Adler Planetarium

Record breaking crowds have demonstrated their enthusiasm for the refurbished Adler Planetarium in Chicago with its new $250,000 Zeiss Mark VI projector, the most modern instrument of its kind in the world. This marvelous instrument reveals with new realism 9,000 stars, the sun, moon and planets, as well as meteors, comets, aurorae, the Milky Way, star clusters and other galaxies.

An extra show had to be scheduled opening day to accommodate the throngs that waited for "A New Look at the Universe" in the Planetarium's Sky Theater. Their enthusiasm can be attributed to the new Zeiss instrument, a complex mechanism containing over 160 optical projection systems, which gives spectators a dazzling view of the sky as it appeared thousands of years ago, or as it will appear in the future, from any position on earth. Without stirring from new chairs which tilt back for comfortable viewing, spectators can journey to any part of the earth—the North Pole, South Pole, or the Equator to see the skies as they would appear from these points on earth.

Fifteen major stars are matched to their special color characteristics. Another aspect of the new instrument that fascinates visitors is that it transports them through time and space in a controlled manner. They can move through a day in a period as short as 30 seconds or as long as 36 minutes. The duration of a year can be as short as 10 seconds or as long as 12 minutes.

Saturn and Jupiter can be seen as they appear to the naked eye or a binocular projector can zoom the viewer in to a magnification of 9 times to inspect greater surface details. There is "scintillation" or twinkling of stars not present before. The variability of brightness in individual stars is brilliantly displayed. The Star, Algol, for example, has variability in brightness due to an eclipsing system of a small star circling around it, cutting the degree of brightness from time to time. Delta Cephei, a pulsating star, has changes of brightness in itself, not caused by another body orbiting around it.

Manipulation of the Zeiss instrument can display 10 different types of eclipse possibilities. The March 7th eclipse can be shown as it appeared from Mexico and up the Eastern coast of the U. S., where a total eclipse was seen, as well as from Chicago, where only a partial eclipse was visible.

Clouds move at varying speeds in varying directions over spectators' heads. Twelve double projectors produce 12 different Chicago horizon scenes, and during sunset fade from daytime to nighttime skyline views.

For astrology buffs and other enthralled watchers all the constellations make a sudden, climactic appearance in the night sky: The Great Bear; Leo, the lion; Cancer, the crab; Gemini, the twins; Taurus, the bull; Aries, the ram; Pisces, the fish; Aquarius, the water carrier; Capricornius, the sea goat; and others.

For further information call WA 2-4488, or write 900 E. Achsah Bond Drive, Chicago, Illinois 60605. Groups desiring a special Sky Show to be given exclusively to their members can arrange such service for a nominal fee. A Sky Show on any astronomical topic with appropriate visual effects will be planned in consultation with a group representative.

Illinois Parks 94 May/ June 1970