Halley’s comet; a benevolent visitor to Earth

In late 1985 and early 1986 a comet was visible to the Earth that has been observed for over 2000 years. One of the most famous of celestial visitors, Comet Halley appeared last in 1910 and will not be seen again until the year 2061. the comet has been the focus of intense studies during the International Halley Watch. A fleet of Soviet, Japanese and European spacecraft was launched specifically for a direct encounter with the comet in March of this year; numerous ground-based astronomical observations are being made, while other investigations are being made from Earth-, Venus- and interplanetary-orbits. In short, Comet Halley will have been one of the most significant scientific occasions of the decade.

In 1705 Edmund Halley, Professor of Geometry at Oxford University, collected and organized a mass of information on comets observed in 1531, 1607, and 1682, a task for which he had an uncommon genius. He was able to show that the comets had very similar orbits, and correctly drew the conclusion that they were the same object and more importantly that comets could therefore be periodic. He predicted that this comet would again be visible from the Earth in 1759. Since then it has been known as Halley's comet and it has played a significant role in the development of astronomy.