"Active summer for observers"
Lunar Section Report - News Circular 204 - Sep 1998
Section activity has been high this summer, thanks to a core of lunar observers whose skill in depicting the Moon's surface is second to none. If you want to join with us in our pursuit of the lunar wonders, please get in touch.
My own observations have included several CCD runs (terminator sweeps), drawings of Agrippa (3 May); Wallace (4 May); Messier & Messier A (29 May); Fracastorius / Gutenberg (30 May); Mare Humorum (4 Aug). Now I have moved to an address with a far better lunar and planetary aspect I hope to pursue some lines of lunar study brought to my attention by the terrific work of the section members mentioned below.
With his 150 mm Mak-Cass, Nigel Longshaw (Chadderton, Oldham) made a superb observation of the crater Cassini on 3 May, a sight he says was "made even more spectacular by the visibility of Mons Piton picking up the faint rays of the Sun far beyond the terminator....shadow profiles cast by the Caucasus Mountains to the east completed the picture of stark beauty."
Bob Paterson (Speen, Berkshire), one of the most prolific lunar observers the section has ever had, remains active. He drew an impression of the 2 day old crescent Moon on 28 April - a phase not often scrutinised by lunar observers as the Moon at this phase is always rather near to the horizon and embedded in the afterglow. On 3 May he recorded the appearance of the cluster of seas near the Moon's eastern limb, including Maria Smythii, Spumans, Undarum, Marginis and Crisium. Bob zeroed-in on mare Crisium on 30 April, noting the appearance of the sea as it emerged into the sunshine. That evening he also observed Vendelinus, a walled plain near the southeast limb. On 31 May Bob made an observation of Fracastorius, a flooded plain forming a bay on the shoreline of mare Nectaris. The great walled plain Bailly (300 km diameter) near the Moon's southwest limb, the terminator near Schickard and the disintegrated plain Darwin were all on Bob's observing list on the evening of 7 June. On 1 July he observed the crater Walter on the morning terminator, showing a point of light indicating the top few metres of the summit of its central peak. Also that evening Bob caught the craters Autolycus and Aristillus on the sunrise terminator, the pair looking like two enormous black pits and showing intricate ridges and furrows around their eastern outskirts. On 5 August Bob turned his attention to the sunrise terminator near the Moon's southwest limb and took in a broad sweep of the area, from the peculiar elongated walled plain Schiller to the crater Wilson 250 km to the south.
New section member David Todd (Morecambe, Lancashire) has sent some really well- executed drawings in ink and pencil. Featured here is David's observation of the flooded crater Wargentin, positioned right on the sunrise terminator near the southwest limb of the Moon. His drawing, made between 20:00 and 21:30 UT on 5 July, shows a spine-like wrinkle ridge running down the centre of the feature, just illuminated by the rising sun. Wargentin is a feature that probably started life as most craters do, being gouged out of the lunar crust by an asteroidal impact. In Wargentin's case, the subsequent filling with lava - a process that many impact craters have undergone - simply went on for longer than usual, filling the crater right up to its brim. The lava cooled and then the surface slumped, giving rise to the wrinkle ridges.
Using his 150 mm reflector x150, David made further studies of the crater Gassendi (3 Aug), showing the sharp outlines of the spire-like shadows cast by its western wall and central peaks, and also Petavius (10 Aug), noting some very intricate beading effects of the crater's inner terracing as it caught the rays of the setting sun.
Grahame Wheatley (Long Eaton, Nottingham) has maintained a remarkable rate of observations. Their quality is quite breathtaking. Sabine & Ritter (2 May); Aristoteles / Albategnius (both 3 May); Rupes Recta (4 May); Aristarchus (7 May); Schroter's Valley / Aristarchus (both 9 May); Aristarchus (Intensity Estimates, 15 May); Posidonius / Theophilus chain (both 16 May); Aristarchus (Intensity Estimates) /Mare Orientale (both 17 May); Aristillus / Mons Piton / Brown (all 18 May); Plato / Aristarchus (both 19 May); Cleomedes (29 May); Mons Piton & Montes Alpes with spectacular shadows (2 Jun); western limb (9 Jun); Langrenus (12 Jun); Aristarchus (Intensity Estimates) / Cassini (both 16 Jun); Mons Piton (17 Jun); Copernicus (3 Jul); wrinkle ridges, Oceanus Procellarum / Montes Jura (both 4 Jul); Bailly (7 Jul); Langrenus (11 Jul); Rimae Janssen (13 Jul); Theophilus (14 Jul); Montes Harbinger (3 Aug); north of Schroter's Valley (4 Aug); southeast Mare Crisium x2 / Petavius (all 10 Aug); Rupes Cauchy / Fracastorius (both 12 Aug); Lamont & Arago (13 Aug); Clavius / Aristarchus (both 16 Aug). Most were made using a 125 mm refractor, but the latter four studies were made with Grahame's new 240 mm f9.8 reflector - rather an enviable lunar and planetary instrument.
Grahame's observation of the Theophilus chain (Theophilus, Cyrillus and Catharina) on 16 May is a tour de force of lunar observational and drawing skill, a task that few of even the most ardent lunar observers would dare to take on. In an hour and a half Grahame observed what he calls "a wonderful sight at sunset and long awaited. A staggering amount of detail became visible as the drawing progressed....it was good to see even though I could not draw it all - better than a photograph."
The joint Lunar and Planetary Section booklet "Moon and Planets - A Grand Tour" features observations of the Moon and planets, lunar and planetary articles by SPA members, plus useful information for any solar system observer, forthcoming lunar and planetary events, Moon maps and planetary observing blanks. Grand Tour costs (inclusive of P&P) just 15 first class UK postage stamps. To order your copy, send your name, address and postage stamps to Peter Grego.
