Abstract
Meteorites. Popular Astronomy for May contains an article on meteorites of which the fall has been observed, by Mr. Willard J. Fisher. He points out that these are more frequently observed by day than by night. They differ from meteors in an important respect. More meteors come from the region of the earth's apex than from the antapex; this is from the same cause that makes us meet more vehicles when walking along a street than those that overtake us. But the speed of meteors from the apex is so great (71 km./sec. for parabolic motion) that they are consumed in the upper air, and cannot fall as meteorites. Hence the latter come by preference from the antapex. The minimum speed at which meteors can enter the atmosphere is given as 11-15 km./sec.; this is the speed that the earth's attraction would produce if the earth and meteor were originally at relative rest. Many hundreds of meteor falls have been recorded; of these, thirty have fallen on roads or buildings; this obviously increases the chance of detection. The earth's antapex rises about noon; this helps to explain the greater number of falls by day. Most of those referred to were of the detonating class, and bright enough to be conspicuous in the sunshine.
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Astronomical Topics. Nature 132, 105 (1933). https://doi.org/10.1038/132105a0
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DOI: https://doi.org/10.1038/132105a0