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.
William Henry Finlay William Henry Finlay (born 17 June 1849 in Liverpool; died 7 December 1924 in Cape Town, South Africa) was a South African astronomer. He was First Assistant at the Cape Observatory from 1873 to 1898 under Edward James Stone. He discovered the periodic comet 15P/Finlay. Earlier, he was one of the first to spot the "Great Comet of 1882" (C/1882 R1). The first telegraphic determinations of longitude along the western coast of Africa were made by Finlay and T. F. Pullen.