TRANSIT OF MERCURY ACROSS SUN

Dominion, Volume 34, Issue 42, 13 November 1940, Page 6

TRANSIT OF MERCURY ACROSS SUN

Observed Yesterday From Wellington SEEN BY CAPTAIN COOK ON FIRST VOYAGE Observers watching through telescopes fitted with dark glass yesterday morning and early afternoon saw a small dark spot move slowly across the face of the sun. They were witnessing the transit of the planet Mercury, the first since 1927. In Wellington the transit was studied by Carter Observatory astronomers, and the director, Air. M. Geddes, said it went according to programme. Tbe transit lasted from about a quarter to 9 till a quarter to 2. Conditions were satisfactory, tbe atmosphere fairly clear and definition fair. About 40 photographs were taken. The planet could be discerned with a small telescope.

The transit of Mercury occurs fairly frequently. It took place, for instance, iu 1907, 1914, 1924 and 1927, and will do so again in 1953, 1957 and 1960. It invariably takes place in November or May, generally November, tbe relative positions of the three heavenly bodies concerned being suitable only at those periods of the year. First to observe a transit of Mercury from New Zealand was Captain Cook, who named Mercury Bay, Bay of Plenty, from the fact that he made this observation from, there, in 1769, on bis first voyage of discovery. On November 4 he anchored a little within the south, entrance of the bay. In his journal he wrote: “My reasons for putting in here were tbe hopes of discovering a good harbour and the desire 1 had of being in some convenient place to observe tbe transit of Mercury, which happens on the 9th instant, and will be wholly visible here if the day is clear. If we be so fortunate as to obtain this observation, the longitude of this place and country will thereby be very accurately determined.”

During the ten days he lay at anchor there, Cook not only observed the transit, but explored the neighbourhood and traded with tbe natives, whom he found an aggressive and dillicult crowd. He records with disapproval that Lieutenant Gore killed a man who was trying to get away with some article offered in the course of trade. The Maoris had previously flung spears into the ship, and. threatened to attack her, and muskets and “the great gun” had to be fired to keep them in order.