Sky & Telescope November 1988 [antikvár]

FOCAL POINTThe Amateur Astronomer's "Vast Alliances"IN HIS JOURNAL for 1851, Henry David Thoreau recorded an event so slight that few people would have bothered to write it down. As he lay on his back under the night sky, he saw a star pass behind the stem of a tree, proving that the Earth moves, "proving it better for me than a rotating pendulum," he wrote.In the sciences of the Earth and sky, Thoreau was an amateur in the original meaning of the word: one who loves. He did not watch the sky to confirm or confound some theory or other, but to experience the universe that he inhabited. In the passing of a star behind a stem of a tree he experienced the turning Earth.The statement that the Sun is 93 million miles distant never made any impression upon him, Thoreau tells us, because he never walked it. He did not neglect such information, but the experience of those many millions of miles is to be valued infinitely more than the memorization of the fact.Amateur astronomers share that felt need to experience. What unites us is the am- in amateur, the iove of the experienced night.It has been suggested that the root of the Latin word for love, am-, had its origin in baby talk, like yum-yum or mmmm! an expression of delight. And that's what propels us into the night when everyone else is settled down indoors. We seek the mmmm!, that special moment when we experience something a new comet, a meteor shower, the brightening and fading of a variable star, an astrophotograph of special beauty, an eclipse and suddenly, like Thoreau, we feel the Earth move.Each of us had an occasion when the passion for participatory astronomy was ignited. For me it occurred one evening many years ago as I watched an almost-full Moon through a telescope. Suddenly a flock of geese passed across the lunar disk. It was as if I had caught the birds somewhere out in space, winging their way from the Earth to the Moon. I experienced the third dimension of space in a way I never had before and felt the depth, theabyss. The mmmm! of that evening has never passed.Any one of us could go on recounting the rewards: the spooky color of the Moon in eclipse, a bolide of exceptional brightness, a faint nebula seen for the first time, the short streak of an asteroid on a photograph, the zodiacal light.Amateur astronomy is not a thing ofpomp and dazzle. I have often shared something seen through a telescope Uranus, Comet Halley, the Andromeda galaxy only to have my uninitiated companion ask disappointedly, "Is iitat it?" There are no Big Bangs in amateur astronomy. We make our universe of faint lights and imagination.I recall one evening in the spring of 1976 when Mars occulted the 3rd-magni-tude star Epsilon Geminorum. Mars occults a star of this brightness only once every 400 or 500 years. With my binoculars 1 watched as the planet approachedthe star. Wanting to share the beauty of these two objects in close proximity, I went off to fetch a friend. When we looked again the star was gone, like a disappearing coin in the hand of a magician, a trick of celestial legerdemain.It was a simple thing, this business of the planet hiding the star. But I knew that Epsilon Geminorum is a supergiant star, more than 100 times larger than the Sun, and that Mars is smaller than the Earth. Some long, thin triangles passed across my mind's eye, and in the few minutes that I watched the occultation I walked the light-years that separate the stars. It was a walk that made Thoreau's 93 million miles seem a mere step.My dictionary of English usage tells me that the word amateur has acquired "a faint flavor of bungling and a strong flavor of enthusiasm." What? Many of the amateurs I know have the skill and resourcefulness of professionals.For myself, I won't protest the faint label of bungler. I wander through the sky with no fixed purpose, seeking those serendipitous conjunctions of knowledge and delight that occur now and then a flock of geese against the Moon, the rare occultation of a star when I experience in a personal way some new dimension of the universe. That makes me, I suppose, an amateur amateur, but I will therefore lay claim to a double measure of enthusiasm.Thoreau was a bit of a bungler when it came to astronomy, but he bungled enthusiastically into some spectacular corners of the universe. The stars twinkled in the branches of the pines at Walden Pond; he knew them by name. He walked at night, he wrote, "with vast alliances." And we walk with him. With him, we are lovers of the night, amateurs in the original meaning of the word.CHET RAYMORaymo is a professor of physics and astronomy at Stonehitl College in Massachusetts, a weekly science columnist for the Boston Globe, and the author of several popular books, including Soul of the Night and 365 Starry Nights.Focal Point invites contributions from read-ers who wish to comment on contemporaryissues in astronomy and space science.