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compromise its main Jupiter mission nearly a year and a half later. Quite aside from the technology involved, two different ways of identifying the twenty-one fragments had evolved. One used letters, the other numbers, and they reversed one another direc- tionally, with the letters moving from east to west, and the num- bers from west to east. That meant that a single fragment would have two designations, such as Q and 7. The media eventually solved that problem by ignoring the numbers. The letter system made more sense even to many scientists, since it had been used to designate the pieces of Periodic Comet Brooks 2 as far back as 1889. There was a great deal of debate about the actual size of the fragments, which would affect the force of the impacts and the amount of energy released as they struck the planet. Knowledge about the lower layers of Jupiter s strange atmosphere and its supposed metallic core was limited, largely a matter of specula- tion based on computer models, which was exactly why Galileo had been dispatched to study it. There were thus three scenarios about what might happen, with one suggesting impact flares so huge and so bright that they might be seen from Earth without a telescope, while the other two held out far less hope of a great visual show, either because the comet fragments would disinte- grate too high in Jupiter s atmosphere, or would be dragged into such depths that little evidence of disruption would appear on the surface. 42 It Doesn t Take a Rocket Scientist The range of possibilities had David Levy extremely excited one week and quite discouraged another, and the Shoemakers went through similar ups and downs. Conflicting information continued to pour in, including Hubble data in September 1993 and March 1994 indicating that the fragments Q and P had split apart into smaller units. Did that mean that the whole train of comet fragments might disintegrate even before impact? The media began to downplay the possibilities of any spectacle, then reversed course as the July 1994 impact date approached. The major magazines, television networks from CNN to the BBC, and, of course, science magazines of every stripe all wanted interviews. Levy had two new books coming out, The Quest for Comets and Skywatching, and began a cross-country lecture tour at the beginning of April that had burgeoned into nearly a hun- dred talks, as well as book signings. On May 17, Shoemaker- Levy 9 showed up on the cover of Time. The hype was on, and some scientists tried to cool down public expectations by em- phasizing the possibility of a complete fizzle. The Shoemakers and Levy were almost relieved when the arrest of O. J. Simpson for the murder of his former wife grabbed the headlines in mid- June. Perhaps they d get a bit of breather before the collision a month later. The experience David Levy was undergoing was an unusual one for an amateur scientist. It lies at the opposite extreme from the disinterest and neglect that attended Gregor Mendel s break- through discoveries about genetics. Mendel s experiments with peas consumed nine years of painstaking work and original thinking, but the two lectures he eventually gave on the subject were heard only by a small group of local dignitaries, and the published paper containing those lectures was largely ignored for thirty-five years. David Levy, on the other hand, had a vast national, and often international, audience paying close atten- tion to what he (and the Shoemakers) had to say about the comet they had discovered. Part of the difference, of course, is David H. Levy 43 due to modern communications, particularly television, which could not only bring Levy live to a far-flung public, but also pro- vide computer graphics that made the upcoming collision be- tween the comet and the planet Jupiter vividly immediate. More crucially, Mendel was promulgating a new scientific concept, one that involved invisible processes, while Levy had discovered a new object, easily seen with a telescope. Throughout the history of science, new concepts have often been ignored or have met with active resistance by more established scientists. Charles Dar- win s theory of evolution was bitterly challenged, while Albert Einstein s first papers in 1905 were initially understood by almost no one except Max Planck. A celestial body that can be photo- graphed, like Shoemaker-Levy 9, doesn t run into such problems. There are also more subtle differences, and similarities, to be considered. Gregor Mendel s laboratory was a monastery gar- den and greenhouse not all that different a setting from the backyards in Canada and Arizona where Levy spent so many years peering at the night sky through small telescopes. Both men were curious about the natural world. There is some evi- dence that Mendel knew how important his work might prove, but in Levy s case it was more a matter of intellectual curiosity and personal satisfaction. To the extent that Levy expected to have an impact on the scientific world, it involved teaching chil- dren about astronomy. For two decades before the discovery of Shoemaker-Levy 9, he had been introducing groups of children to the wonders of the night sky, working with schools and local associations. He was very good at this kind of instruction, con- veying his own enthusiasm with ease and humor and knowing just how to phrase things so that young minds could grasp them. As the years passed, the fact that he himself had discov- ered a number of comets gave him great credibility with the children (and occasional groups of adults) whom he tried to turn on to the pleasures of astronomy. It was true that his dis- coveries had gradually gained him a serious reputation among 44 It Doesn t Take a Rocket Scientist both amateur and professional astronomers as a man with spe- cial gifts. But while he was a respected figure in the fairly tight- knit world of astronomy, and through his books was succeeding in reaching a wider audience, he was not in it for fame. Every amateur astronomer no doubt harbors a few fantasies about making a remarkable discovery, but they also know that it in- volves luck as much as anything else. Luck certainly played a considerable role in the discovery of Shoemaker-Levy 9. The comet had, after all, broken up on its previous journey around Jupiter, and someone else might have noticed what was going on then. In fact, there was another group, also working at the Palomar locale, that had taken pic- tures of the same part of the sky a week earlier. The comet was there, but it hadn t registered with this group, perhaps because its features were so odd as to suggest a mere flaw in the photos. On the night of March 23, 1993, when the crucial pictures had been taken by the Shoemaker-Levy team, the weather was so overcast that there was some discussion about whether the group should even bother to do anything. Levy s habitual enthu- siasm had been the factor that led the group to give it a try. There had also been a problem with the film to be used that night. Someone had opened the box of prepared film, spoiling the negatives. But Gene Shoemaker thought some of the film lower in the box might be all right, and it was. It is also worth emphasizing again that when Carolyn Shoemaker was going over the developed film two days later, she passed by the odd configuration once, and then went back. She could not quite believe what she was seeing, but both her husband and David Levy had agreed that they might indeed be looking at a squashed comet. They had then proceeded to report it on what was largely a hunch. The group that had ignored it or not seen it at all the previous week had been made of up of professional astronomers. Professionals get hunches, too, of course, but they may be less open to them than amateurs who have less to lose if they make a mistake. David H. Levy 45 Obviously, astronomy is a field that is particularly congenial for amateurs. You have to know what you re doing to discover a [ Pobierz całość w formacie PDF ] |