Volume 114, No.4: 2004 August
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The Journal of the British Astronomical Association
Contents
Following a seven-year journey through the solar system, the NASA spacecraft Cassini, carrying the ESA Titan probe Huygens, arrived at Saturn on 2004 July 1. With a flawlessly executed manoeuvre and 95-minute engine burn the spacecraft passed twice through Saturn's rings and took up orbit around the planet, ready for its four-year mission to study the Saturnian system. The cover shows Saturn's atmosphere and rings, imaged on 2004 May 15 from a distance of 24.7 million km; and three closeup images recorded during the ring plane crossing. Clockwise from right: density waves and unexpected detail in the A ring, exquisitely delicate patterning in the F ring, and the Cassini Division, seen from the unlit side of the rings. NASA/JPL/Space Science Institute. [Hazel McGee and Nick James represented the BAA at JPL during this historic event, and will report further in future issues of the Journal.].
Selected images of the Venus transit from BAA members, and details of how you can contribute to the BAA record of the event.
Completing the wish list (Tom Boles) / Prepare for the Perseids! (Neil Bone) / Aurora Section (R. J. Livesey) / Nearest and farthest (Andrew Hollis) / Visual observations of Mercury in 2003: First interim report (Mario Frassati) / Solar Section (Geoff Elston) / 'Encouraging progress' for Armagh Observatory's dark sky campaign (John McFarland, Mark E. Bailey & Apostolos A. Christou)
The ultimate location for amateur astronomy?... Damian Peach
Jupiter in 2000/2001. Part I: Visible wavelengths - Jupiter during the Cassini encounter ... John Rogers, Hans-Joerg Mettig, Damian Peach & Michael Foulkes
Observing eclipsing variables: a beginner's guide ... Tony Markham
Visual observation of meteors ... Neil Bone
Main articles
Most of the major spots had persisted from the previous apparition, especially anticyclonic ovals, and their drifts, circulations, and appearances were largely unchanged. These included not only the Great Red Spot and a brown ring in the S. Tropical domain, but also anticyclonic white ovals in almost every other domain. Some of these, in latitudes ranging from the South Polar region to the N.N. Temperate region, apparently persisted between apparitions in spite of showing large and sudden changes in their drift rates.
Outbreaks of dark spots were continuing in the SEBs, NTBs, and NNTBs jetstreams. In addition, we detected several spots moving in the SSTBn jetstream, which has rarely been detected from Earth, and one each in the NTBn, NNTBn, and N5TBs jetstreams, which have never previously been detected from Earth.
The highlight of the apparition was the Cassini spacecraft flyby. Cassini images revealed details of all the spots and circulations that we recorded; examples are presented in an Appendix. Observations at non-visible wavelengths, from amateur and professional observers and from Cassini, will be presented in Parts II and III of this report. (22pp)
Visual meteor observing is, rightly, seen as an easy field in which to partake, but there are some important points to remember - as I shall outline here - which will make the resulting records suitable for more detailed analysis that can reveal interesting features of how the regular annual showers behave, and sometimes change, over various timescales. (4pp)
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