky map using the University of Cologne's 3-meter antenna.
The atmosphere of the hotel is reminiscent of the '30s -- a bit out of date, too large for the rare customers who have strayed far above the village of Zermatt to this spot. The observatory of Gornergrat occupies two high towers that sit atop the hotel of the same name.
In this Swiss region of Valais, astronomers like Nicola can enjoy some of the highest, most dazzling, and rugged summits in the Alps. The skies here are without doubt among the clearest of Europe. In winter when all the water vapor is trapped by the Gorner glacier and the temperature falls below -25|degrees~ C, Gornergrat gets closer to the stars than even Mauna Kea.
Before going on duty Nicola will watch the Sun set behind the colossal peak of Mont Rose (4,634 meters high). To the west, the majestic and vaguely hostile silhouette of the Matterhorn dominates her view of the Zermatt valley below.
BEATING RAIN. Heavy clouds that cling to the pine trees of the Eifel mountain range in Westphalia, Germany. A narrow road that plunges into the night, and the headlights of a car that pierce the darkness with difficulty. The road descends, descends again, and winds around in a basin enveloped by fog where the icy rain persists.
Suddenly a loud, mechanical groan disturbs the night, and in front of the automobile, in a clearing, appears a brightly lit, phantomlike form. The giant radio telescope of Effelsberg has just turned several degrees and is getting ready to observe a new quasar. The German astronomers pay no attention to the weather; their telescope easily penetrates the fog, rain, and clouds.
On the side of a hill, 100 meters away in the control center, the telescope's pilot watches the movement of the gigantic machine. Columns of numbers scroll down the computer screen. Like Polyphemus (the Cyclops blinded by Odysseus), the engine observes without seeing QSO 1928+73, an anonymous quasar situated 10 million light-years from the Earth.
SEEN from the gardens and shady patios of the Alhambra palace, the Spanish Sierra Nevada shows its snow-covered summits. Rising out of the sweetness and incomparable light of the Andalucia region in southern Spain, its harshness seems incongruous. There, at the summit of Pico Veleta, tourists flock in T-shirts along the "highest road in Europe" and discover, at 3,392 meters, the dreadful side effects of climbing in high altitudes. In the cold and wind, they are seized with the desire to descend as quickly as possible toward the city of Granada and its inns where, late into the night, the Andalucians will debate and peacefully savor their tapas with glasses of sherry.
The scene is more austere on the buttresses of Pico Veleta where a 30-meter radio antenna is perched. In the station's restaurant, video monitors hanging from the ceiling tell the dining astronomers which region of the universe the antenna is picking up.
At wavelengths between 1 and 3 mm this instrument ranks as one of the most sensitive telescopes in the world. Year after year it detects new molecules -- in the atmosphere of Titan, on a passing comet, in the clouds of the Milky Way, or in some faraway galaxy.
Outside, evening has arrived in the desert. Up on Pico Veleta the silence is interrupted only by the deep and regular breathing of the vacuum pumps that maintain the giant antenna's "front end" at a temperature close to absolute zero. Toward the southwest, an astronomer courageous enough to face the cold of twilight can sometimes glimpse, across the Mediterranean, the distant snows of Morocco's Atlas Mountains.
THE MOON has risen on the Sierra de los Filabres, the great mountain ridge that rises above the desert of Almeria, Spain, where filmmakers rush from all over Europe to produce Westerns in fake ghost towns. The domes of Calar Alto, rose-colored in the twilight, will soon fade into the night.
In the large tower German astronomers prepare to position a splendid royal blue machine: Calar Alto's most powerful telescope. Built by Zeiss and put into service in 1983, the 3.5-meter reflector is the last of the "great elders," conceived in the image of the Hale telescope of Palomar Mountain. Henceforth, modern telescopes such as the MMT, NTT, VLT, and JNLT will give astronomical instrumentation a new image, more "Keck," more "high tech," but colder somehow as well.
At Calar Alto the large telescope peers out on infinity. Entranced by the hum of its clock drive, one can almost believe it has a life of its own. The astronomers and technicians depart the dome, leaving the monster alone. It continues to slew down toward the horizon, as if pensively searching for some invisible point in the sky.
FROM a distance, appearing very small in the east, the pyramid of Pico del Teide emerges from the clouds above the Atlantic Ocean. To the west, our gazes plunge into the frightening abyss of the Caldeira Taburiente, the "cauldron," vestige of an ancient volcano that has long since disappeared.
The ridge falls steeply down for nearly a mile, and at the cauldron's bottom, clouds blown in from the Atlantic accumulate in a haunting silence. To appreciate the observatory in its entirety, it is necessary to climb to the mountain's summit, the so-called Roque de los Muchachos.
