MOON AT MIDDAY.

Auckland Star, Volume LX, Issue 181, 2 August 1929, Page 7

MOON AT MIDDAY.

No person has ever seen the full moon at noon in Auckland, and few, if any, have ever seen the sun at midnight, but both phenomena are seen in the Antarctic regions, where Commander Byrd is now exploring. During the height of last summer his party lived in perpetual day, but that did not last long, for £he sun gradually sank, giving them the phases of day and night that we have here, until it disappeared altogether in'the middle of May. It will be remembered that about the middle of June the party were consoling themselves that the sun would soon reach its extreme northern declination, which would take place on June 21, after which they would be living in hopes that it would gradually move southward until they saw it again. That pleasing sight would be on August 2, but the sun would be visible at first for only a few minutes, the days rapidly lengthening

until October or November (according to the latitude in which they were [ camping), when the sun would not set at | all for three or four months. 1 During all this depressing period of ' the Antarctic winter, however, they have ' been extremely lucky, in that the moon has been exceptionally favourably situated. The position must have helped them very considerably, for during each full moon it has been so far south that it has _ illuminated the whole of the Antarctic Circle—and a few hundred miles beyond it also— during the whole 24 hours. During next year the conditions will be just a little better, but hardly enough to make much I difference to the facilities for exploring. The reason for this most fortunate disposition of the moon is that next year the moon reaches what is called its maximum declination. This is in a recurring cycle of 18J years, and at its maximum, which will be in October of next year, it will reach 28§ decrees from the equator. The sun never goes beyond 231 degrees from the equator, the extra five degrees at its maximum next year giving another 350 miles outside the Antarctic Circle the benefit of 24 hours of moonlight each moon. However, this winter it has been swinging about 27 degrees south, as anyone.would see who cared to notice the rising and setting of the full moon during the past few months. It has appeared and disappeared at a point on the horizon considerably to the southward of where the sun rises and sets in the height of summer. This constitutes the good fortune of the explorers, and doubtless accounts for their frequent reference to the moonlight they have enjoyed, although they have never actually stated that the full moon has been shining on them during the whole of the 24 hours each day.

! Probably most people understand the principle on which Arctic exploration is always undertaken during May, June, July and August, when it is facilitated by "what Marie Corelli so graphically describes in the "Land of the Midnight Sun," and these conditions prevail during the opposite months in the Antarctic, but few have troubled to calculate the fortunate conditions that have attended Commander Byrd during what is always a terrible winter. It is true that during the time of new moon, when the moon is not much use, they could not see it at all, but before and after each

full moon they have had the benefit of its light for the whole 24 hours to an extent which will only be exceeded next year by a fraction and will not be as good again for another 19 years.