Edmond Halley FRS (1656 - 1742)
At school, Edmond excelled in mathematics and astronomy. Aged 17, he went to Oxford University, and took with him a collection of fine astronomical instruments purchased by his father. Whilst at university, he met John Flamsteed, the Astronomer Royal at the time. Influenced by John's project to compile a catalogue of the northern stars, Edmond decided to do the same for the southern hemisphere. In 1676, he visited the south Atlantic island of Saint Helena, and set up an observatory. Here, he made the first observation of a transit of Mercury, and realised that a similar transit of Venus could be used to measure the size of the Solar System.
Edmond published his star catalogue in 1678. This established him as a reputable astronomer, and he was elected a Fellow of the Royal Society. In 1704, he was appointed a professor at Oxford University, and continued his observational astronomy. He focused his work on comets, and published A Synopsis of the Astronomy of Comets in 1705. Here, he showed that the observations of a comet in 1456, 1531, 1607 and 1682 were so similar, that it must be the same comet returning. Using this model, he predicted the comet would return in 1758.
In 1720, Edmond succeeded his former mentor, John Flamsteed, as the Astronomer Royal. He died in 1742, and so did not see the comet return on Christmas Day in 1758 - the comet which later became known as Halley's Comet.