Our Astronomical Column

Abstract

July and August Meteors.—Mr. W. F. Denning writes: “The season for meteoric abundance has now opened and a large number of showers are visible, including the early phase of the great Perseid display. The latter appears to be visible during the whole of July and August with a maximum on Aug. 11 or 12. Probably the morning of the latter is the period when most meteors will be visible. The present year seems likely to be favourable for the occurrence of many meteors, for an abundant maximum of 250 per hour for one observer was counted in 1921 on the early morning of Aug. 12. The earth will occupy very nearly the same position in its orbit on the morning of Aug. 12 next, and the shower may be repeated if the density of the part of the stream encountered is about equal to that through which the earth passed eight years ago. This maybe doubted, however, though there are slight evidences of an eight-year period in the character of the display and observations may prove specially interesting. The Capricornids (July 19Aug. 6) with radiant at 304°–11°, and the Aquarids (July 24–31) radiant 338°–11°, usually form two of the principal displays of the July–August period; but there are some hundreds of others exhibiting various degrees of strength, though the majority are very attenuated and are only to be recognised by long and accurate observation.”