On what planet was a large rectangular outcrop that is composed mainly of sandstone first observed by an English astronomer born 1618?
Jeremiah Horrocks Jeremiah Horrocks (1618 – 3 January 1641), sometimes given as Jeremiah Horrox (the Latinised version that he used on the Emmanuel College register and in his Latin manuscripts), was an English astronomer. He was the first person to demonstrate that the Moon moved around the Earth in an elliptical orbit; and he was the only person to predict the transit of Venus of 1639, an event which he and his friend William Crabtree were the only two people to observe and record.
International Halley Watch Halley's Comet, named after English astronomer Edmund Halley who first demonstrated its periodicity, returns to the vicinity of the Sun and Earth approximately every 76 years. Since comets are believed to be the most primordial objects in the solar system, their study is of great importance to planetary science. At the time of the 1986 return (technically, "apparition") of the comet, astronomical telescopes and related instrumentation were vastly more sensitive than for any previous apparition. Consequently, the International Halley Watch (IHW) was organized to stimulate, standardize, collect, and archive observations of the comet.