Small steps and giant leaps: lunar cratering theory from Galileo to Neil Armstrong
Three hundred years after craters were discovered on the moon by Galileo's first telescope, American astronomer T. J. J. See presented evidence favoring an impact theory of lunar cratering. Although See's arguments were not entirely original, he was the first professional astronomer to put forward an internally consistent impact theory. Despite the fact that the impact theory had been broached almost 250 years before, that See's version was consistent with both contemporary observation and his own overall theory of the formation of the solar system, and additionally that the impact theory today is considered to be the 'true' explanation for lunar craters; astronomers retained an almost unquestioning loyalty to one form or other of volcanic cratering theory. A few months after the publication of See's proposal the Director of the Lunar Section of the British Astronomical Association stated that the impact hypothesis was of such little consequence that it was only the eminence of Dr. See which bound him to argue against it. This pronouncement was representative of mainstream astronomical thought in the early twentieth century. It was, primarily, due to something very much like a scientific paradigm that had been established in the branch of astronomy devoted to the study of lunar surface features.;The existence of such a paradigm, as well as the inherent factors in the origin and development of the volcanic theory that contributed to its paradigmatic status, are examined in this work. It will also examine the question of why the equally explanatory impact theory had such difficulty in challenging its dominance even though they were both first articulated at the same time. Indeed, the origin and persistence for over three hundred years of the volcanic theory owed as much to a priori reasoning and aesthetic appeal as it did to observational evidence.;The examination of lunar cratering theory from the early seventeenth century to the last decade of the twentieth century provides a unique perspective on the structure and development of theoretical scientific change.