Jeremiah Horrocks

Jeremiah Horrocks (* 1619 in Toxteth Park, Liverpool in Lancashire, † January 3, 1641 ), sometimes written Jeremiah Horrox, was an English astronomer.

Life

Horrocks was born in 1619 in Toxteth Park, near Liverpool in Lancashire. His father was a small farmer. He probably came from a Puritan family and studied from 1632 at the University of Cambridge and left them in 1635 without a degree, to take up a course in Hoole, Lancashire.

At Cambridge, he learned the work of Johannes Kepler, Tycho Brahe, Philip Lansberg and other astronomers know. He examined the lunar orbit with the help of Kepler 's laws, studied the tides and discovered the mutual perturbations of Jupiter and Saturn.

On the basis of Lansberg'schen panels and years of personal observations of Venus Horrocks said a transit of Venus for the end of 1639 ahead. Kepler had predicted the Mercury and Venus transits of 1631, but submitted its bills only to 1636th The transit of Mercury on November 7, 1631 was watched by Pierre Gassendi in Digne, the transit of Venus on December 6, 1631 was not visible from Europe.

Horrocks focused the image of the sun through a telescope onto a piece of cardboard and watched as the event. He calculated the transit for his observation Much Hoole, Lancashire, for about 15 clock on 24 Novemberjul. / December 4 1639greg .. His first view of Venus across the sun succeeded at 15:15 clock.

This first confirmed observation of a transit of Venus allowed the orbital parameters of Venus to determine more precisely. Moreover, he was able to achieve a good estimate of the diameter of Venus. The derived Earth-Sun distance of 95 million kilometers, is in proportion to the present value of 150 million kilometers too low, but it was a substantial improvement over the by a factor of 20 too low a value from antiquity that was used until then.

Since his calculations were not completed until just before the event, he could notify any other astronomers except his friend William Crabtree, so that the transit was observed by two people. Horrocks ' results were not published until 20 years after his death, but distorts competitive reasons partially. He died on January 3, 1641 of a sudden illness and was buried in the cemetery or in the old chapel of Toxteth.

The lunar crater Horrocks is named after him.