THE EARTH’S SISTER PLANET

Sun (Auckland), Volume III, Issue 865, 8 January 1930, Page 6

THE EARTH’S SISTER PLANET

Next to the Sun and the Moon the glorious planet Venus is by far the brightest of all the heavenly bodies, and it is curious we should know so little about her. When Venus is examined through a telescope it is usually found that her planetary disc is of uniform brilliance, with none of the conspicuous dark markings such as we find on Mars and Jupiter. Astronomers are inclined to believe, therefore, that the atmosphere of Venus is very heavy and cloudladen, and that any features belonging to the actual surface of the planet are hidden from our sight by the cloudy envelope. Occasionally, however, there is a rift in the clouds, and some dusky marking will bo seen, lasting possibly for several weeks, though more probably only for several days. In such a case the astronomer watches the marking carefully hour by hour and day by day, to see in which direction it moves, and how fast. -Vs long ago as 1759 this method was used, and it appeared that Venus turned round once on her axis in about the same time as the Earth does. Many years later, however, another watcher declared that the planet turned round only once in the course of making a whole revolution round the Sun, so that one side of her surface was always in sunlight while the other suffered nearly the extreme cold of empty space. The general opinion now is that Venus has a day of 68 hours.