Recent Developments on Jupiter

Abstract

A GREAT revival of activity in the equatorial and south tropical regions of Jupiter has recently set in, and the developments are so rapid and the phenomena presented so interesting that it seems desirable to direct the attention of telescopic observers to what is in progress. The revival began by the appearance of a dark spot in the latitude of the south edge of the south equatorial belt and in longitude 127° (system II). It was observed in the early morning of Aug. 13 by Mr. B. M. Peek, and it quickly began to show marked activity. The extension in the preceding direction (which has recently become much accelerated) has reached at the time of writing as far as longitude 20°, and the disturbance in this part is composed of a series of bright spots and dark peaks and areas. They are mainly in the latitude normally occupied by the south equatorial belt. On the following side of the origin of disturbance a number of small dark spots, which appear to have been successively ejected, are travelling along the south component of the south equatorial belt, rather like beads on a string, in the direction of increasing longitude at the enormous rate of about 5° per day! This corresponds to a rotation period of about 9^h 59^m, which would seem to be unprecedented so far as our knowledge of the planet goes.