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The area is now visible from Great Britain in the early evening, and has grown into a significant Regional event. Being late in the season it should not reach encircling status, as no storm occurring after Ls 311 has done so.
I do not think it is appropriate that contributors to this Forum should use anything other than their real name!
I have to write, as a chemist, that amounts of phosphine in the atmosphere of Venus, however small, must be regarded as dubious. In the presence of tiny amounts of oxygen, the gas is spontaneously flammable, forming phosphorus pentoxide as a white smoke, and water vapour. We know that photolysis of oxygen-containing compounds by short-wave UV radiation can produce oxygen radicals in the atmosphere of Venus, so there is certainly going to be a short lifetime for any phosphine. By the way, I often demonstrated its flammability to my A level classes, though I don’t recommend it as a home experiment. You take a tiny piece of white phosphorus, which of course can no longer be bought, and cover it with a few cc of very concentrated NaOH solution, and heat gently it in the fume cupboard. Attach a delivery tube and after a few moments the apparatus will emit beautiful white smoke rings from the end, as each bubble of phosphine combines with the air. No need to add that caustic soda is dangerous, and white phosphorus even more so!
Dawes was a superb observer, for sure. The original drawings for 1864-65 that were used to prepare the engravings for that RAS publication are held in the Mars Section archives. The engravings are faithful reproductions. If you look at the bottom right drawing on the plate there do appear to be four forks, but the one nearest the limb is actually Margaritifer Sinus. In high resolution maps (such as Ebisawa’s, uploaded to the Section website) there is the usual partly resolved broad fork, with lighter shading between, and then a third ‘prong’ on the following or W. side, the latter (which Ebisawa called Brangaena) very thin leading to a very small dark spot at the north end. This can be seen in good current images of the region and I have seen it visually this year. It is of course harder to discover something than for a later observer to confirm it! In 1941 the Pic du Midi observers resolved the westernmost prong of the Meridiani Sinus into two closely spaced prongs, also shown on the Ebisawa map, though it is not a constant feature. So that would make four prongs. Historically there were always large differences in the drawings of this region, with some observers resolving two well-defined forks and others seeing the Sinus Sabaeus-Meridiani region like a sort of meat cleaver.
Although Dawes saw the planet briefly at the next opposition, these views of 1864-65 were his last ones. His excellent series from 1852 was reproduced in a small engraving by Proctor, and used in his well-known map, but they have never been reproduced from the originals.
It is odd that Dawes himself never tried to chart the planet.
Die-hard chocaholics might like to visit the Museum of Chocolate in Prague. It has no telescopes, chocolate ones or otherwise, but it does have many impressive wall paintings done in chocolate. (Liquid chocolate is not very different to thick oil paint, though more unforgiving to the artist as it cools.) When visiting, though probably not during a global pandemic, you are served some melted chocolate, and then you can produce your own chocolate painting on the spot (or drink it). When I went with my family, several years ago, I painted a chocolate portrait. There is scope (pun intended) for an artist to paint something astronomical in chocolate……
I have written about these at the Mars Section 2020 blog page and am about to post an update which includes some further comments on the images by David and others. These projections are always interesting to see, and I think that with the martian atmosphere having been rather free from the effects of major dust storms for several months now that there has also been the very unusual chance to observe shadows of high clouds very close to the terminator: the projections themselves are not so rare, but observations of their shadows are. Because there is always some residual dustiness in the martian air, any details of the terminator must inevitably faded by absorption and scattering of light under oblique illumination.
Lockyer was a very good artist and observer, and his drawings of 1862 are the best available, though there are some other good drawings in the literature. The map given by David is also included in the famous book by Flammarion, and it relied quite a lot on the drawings of W.R.Dawes, whose originals I published in the Journal many years ago. I have seen the hand-drawn original coloured version of the Phillips map, but I do not have the copyright permission to post an image of it here. Comparison shows that once again the engraver did not really do the original map justice. Had Schiaparelli found a more sympathetic engraver who could have rendered the famous 1877 drawings in a closer manner to the originals I am sure that the debate about the martian canals would have evolved differently.
As a matter of fact this idea is not new. In the late 1970s (or perhaps very early eighties) C.Boyer, the French astronomer who discovered the 4 Day rotation of the atmosphere of Venus, published a paper in l’Astronomie mentioning that certain changes in velocity of markings during the course of the Venusian day could be due to the greater activity of life forms in the clouds.
Of course at cloud top level temperature and pressure are quite modest and carbon dioxide still plentiful…… Camille Flammarion would have been keen on this idea, being a great promoter of the concept of Universal life, originally stated by Fontenelle.
This is a good initiative, and I hope it will succeed. There are already (as of today) 64 people who are contributing images and drawings for the current opposition to the Mars Section, and several other BAA members have posted images on their personal pages without contributing them to the Section (I hope they will!), so there must be plenty of people around the world who could make this into a very successful event. I have been writing a regular illustrated blog at the Section website since January…….and I hope to keep it going until the end of the apparition. The 2018 blog is still at the website for anyone who is interested.
There has been further activity upon Mars. There was some local activity in Hellas, which now seems to be finished, a very brief episode of local dust activity in the Argyre basin, and a few days ago (possibly ongoing) there was some dust along Valles Marineris. Of course, the planet is still far from opposition and the disk tiny, but we need more well equipped observers to check all longitudes to provide a good level of coverage. The 2018 opposition showed that we must expect the unexpected….The Section’s 2020 blog has just been updated today. Good observing!
