On what planet was a large rectangular outcrop that is composed mainly of sandstone first observed by an English astronomer born 1618?
Horrocks Block Horrocks Block ( ) is a large rectangular outcrop that is composed mainly of sandstone, lying on the north side of Venus Glacier, 2 nmi southwest of the Keystone Cliffs, on the east side of Alexander Island, Antarctica. It was mapped by the Directorate of Overseas Surveys from satellite imagery supplied by the U.S. National Aeronautics and Space Administration in cooperation with the U.S. Geological Survey, and was named by the UK Antarctic Place-Names Committee from association with Venus Glacier after Jeremiah Horrocks, the British astronomer who predicted and first observed a transit of Venus, in 1639.
Sydney Observatory Sydney Observatory is located on a hill now known as Observatory Hill in the centre of Sydney. The site evolved from a fort built on 'Windmill Hill' in the early 19th century to an astronomical observatory during the nineteenth century. It is now a working museum where evening visitors can observe the stars and planets through a modern 40 cm Schmidt-Cassegrain telescope and a historic 29 cm refractor telescope built in 1874, the oldest telescope in Australia in regular use.