NEB broadening had almost encircled the planet, forming new distinct northern edge at about +20 deg. in latitude, though in the sector between II:50 deg. and 140 deg., north of RS, the belt was seen somewhat narrower, possibly indicating that the broadening had not completed in the sector, yet. The pattern of Jovian belt/zone is controlled by jetstreams, and normal position of NEBn edge corresponds to that of retrograding jetstream at +17 deg. in latitude. Newly formed northern edge lies in the steep gradient of velocity leading to the fastest NTBs prograding jetstream (North Temperate Current-C). It is interesting that the boundary of the belt clearly forms in such a steep gradient. In a typical cycle of NEB activity, the appearance of an array of dark barges and white spots in NEBn follows the broadening of the belt, but no such features were observed, so far.

North of NEB, NTB became still fainter. Though NTB had clearly been seen as a faint gray streak in the first half of the apparition, it completely disappeared even in high resolution images, except for the sector between II:0 deg. and 160 deg., where only weak trace of the streak was seen. It seemed that this was an influence of NEB broadening, because the faded sector generally corresponded with broadened NEB. Anyway, it indicated that the beginning of next North Temperate Current-C became imminent.

SEBn rift of EZs/SEBn disturbance passed again north of RS early June. It was at I:196.1 deg. (Jun. 17, Miyazaki) and indistinct as SEBn shallow bay. Strongly bluish SEBn have been a characteristic of this apparition, and various sizes of white spots emerging in activity of EZs/SEBn disturbance were also seen in this region. Since mid-May, however, at region where SEBn rift passed, the whole belt aspect was transformed to chaotic state, bluish SEBn breaking up into small fragments and irregular tiny white spots. Such aspect was expanding as SEBn rift prograded, and it covered from II:180 deg. to 280 deg. in June. Since bluish SEBn still remained unchanged preceding RS without influence described above, we should keep watch changes in this region.

BA began the passage of RS. Though it initially estimated to reach f. end of RS early July, it already arrived there on Jun. 27. Such acceleration has frequently been observed when LEBS is approaching RS, while it decelerates after passage. Prominent dusky spot appeared immediately preceding BA while passing RS. It seemed that a part of original dark collar surrounding BA was transformed into dark oval. RS was prominent by orangish color with distinct outline as before, having dark core in its center. The f. end was connected to SEBs by narrow streak, but it was unaffected by the passage of BA, so far. RS was at II:95.2 deg. and BA was at II:107.1 deg. (both Jun. 18, Fukui).

(2) Saturn

Saturn will be solar conjunction within a month, and sinks below the horizon shortly after sunset. Nevertheless, it was still traced by an eager observer.

Altitude of Saturn was only 10 deg. when he took the image in which SEB was barely seen. But his enthusiasm is worth a great respect. Next apparition, we will observe Saturn with Cassini spacecraft. We expect that it will make details of activity on Saturn obvious.

(July 8, K. Horikawa)

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