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Despite all that has been learned about the dynamics of a comet's tail, its shape cannot be accurately predicted. In the late 18th century, DeCheseaux's comet sprouted seven distinct tails that fanned out peacock-like. Some comets do not develop tails at all. As of last week, however, Kohoutek was developing a classic appendage, which should continue to increase in length and grandeur until the comet comes close to the sun. Most comets survive this relatively close flyby of the sun and emerge, sometimes altered in appearance, with even more brilliant tails. Others, affected by the sun's powerful gravity, have broken up and vanished, as did the debris of Biela's comet after it split in two in 1846.
It was during a search for the remnants of Biela's comet that Luboš Kohoutek made his great discovery. Interested in the minor bodies of the solar system since boyhood meteor-and comet-hunting expeditions in the Czechoslovak mountains, he had in the fall of 1971 located a cluster of about 50 small asteroids in an orbit roughly comparable to that of Biela's comet. Last February, using Hamburg Observatory's 32-in. Schmidt telescope, he tried to "recapture" the asteroids, which he feels may be the remaining chunks of the lost comet. To Kohoutek's surprise, he not only obtained pictures of the asteroids but also, during an eight-day period, discovered on his photographic plates the telltale blurs of two new comets.
Such discoveries are not unusual; as many as a dozen new comets are found each year, often by diligent amateur stargazers like Kaoru Ikeya, a worker in a Japanese piano factory. Ikeya has been finding new comets at the rate of about one a year since he and another Japanese amateur, Tsutomo Seki, independently discovered the major Ikeya-Seki comet in 1965. Kohoutek, too, had previously discovered a comet in 1969. But it was the second of his 1973 discoveries —officially called Comet Kohoutek 1973f (the ∫ indicating that it was the sixth new comet sighted this year)—that quickly created worldwide excitement.
Dirty Coat. As is customary, Kohoutek immediately sent word of the sightings to the Central Bureau for Astronomical Telegrams at the Smithsonian Astrophysical Observatory in Cambridge, Mass. Under the direction of Astronomer Brian Marsden, the bureau acts as a world clearinghouse for news of astronomical discoveries. It soon became evident to Marsden that the second comet was no ordinary visitor from distant space. After making some rush observations of his own ("We spent a very tense weekend out at Harvard Observatory's Agassiz Station"), he reported that the comet Kohoutek had been sighted at a distance of roughly 480 million miles from earth, barely within the orbit of Jupiter. (Halley's comet, by contrast, was not found on its last approach until it was some 180 million miles closer to earth—even though astronomers knew where to look for it.) Never before had a comet been detected at such a great distance.