Abstract
PROF. PICKERING'S LUNAR OBSERVATIONS.—Prof. W. H. Pickering has for many years been making a careful study ot certain lunar tormations under all angles of illumination, finding striking changes of relative luminosity of adjacent markings in the course of the lunar day, which he ascribes to the presence of snow or hoar-frost, or in some cases to vegetation. There can be only one opinion as to the interest and value of the observations, whether Prof. Pickering's conclusions are accepted or not. His latest study (Popular Astronomy, August and September) is of the region round the crater Conon in the Apennines and the neighbouring formation of Bradley. He asserts that this region contains snowfields, clouds, and tracts covered with vegetation. He distinguishes the clouds from the snowfields as being more yellowish, less brilliant, and more subject to change. One note that he makes about them would seem to throw some doubt on their assumed nature. “No clear evidence of motion due to wind has ever been seen in the lunar clouds, which apparently merely form and dissolve in situ.” The white snow-patches, on the other hand, which appear hazy at sunrise, are stated to show some drift; the “vegetation” regions darken conspicuously as the sun rises higher upon them. The author asserts that volcanic activity is by no means extinct on the moon, the floor of Plato being stated to be an active region emitting many steam-jets.
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Our Astronomical Column. Nature 106, 191 (1920). https://doi.org/10.1038/106191a0
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DOI: https://doi.org/10.1038/106191a0