RT @hist_astro: Transit of Venus for 6 June 1761; calculated by N. Ypey according to Halley’s calculations, Amsterdam @rijksmuseum. http://t.co/es0n0p13I8
RT @hist_astro: Transit of Venus for 6 June 1761; calculated by N. Ypey according to Halley’s calculations, Amsterdam @rijksmuseum. http://t.co/es0n0p13I8