(both: hŏr´eks) , 1618?-1641, English astronomer. He made the first observation of the transit of Venus. His Venus in sole visa, which narrates this experience, was printed by Hevelius in 1662. The transit occurred on Nov. 24, 1639; Horrocks watched the small shadow of the planet move part way across the disk of light on a white screen, where the sun's image was focused through a telescope. Other fragments of his works besides the Venus were edited by John Wallis (1672). Horrocks estimated more correctly than anyone else had yet done the distance of the sun from the earth.
