THE GREEN FIELDS OF THE MOON.

New Zealand Tablet, Volume IV, Issue 206, 16 March 1877, Page 9

THE GREEN FIELDS OF THE MOON.

When the moon is at the fall the unassisted eye readily distinguishes on her face certain dark grey spots more or less sharply separated from the brighter portions. Through a telescope these t P a , ap P ear as taoa-d. level spaces, resembling terrestrial seas. Indeed, the earlier observers mistook them for seas, and by that name (Latin mare) they are known to this day. They are not seas, however, but ancient sea beds, now probably, nearly, if not quite destitute of water; vast arid basins like the Sahara, or the great interior Utah basin of America. Examined more closely, these dried-up sea beds — to which Nelson applies the irregular but convenient plural mares, are seen to have a rolling surface like some of the western prairies, or to be traversed by numerous long ridges, resembling the wave-like sandhills which give so marked and peculiar an appearance to the deserts of Western Australia, the levellerportions being dotted with low mounds interspersed with small crater pits. , In many places formations of an apparently alluyial character abound, while the ancient coast lines show distinct traces of water action. Two of these lunar plains— Mare Humoruni and Mare Chrisium—axe walled in completely by lofty mountains, presenting stupendous precipices to the vanished sea. The larger mares are more like ocean beds. They run together as terrestrial oceans do, and sometimes merge into the brighter continental regions without a distinct line of demarcation. In other places they show a rugged coast line, rising into cliffs and peaks, and pierced at times, by valleys and ravines. One of the most conspicuous of these lunar ocean beds, also one of the deepest, is known as the Mare Serenitatis. Its area is nearly 125,000 square miles. Within its dark grey border, from thirty to eighty miles wide, is an extensive inner plain which at times presents a fine, clear, light green tint, with a central streak of pure white, the green area lying lower apparently than the grey exterior. The green tint is difficult to catch, except under favorable conditions, and is much weakened by the effect of numerous small white round spots and grey ridgee. Another of the moon's green plains was discovered by Madler in the Mare Humorum, already mentioned. This is one of the smallest as well as most distinctly bordered of the dark grey plains. Its area is 50,000 square miles. The greater portion of its interior is distinctly tinged a dusky green, sometimes very marked, affording a strong contrast with the pure grey of the borders and hio-b. enclosing ridges. On the west the green area extends nearly to the edge of the mare, but elsewhere, as in the M are Serenitatis, it is separated from the border by a narrow darker grey fringe, except on the north-west, where the grey and green areas mer^e insensibly into each other. — ' Scribner's Monthly.'