On the sharp rim of the gigantic crater the observatory is the image of fragility itself. At the edge of the pit, the white domes that open onto the universe contain some of Europe's most powerful telescopes. At La Palma the Spanish, English, Irish, Dutch, Danes, Swedes, Norwegians, Finns, and Italians are attracted by the Astrophysical Institute of the Canaries, which offers them a welcome refuge: telescope time!
The 2,400-meter level on La Palma has been decreed a "world astronomical reserve" by the Spanish authorities. But no one warns a traveler that on the nights of the full Moon, the "muchachos" play in pale light. At the edge of the cauldron's abyss these goblins of basalt strike poses under the moonlight. Who would dare climb up there among them?
PICO DEL TEIDE
THIS observatory lies in one of the most beautiful astronomical settings on the planet. Its domes are set on 20- to 45-meter towers and evoke, irresistibly, the minarets of some temple to the Sun from the Arabian Nights. Off to one side, like a proud pyramid, Pico del Teide itself rises 3,718 meters above the Atlantic Ocean. This large volcano is Spain's highest summit.
But are we still in Europe? At 28|degrees~ north latitude, Tenerife faces the Sahara Desert, whose sand, lifted by storms, sometimes comes to caress the neighboring desert island of Lanzarote. Tenerife belongs to the archipelago of the Canaries, which is to Spain what the Hawaiian Islands are to the United States. Like the archipelago of the Pacific, the Canaries comprise seven principal islands overrun by tourists. And like Hawaii, the Canaries have two islands dominated by large volcano-based observatories, unreal terraces in the sky.
Photojournalist Serge Brunier lives in Paris and is the author of several scientific books. He worked in the 1980s with Audouin Dollfus at both Meudon and Pic du Midi observatories.
At 2,876 meters altitude, this French observatory stands as a living monument to the efforts of astronomers who seek to uncover the secrets of our solar system. Established in 1878, Pic du Midi today features reflecting telescopes of 2-meter, 1-meter, and 60-cm aperture, several coronagraphs, and a 50-cm solar refractor. The best images of the Sun, the Moon, and most of the planets ever taken from the Earth have been captured at Pic du Midi.
Two turrets shelter an Italian 1.5-meter infrared telescope and a German 3-meter millimeter-wave dish, both of which are installed atop a hotel 3,150 meters above sea level. The observatory of Gornergrat belongs to the Jungfraujoch Foundation, which also maintains another Swiss high-altitude station, the Sphinx Observatory at 3,580 meters.
This fully steerable radio telescope, the most powerful on the planet, observes the universe at wavelengths between 1 cm and 1 meter. It is 100 meters in diameter and has a moving weight of 3,200 metric tons. The radio telescope of Effelsberg, in service since 1972, can be used either as a single instrument or as an element in a very-long-baseline-interferometry array.
This station belongs to IRAM (Institut de Radioastronomie Millimetrique), a Spanish, French, and German institute that also administers the submillimeter interferometer of Plateau de Bures in the French Alps. The 30-meter antenna of Pico Veleta lies in the Spanish Sierra Nevada at 2,850 meters altitude. It and the Nobeyama 45-meter dish in Japan are the world's best antennas for studies at millimeter wavelengths.
This German-Spanish facility is the most important observatory in old Europe. At 2,160 meters altitude and north latitude 37|degrees~, it operates 3.5-, 2.2-, 1.5-, and 1.2-meter reflectors as well as an 0.8-meter Schmidt telescope. The 2.2-meter instrument has a southern twin at La Silla Observatory in Chile.
Without doubt, La Palma is the great European observatory of the future. The stability of the air is at least as good as in Hawaii, and the Swedish solar telescope is currently the only one to rival that at Pic du Midi. Among the greatest reflectors already installed at La Palma are the 4.2-meter William Herschel, the 2.5-meter Isaac Newton, and the 2.5-meter Nordic Optical Telescope. In the planning stages are the 3.6-meter Galileo and the 2.5-meter Large Earth-based Solar Telescope.
At 2,400 meters, this is above all a European solar observatory managed by the Astrophysical Institute of the Canaries. In several years, with the installation of the 90-cm Themis telescope, this station will be the world's greatest center for the observation of our star. Currently the principal instruments are four solar telescopes of 25-, 40-, 45-, and 60-cm aperture; a helioseismograph; and four reflectors of 50-cm to 1.5-meter size.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||The Old Continent, part 2; high-altitude observatories in Europe|
|Publication:||Sky & Telescope|
|Date:||Jun 1, 1993|
|Next Article:||In search of a good binocular mount.|