Jeremiah Horrocks

Jeremiah Horrocks
Making the first observation of the transit of Venus in 1639
Born	1618 Lower Lodge, Otterspool, Toxteth Park, Liverpool, Lancashire, England
Died	3 January 1641 (aged 22) Toxteth Park, Liverpool, Lancashire, England
Residence	England
Citizenship	English
Nationality	English
Fields	Astronomy Mathematics Mechanics
Alma mater	University of Cambridge
Known for	Transit of Venus Tides Elliptical orbit Lunar orbit

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.

His early death and the chaos of the English Civil War nearly resulted in the loss to science of his treatise on the transit, Venus in sole visa; but for this and his other work he is acknowledged as one of the founding fathers of British astronomy.

Jeremiah Horrocks was born at Lower Lodge Farm in Toxteth Park, a former royal deer park near Liverpool, Lancashire. His father James had moved to Toxteth Park to be apprenticed to Thomas Aspinwall, a watchmaker, and subsequently married his master's daughter Mary. Both families were well educated Puritans; the Horrocks sent their younger sons to the University of Cambridge and the Aspinwalls favoured Oxford. For their unorthodox beliefs the Puritans were excluded from public office, which tended to push them towards other callings; by 1600 the Aspinwalls had become a successful family of watchmakers. Jeremiah was introduced early to astronomy; his boyhood chores included measuring the local noon used to set local clocks, and his Puritan upbringing instilled an enduring suspicion of astrology, witchcraft and magic.

In 1632 Horrocks matriculated at Emmanuel College at the University of Cambridge as a sizar. At Cambridge he associated with the mathematician John Wallis and the platonist John Worthington. At that time he was one of only a few at Cambridge to accept Copernicus's revolutionary heliocentric theory, and he studied the works of Johannes Kepler, Tycho Brahe and others.