Plancius, Petrus

(1552 - 1622)

Petrus Plancius was a Dutch astronomer, cartographer and clergyman. He was born as Pieter Platevoet in Dranoutre, Flanders. He studied theology in Germany and England. At the age of 24 he became a minister in the Dutch Reformed Church.

Because of fear for religious prosecution by the Inquisition he fled from Brussels to Amsterdam after the city fell in Spanish hands in 1585. There he became interested in navigation and cartography and, being fortunate enough to have access to nautical charts recently brought from Portugal, he was soon recognized as an expert on the shipping routes to India. He strongly believed in the idea of a North East passage until the failure of Willem Barentsz's third voyage in 1597 seemed to preclude the possibility of such a route.

He was one of the founders of the Dutch East India Company for which he drew over a 100 maps.

In 1592 he published his best known world map titled "Nova et exacta Terrarum Tabula geographica et hydrographica". Apart from maps he published journals and navigational guides and developed a new method for determining longitude. He also introduced the Mercator projection for navigational maps.

In 1595, he asked Pieter Keyser, the chief pilot on the Hollandia, to make observations to fill in the blank area around the south celestial pole on European maps of the southern sky. Keyser died in Java the following year, but his catalogue of 135 stars arranged in 12 new constellations (some perhaps acquired from the myths of local peoples), prepared with the help of explorer-colleague Frederick de Houtman, was delivered to Plancius, who inscribed the new constellations on a globe he prepared in 1598. Keyser's constellations are Apus the Bird of Paradise, Chamaeleon, Dorado the Goldfish (or Swordfish), Grus the Crane, Hydrus the Sea Monster, Indus the (American) Indian, Musca the Fly, Pavo the Peacock, Phoenix, Triangulum Australe the Southern Triangle, Tucana the Toucan, and Volans the Flying Fish. These constellations, together with three other new ones added by Plancius himself, Camelopardalis, Columba, and Monoceros, were then incorporated by Johann Bayer in his sky atlas, the Uranometria, in 1603.

Plancius was closely acquainted with Henry Hudson, an explorer of the New World.