September 25, 1999 08:13 UT
Instrument: 10-inch Starfinder

Apparent diameter: 48"
Sys I CM: 59°
Sys II CM: 64°

MY sketch is based on observations at 388X and 247X with my 10-inch Newt. Ingress of Io's shadow transit occurred at 08:01 UT. The black, round mark of Io's shadow is visible upon the South Equatorial Belt south (SEBs) border. The SEB has a rich, red-brown coloration preceding the GRS. This is in stark contrast to the lighter appearance of the SEB following the GRS. Preceding the GRS, the SEBs is much thicker than the SEB north (SEBn). A narrow, white rift separates the two sections. Following the GRS, the SEB has dark brown northern and southern borders sandwiching a wide central region. This central region appears much lighter in coloration. Several small ovals and disturbances are visible, the largest and most distinct positioned along the northwest edge of Red Spot Hollow (RSH).

The ovals and disturbances may explain the lighter appearance of the SEB following the GRS. Also, I now understand the reports of the demise of the SEB following the GRS. The change in appearance of the SEB is quite pronounced when the preceding and following sections are observed side-by-side. It really is quite a remarkable contrast that is not nearly as obvious after the GRS sets. The GRS looks something like a clam sitting in the RSH. It transits the CM at 08:16 UT, consistent with a Sys II longitude of 66 degrees. The GRS features a dark border surrounding a very light interior. The interior coloration is broken only by the orange-hued oval just inside the southern border.

The STB is visible across the STrZ from the GRS. A gray tint blankets the hemisphere from this belt to the south. However, the light toned STZ is visible following the CM. The NEB features three festoons and one column along its southern border. These reach across the EZ and connect to the EB. The NTB appears dark and knotted. The NNTB stands alone, the NTZ to the south and the NNTZ to the north. I stay at the eyepiece to catch the ingress of Io's transit. This occurs at 08:41 UT.

September 27, 1999 September 21, 1999


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