On This Day - June 3rd 1769
Lieutenant James Cook observes the transit of Venus across the sun, on the trip during which he would chart Australia's eastern coast.
Lieutenant James Cook was not the first to discover Australia, as he was preceded by numerous Portuguese and Dutch explorers. He was, however, the first to sight and map the eastern coastline when he was sent to observe the transit of Venus across the sun from the vantage point of Tahiti. The transit of Venus occurs when the planet Venus passes directly between the Earth and the Sun, and its unlit side can be seen as a small black circle moving across the face of the Sun. Transits of Venus occur in pairs, eight years apart, approximately once every 120 years. Cook's ship, the 'Endeavour', departed England, on 25 August 1768. Cook reached Tahiti in time for his crew and scientists to set up their instrumentation necessary to observe and report on the transit, which occurred on 3 June 1769.
After observing the transit of Venus, Cook went on to search for Terra Australis Incognita, the great continent which some believed to extend round the pole. It was shortly after observing the transit of Venus that Cook came across New Zealand, which had already been discovered by Abel Tasman in 1642. He spent some months there, charting the coastline. Nearly a year later, he set sail east for New Holland, later Australia.