Bryan E Penprase has written an unusual summary of the role of Astronomy in shaping civilisations' view of the world, and it has a section (p205) on Celestial Cities from Ancient Civilizations and Their Alignments in The Power of Stars, Springer 2011. Whilst in line with scientific conservatism he presents an interesting range of monuments ancient and more recent which appear to conform to some sense of cosmic orientation, including the Kaaba in Mecca, the central pole of Islam as aligned to Solstice winter sunset and summer sunrise. In his diagramming of this using NASA's World Wind software, he presents Clive Ruggles 2005  finding that these solstitial facings of opposite faces of the stylised cubic building also then leave the southernmost face pointing to Canopus rising on the horizon. He tells us " This same alignment was incorporated into other structures in the Islamic world - early mosques in Iraq facing the featured prayer walls that face the winter solstice, while many mosques in Egypt were built with prayer walls facing the direction of the summer solstice sunrise.", presumably then as alignments of that latitude and no longer at right angles to Canopus, which bright yellow star (the heavy one - El Ponderosa) was considered the pole of the world in its southerly manifestation and a source of understanding for some Sufi mystics.
Unfortunately, the author of the diagram seems to have ignored the fact that the (red line) alignment passes through the two "guard" alignments formed by the 18.6 year cycle of the moons nodes, that is, of the retrograde precession of the lunar orbit around the ecliptic plane (of the sun's path) at an angle of 5 degrees. At the angles shown by the guards, the moon can rise further away from east and set further away from west, and so it is then not the solstice sunrise which lines up with the Kaaba but the northernmost moonrise at lunar maximum. The same is symmetrically true regarding solstice sunset, that in fact it is the southernmost moonset at lunar maximum which is indicated in the diagram. This is illustrated below for the situation much further north, in Brittany around 4000BC.
In megalithic terms (and the Kaaba was based on a preexisting megalithic structure) it is the maximum standstill of the moon (at the latitude of the Kaaba) which is at right angles to the star Canopus, but when? Did Penprase use the diagram of solar and lunar extremes of the founding of Islam or of today or some other date? Did he realise that the guard alignments of the solsticial extremes belong to lunar maximum and mininum standstill? The reference to Ruggles below shows Penprase built the diagram.
1. Ruggles, C L N, Ancient Astronomy: and Encyclopedia of Cosmologies and Myth, Santa Barbara, CA, ABC-CLIO
page 202: "...the base of the Kaaba itself—the cube-shaped stone structure at the center of the Great Mosque in Mecca that forms the sacred center of the Muslim world— had been known as far back as the seventh century to have its longer axis oriented upon the rising of the star Canopus and its minor axis aligned (roughly) in line with midsummer sunrise and midwinter sunset. Historically, the assumed qibla is most evident in the orientation of mosques and in the layouts of some cities. In some cases, historical accounts attest to how the sacred direction was actually determined. Thus, we know that the earliest mosques in Iraq were built with their prayer walls facing midwinter sunset in order to face the northeastern wall of the Kaaba, while Egyptian ones were built with their prayer walls facing midwinter sunrise in an attempt to be parallel with the Kaaba’s northwestern wall. However, in many cases we can only speculate about the methods used to determine the qibla. Since the errors were sometimes considerable, anyone trying to reconstruct the motivation behind mosque orientations in the absence of anything but the orientations themselves would have a hard time fathoming that the intention was always to orient them toward Mecca."
There is some historical information of the Kaaba being associated as early as 300BC: "In her book, Islam: A Short History, Karen Armstrong asserts that the Kaaba was at some point dedicated to Hubal, a Nabatean deity, and contained 360 idols that probably represented the days of the year.", but a right angle to Canopus would not apply to that epoch (using CyberSky) and it is also clear that at that latitude, the solstice is going to be around 64 degrees of azimuth (measured from true North, clockwise). Therefore, why not see if Canopus relates to the moon's maximum standstill around the time of Mohammed? Anthony Aveni has prepared a table of sun, moon and star alignments for 1500BC to 1500AD and I have used his figures for 500AD to text whether this is likely the case, as extracted below.
The azimuth for Canopus (the rudder of Argo Navis) is 148 degrees and 21 minutes which, minus 90 degrees is within half a degree of the northernmost lunar maximum moonrise at 58 degrees and 54 minutes. However, Canopus is a bright star which would suffer atmospheric effects, casting doubt on a 0 degree horizon observation being what was being observed. This means that, within the context of Penrase's diagrammatic observations, the lunar maximum was effectively at right angles to the star Canopus on the horizon at the time of Mohammed's involvement with the Kaaba. If the walls of the "cube" monument were built (in proportions 3:4:5) at that time, then the walls aligning to the lunar maximum and Canopus could then be the Muslim tradition thereafter. This is not too surprising because the Islamic calendar is primarily lunar, as seen in the shifting location of ritual months and days within the solar year. I will be confirming the alignments some time soon, with the help of my brother's QuickAz program.
Significance of the Nodal Periods of 18.6 years (6800 days)
In my own Sacred Number and the Lords of Time and on this website, the lunar nodal period can be seen to have had great importance for the prehistoric astronomers and builders of chambered tombs. It was also noted in Mysteries of the Hopewell by Romain that some Native American funerary structures appear to have been aligned to lunar maximum events. An 18.6 year cycle was time on such a scale that only a few cycles, perhaps just one or two, could occupy an individual's lifetime. Monuments have shown, through metrology, that counting within the nodal period from a lunar maximum standstill could predict the minimum standstill after 3400 days and the maximum again after another 3400 days and 3400 (= 17 x 2 x 100) is an easily factored number, an important consideration in pre-arithmetic times. 3400 was 34 lengths of 100 day units of length. Counting added to alignment allows a cycle of time to turn into an organised calendar including midpoints, quarter times and so on.
To study megalithic structures requires the ability to propose alignments as important intentional features. Star alignments, popular in New World astroarchaeology but not encouraged in the Old World, move with precession of the equinoxes whilst sun and moon move as the axial tilt of the earth also changes with time. It is a matter of solving problems using various tools and information that today must be somewhat technical whilst in prehistory, more could be relied upon as directly observed phenomena and this sums up how humanity has changed, from being phenomenon-based observers to problem-solving using mathematics and computation.
For "anyone trying to reconstruct the motivation behind mosque orientations in the absence of anything but the orientations themselves", it may be more important to see Canopus' connection to the lunar maximum in the 7th Century as having been seen emblematic of the creation of a major new religion on earth.
There is a new topic in the new forum where this can be discussed