On the evening of April 3 the Moon will drift into the Earth's shadow and become totally eclipsed. Lucky observers will be treated to one of astronomy's most spectacular sights. The eclipse begins at 21h 16m UT and ends at 03h 04m, though the first and last hours of this period are occupied by the penumbral shadow, which is not particularly prominent or breathtaking to behold. Observers should expect to see things really start to happen when the "proper" dark umbral shadow bites an increasingly large chunk out of the left side of the Moon from 22h 21m onwards.The Moon will be totally immersed in shadow from 23h 26m until 00h 53m, a super treat lasting nearly an hour and a half - there won't be a longer lunar totality seen from Britain until 2011 June 15, so make the most of it. In all probability it the Moon will remain easily visible to the naked eye, a globe tinted with red tones. It is impossible to predict with certainty how intense these colours will be. One thing is certain - no two total lunar eclipses are the same.
Do prepare yourself well in advance. On paper the eclipse appears to be a long drawn-out event, but in reality the time flies by at quite a rate, especially if you have a planned schedule of observations to make.Simple line drawings on 50mm diameter blanks may be done at 15 minute intervals (remember to note the time each drawing was made). Short notes should be made on the sharpness and definition of the umbra's edge, and the colours and intensities within it.
You might like to estimate the brightness of the totally eclipsed Moon by comparing it with a star of known magnitude. Try looking at the Moon through the wrong end of your binoculars and directly compare it with the surrounding stars of Virgo, nearby Spica for example (magnitude 1.2).Binoculars will give you the best overall view the eclipse. The colours can be striking, and the sight of the Moon surrounded by the dark starry field of Virgo will give a distinct three-dimensional impression.The passage of the edge of the umbra over certain prominent lunar features may be timed to the nearest minute. The recommended features (most of them bright spots) include the craters Aristarchus, Kepler, Copernicus, Tycho, Plato, Manilius and Proclus. A contact timing should be made on the feature's immersion into, and emergence from the shadow.Good luck and clear skies. Don't forget to send me the results of your eclipse watch. I hope to make a full report for the next News Circular and the section's journal "Luna".
John Coates (Burnley) using his 300mm reflector to good effect, made observational drawings of Rima Birt and dome (1993 Dec 22); Mount Piton (Sep 2); Mount Piton on the dark-side of the Moon, with its upper slopes catching the light of the rising sun / Autolycus, noting a darkish shadow band on inner western wall / two unnamed hills southeast of Autolycus (all Oct 1); Promontory Laplace (Oct 4); Rumker plateau (Oct 6) noting how odd (in a geological sense) this feature appeared; Hortensius hill complex (Nov 2). John's drawing of Jansky (Oct 8) is featured. This crater, which is situated on the 90° E line is not often seen so favourably. John's observation was made just three hours after the penumbral lunar eclipse, the end stages of which were theoretically visible from sourthern Britain. Because it was so unfavourable I am not surprised that no reports of this event were sent in.
John Coates drew Jansky as seen with his 300 mm reflector on October 8
Bob Paterson (Speen, Newbury), observing with his 150mm reflector, has made the following impressive series of observations since the summer:- general lunar observing sessions, notes made (Jul 8 & 9), pointing out the striking convex floor of Mersenius; Walter (Aug 3); general lunar observing, notes made (Aug 8 & 19); Sporer through Ptolemaeus, Alphonsus, Alpetragius and Arzachel (Sep 3); noted smooth putty-like appearance of Mare Crisium (Sep 11); Gutenberg region, depicting a faint ring-like feature to north, whose low walls were composed of wrinkle ridges in Mare Fecunditatis (Sep 28); Cuvier, Clairaut, Licetus and Heraclitus area (Oct 1); Albategnius & Hipparchus, noting broad arrow-shaped ridges running into Sinus Medii (Oct 1); Flammarion area to the terminator (Oct 2); Eratosthenes and Sinus Aestuum, noting a peculiar swirling effect of low ridges across the marial plain (Oct 2); general Full Moon lunar observing session, aided by a dictaphone (good idea that, Bob!) taking in many features including Grimaldi, a curious footprint-like feature west of Gassendi, and Maria Humboldtianum, Marginis, Smythii and Australe (Oct 7); Janssen and environs (Nov 26); Eudoxus and Aristoteles / Walter area (both Nov 29). Something of a rarity, Bob reported nothing of a lunar nature for December.
The section is running a bit low on regular observers. If you have lapsed, I would like to hear from you again. If you're a newcomer to astronomy, try your hand at some lunar observation - by far the most visually rewarding branch of astronomy. Do write and find out more about the SPA Lunar Section.
