Saturn in 2001 − 2002

2016 November 21

Richard McKim

Saturn’s atmosphere remained quiet, the only activity being small irregularities within or at the N. edge of the S. Equatorial Belt, and in the Equatorial Band. No rotation periods could be derived for these small, transient features. On the other hand, there were obvious intensity changes in the far south: the tiny dark area at the extreme S. pole (SSPC) was more constantly present, and at high resolution was seen to be surrounded by a narrow light zone. The south face of the rings was displayed nearly to its maximum effect during the current presentation. The various occultations of the planet and its satellites by the Moon were further highlights of the apparition.

Introduction

Saturn was at opposition on 2001 Dec 3, when the sub-Earth latitude was -25.9°. During the period of observation this quantity attained -26.4°, a shade less than the maximum figure of -27.0° that would be reached for the presentation of the south face of the rings, during 2002-’03. Solar conjunctions were on 2001 May 25 and 2002 Jun 9, and our data span 2001 Jul 29 (Gray) till 2002 Apr 23 (McKim). The planet’s declination at opposition was +20°: very favourable for north temperate observers. The writer experienced many clear nights, but seeing for visual work was less favourable than during the previous winter’s observing season. This was also the experience of some other observers.

Many high quality images were taken. Among the new contributors we have Grafton’s fine work: his images achieved the highest resolution of all those submitted. Akutsu again contributed infrared images; their appearance is very similar to those of 2000-’01. No groundbased image revealed much in the way of spot activity. No images were taken with the HST, but a superb infrared image by the VLT was published (in false colour) on the front cover of the Journal. The number of visual contributors declined in 2001-’02, but several of these observers obtained long series: Foulkes observed on 39 nights, and Gray on 45. The Cassini spacecraft continued on its long journey: its first results would be received during the following apparition. …(continued)
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