The CD edition was prepared by Sheridan Williams and myself, and it covers the first 100 years of the Memoirs, which is one reason why the last few volumes were not included. Another reason is that we still have a large number of printed copies of the last few volumes for sale, so if anyone wishes to have them they can buy the paper copies. If there is another CD edition in a future year we might include the later volumes. As has been mentioned above, the Halley Memoir is available (as an exception) online, but the others are not. I am glad that the CD has sold well. For those interested in the old publications, we do have copies of many Memoirs for sale beyond those listed on the BAA website and do please ask me for details using my contact details in the Journal, if you wish.
Yes, there is still a lot of interest in her, and as Archivist I have been asked to supply her portrait on several occasions. We still have the telescope she used for her sunspot observations: well, the tube at least. The BAA library archive does not have any copy of the 1880s books she wrote under a pseudonym, about her eclipse expeditions, but I gather they can now be ordered as reprint editions. We must also remember that she was Director of the Solar Section of the Liverpool AS before 1890. It would be interesting to hear a little more about her activities in the LAS.
Yes, in the way all researchers with television companies seem to operate, they contacted me a few days before filming to ask whether I could supply information about Miss Brown. Of course I did so but could have helped more with a little notice.
Yes, 1922 it is! It will soon be a Centenary for the Handbook.
And for those who collect back numbers we can sell you almost any year back to 1936, when the cover was changed to stiff card instead of the original thin pink paper. The earlier ones are much less common, and it is a pity the Council tried to save pennies in 1922. Mind you the Journal also had a very thin paper cover until 1936 when it too was redesigned.
The Handbook for many years was without a pictorial cover. Some opposition was encountered in adding one some two decades ago, but so long as the pink colour of the cover was retained, the Council seemed happy to support the change.
I was intrigued to see this photo, and to hear of observations by David, whom I have not seen in many years.
David’s comments reminded me of the advice to astrophotographers about capturing star colours on film (or electronically I suppose). Defocusing the camera lens reduces the intensity of the star image and allows the colour to be recorded much more clearly. I think there is an image by David Malin showing this effect, where star images were progressively defocused.
As I recall, David has an excellent location. The former perihelic opposition could have been 1971, 1973 or 1975.
The red colour of Mars to the naked eye was modified by the recent large dust storm, with several observers seeing a more yellowish tone. Now it seems more nearly normal. I would encourage this sort of observation.
The Moment magazine now carries a short interview with me about George. The magazine now gives details of the lecture, which I have added below:
Peterborough’s Astronomer
Tues 23 Oct, 7.30-9pm
Peterborough Cathedral Visitor Centre
Tickets: £5
To book: 01733 355315, http://www.peterborough-cathedral.org.uk/events
George Alcock was a prolific Peterborough-based amateur astronomer, commemorated by a memorial tablet in Peterborough Cathedral. Join Dr Richard McKim – a member of the British Astronomical Association – for an illustrated talk about Alcock’s life and work.
I should like to add that we also have spare copies of the hardbound Index to the second fifty years of the BAA Journal to give away to members who would like them (Volumes 51-100, 1940-1990), as there is a large stock.
Several members have taken up the offer of free publications, so if anyone else would like any they should get in touch with me sooner rather than later before stocks are exhausted.
I saw some references above to the very interesting publications that Maurice edited years ago, when microcomputers first appeared on the astronomical scene. If anyone has copies of these bulletins that they no longer want, we do not have anything like a complete set of them in the archives at the BAA Office. For some reason Section circulars were not always retained in the former Library, but what might have seemed common and even ephemeral at the time have become rare with the passage of time! And the same thing applies to the Artificial Satellite prediction sheets that were issued every fortnight or every week……
It is rather surprising that the BAA did not produce a Memoir about this notable event, having produced special publications for the novae of 1901 and 1912. But there was a report in the Journal, and much discussion about who the discoverer was. This report in the Journal however reported only the early observations, and of course the nova was followed by many observers into 1919 and much beyond. When I wrote up my biography of Eliot Merlin for the Journal I included many of his nova observations, made under the clear skies of Volo, Greece. He had a long series of records of the 1918 one, with spectroscopic and colour records, and a copy of all his original data was given to the VSS.
In passing, I wanted to add that I used to know a relative of T.H.Hony of Fowey, the late Mr Viv Hony, for many years a teaching colleague at Oundle School. He taught mathematics and was also a keen amateur astronomer.
I hope all observers will have a look. In two papers just accepted for the Journal, I have analysed all 14 elongations of Venus for 2007 till the start of 2018, and the second paper deals with the nocturnal hemisphere. I am copying the Abstract here in case it is of interest to members: Here we discuss the nocturnal hemisphere, with details of infrared thermal emission (IRTE) imaging and the Ashen Light (AL). Images of the IRTE revealed up to nine topographic features upon the surface of the planet and enabled the slow rotation rate of the surface to be measured for the first time from amateur images. D.Gasparri was able to record subtle, large-scale IR-absorbing low-altitude clouds, which were more prominent in 2009 than in 2017. The 2017 inferior conjunction saw remarkable high resolution reached by P. Miles and A. Wesley: the small bright spots they were able to resolve upon the planet’s surface might provide evidence for active volcanism. The AL was recorded in a small number of visual observations, though only a few sightings were confirmed by a second observer. However, on 2009 Mar 12 the AL was imaged in the visible waveband by Gasparri and independently observed at the eyepiece – at the same hour – by G. Adamoli. The few positive AL sightings seem to be linked to solar Coronal Mass Ejection events. We review possible mechanisms to account for the AL.
So there will be quite a lot in print in due course. Meanwhile I remind all serious observers that the Ashen Light can only be searched for against a properly dark sky background, and that the declination at inferior conjunctions determines whether the northern or southern hemisphere will be suitable from which to make observations.
Richard McKim, Director
