National Geographic : 1970 Aug
Exploring the Heavens With the Society's New Map ACROSS THE SPANGLED CHASM of space, from as far away as the most distant glimmer the eye can see, the National Geographic's map The Heavens brings the magnitude of the celestial canopy as close as the observer's backyard. The Society's revised sky map, distributed with this issue of the magazine,* appears as the world's attention turns again to the time less panorama of the heavens-drawn there by new adventures in space. Your Society first published a sky chart 51 years ago, in the pages of the NATIONAL GEOGRAPHIC MAGAZINE, and distributed the first wall map of the heavens as a special sup plement in 195 7. To meet continuing demand, the map had to be reprinted twice. Because of soaring interest in space, and because the Society's membership has grown greatly, the map has been revised for a sec ond distribution with the magazine. The orig inal version went to 2,200,000 member-fami lies; the new one will reach 6,800,000. Charts Depict the Changing Show The two "hemispheres" of the map show the skies as they appear from the North and South Poles of Earth. Observers in lower latitudes do not see all the stars in one of these hemispheres at any one time, of course, or even identical celestial arrangements at the same hour week after week. Around the hemispheres, the names of the months indicate when the stars in each seg ment of sky are brought into prominence by Earth's annual journey around the sun. Our planet's daily rotation on its axis also changes the heavenly picture, obscuring some stars in sunlight while others parade past by night. Earth's turning seems to spin the constella tions near the poles of the celestial canopy in orbits of their own, while causing stars in lower latitudes to appear to rise and set. The charts on the reverse side of the map, designed by Dr. Donald H. Menzel, former Director of the Harvard College Observatory (see "Solar Eclipse, Nature's Super Spectacu lar," page 222), show the positions of the ma jor stars and constellations for viewing in every month, from various latitudes. Of course no map could display more than a fraction of the hundred billion stars of our galaxy, the Milky Way-or the quadrillions of suns shining in the millions of galaxies vis ible in powerful telescopes. Of the 6,000 or so stars the unaided eye can see, the map shows 1,971 of the most apparent, especially those that form the 88 constellations. A strip map depicts the constellations of the zodiac, that band of sky centered on the ecliptic, the plane of Earth's orbit around the sun. Above the zodiac, a panel tells where the planets visible to the eye may be seen during the next three years. Artist Aided by Photographs From Space Illustrator Jay Inge, a member of the Socie ty's Cartographic Division, painted the pic tures of Earth, Earth's moon, and the planets Mars, Jupiter, and Saturn. He used photo graphs transmitted from Mariner spacecraft 6 and 7 to show the craters of Mars as we now know them; photographs from the Apollo missions guided him in painting Earth as our planet appears from space. The stargazer who takes out his map on a clear night to study the heavens joins a fra ternity of the mind chartered at the dawn of history. The Chinese, Egyptians, and Baby lonians had discerned method in the seeming celestial madness more than 2,000 years before Christ, establishing astronomy as one of man's oldest sciences. Now moon-voyaging astronauts and physicists plotting spacecraft flights to the planets turn again to astronomy to carry out man's boldest explorations. Except for a select few, space travel re mains-in our era-a vicarious adventure, lived through televised images and the crackle of voices across the ethereal chasm. Still, the heavens belong to everyone who gazes at their glittering display and seeks his own answers to the riddles there. The fraternity of star gazers, ancient and honorable order, remains, as ever, open to all. *Additional copies of the map The Heavens, and other wall maps of the Society, may he ordered by mail from Dept. 61, National Geographic Society, Washing ton, D. C. 20036. Prices include postage and handling: $2.15 on paper, $3.30 on plastic (unfolded).