Astronomical Images : Second motion of the Earth according to Copernicus

Vincenzo Maria Coronelli

Astronomical Images

<p style='text-align: justify;'>In his <i>Atlante veneto</i> of 1690, Vicenzo Coronelli (1650-1718) included a discussion of the world systems of Ptolemy, Copernicus, and Tycho Brahe. Accompanying this discussion of the 'Sistemi del mondo' were nine figures, presented together on a single bifolium (Plate 9); these figures were later reproduced in Coronelli's <i>Epitome cosmografica</i> (1693), where they were each printed onto a separate sheet. Eight of the figures are explicitly labelled as Figures I to IV and VI to IX; by inference, the fifth figure, seen here, is Figure V, although it consists of four miniature diagrams themselves labelled as Figures I to IV. This series of smaller images purports to illustrate the reasons given by Copernicus for the second motion of the Earth ' its annual motion beneath the ecliptic. Figures V.I and V.II depict the orbiting Earth in relation to the inferior planets, while V.III and V.IV emphasise its relationship to the superior planets. The corresponding texts adduce the different appearances of the inferior and superior planets, the limited elongation of the former from the Sun and the planetary stations and retrogradations, as evidence for the annual motion of the Earth. The inclusion of planetary models in these cosmographical works reflects the development of the genre in the early modern period. In attempting to describe the Earth in relation to the heavens, cosmographical texts often borrowed from the diagrammatic tradition of medieval spherical astronomy; for instance, the nested-sphere diagrams representing the heavens and the terrestrial Elements according to Aristotle. Planetary models, however, typically belonged to the tradition of <i>Theorica planetarum</i>; the depiction of world systems in Coronelli's texts therefore reflects the increasing scope of cosmography to include elements of planetary as well as spherical astronomy.</p>