In this paper we analyze the influence of positivism in Argentina astronomical culture in the nineteenth century. We did the analysis from two dimensions, scientific knowledge development and science teaching. Because Argentina was a very young country at that time, it was of singular importance, not only the development of scientific knowledge itself, but also the training of human resources for the transfer of such knowledge. In this regard, the influence of astronomy, in its role of modernizing discipline related to positivist ideal, was particularly noticeable in the training of teachers of primary schools. Domingo F. Sarmiento represents a turning point for the astronomy development in Argentina; his thought was strongly influenced by the Comtean positivism. Sarmiento believed that Copernican astronomy was one of the critical scientific disciplines to the formation of a "modern" citizen. Astronomy in Argentina was influenced by two epistemological streams: French and German positivism; however the first one was the most important. We shall show the relevant influence of the socio-historical context over the scientific development. We shall also see that science was a fundamental social actor in Argentina history.