Such instruments proffered fleeting glimpses of planets and stars that, like the dance of the seven veils, only aroused a burning desire to see more. In the Netherlands, the Huygens brothers unveiled lanky telescopes that had no tubes at all: The objective lens was perched on a high platform in a field, while an observer up to 200 feet away aligned a magnifying eyepiece and peered through it. In Danzig, Johannes Hevelius deployed a telescope 150 feet long hung by ropes from a pole, it undulated in the slightest breeze. Subsequent observers took the design of glass-lensed, refracting telescopes to great lengths, sometimes literally so. Large light-gathering lenses were not yet available, so he concentrated on making longer telescopes, which produced higher magnifying powers and reduced the halos of spurious colors that afflicted glass lenses in those days. Evidently the Earth was a small part of a big universe, not a big part of a small one.Īnd soon, sure enough, Galileo went to work making bigger and better telescopes. Galileo’s telescope revealed so many previously invisible stars that when he tried to map all of them in just one constellation, Orion, he gave up, confessing that he was “overwhelmed by the vast quantity of stars.” He saw mountains on the moon-in contradiction to the prevailing orthodoxy, which declared that all celestial objects were made of an unearthly “ether.” He charted four bright satellites as they bustled around Jupiter like planets in a miniature solar system, something that critics of the Copernican sun-centered cosmology had dismissed as physically impossible. Galileo, who first trained a telescope on the night sky 400 years ago this fall, pioneered this two-step program. Second, you soon want a bigger telescope. First, you are astonished by the view-Saturn’s golden rings, star clusters glittering like jewelry on black velvet, galaxies aglow with gentle starlight older than the human species-and by the realization that we and our world are part of this gigantic system. When you start stargazing with a telescope, two experiences typically ensue. This story appears in the July 2009 issue of National Geographic magazine.
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