I was drafting a summary diagram for use in a presentation I'm giving tonight to the Hampshire Astronomical Society on the Astronomy of Stonehenge.
Building on previous work (see "Is the Altar Stone the founding stone of Stonehenge?" and "Implications of an upright Altar Stone in WA 3639"), I was working on this image:
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| Red lines are the Station Stone rectangle, yellow ones are the solstice axes |
While labelling it up, I suddenly realised that it wasn't complete.
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| What's missing from this picture? |
While both the solstice axes are present, aligned to Winter Solstice Sunrise <-> Summer Solstice Sunset and Summer Solstice Sunrise <-> Winter Solstice Sunset, along with the Station Stone rectangle long sides' alignments for Southernmost Major Moonrise <-> Northernmost Major Moonset, the missing element is the other Major Moonrise/Set axis.
Northernmost Major Moonrise <-> Southernmost Major Moonset axis is not represented at all - it appears as if the designers didn't incorporate this. Except... perhaps they did.
The 81° "twist" of the upright Altar Stone so you can sight along its face towards the WSSR<->SSSS directions has another effect. This is the same 81° "twist" that means it lies along that secondary solstice axis in its now prone position in front of the remains of the tallest trilithon, which also shares the same "twist" (see Tim Daw's "The Twisted Trilithon")
It causes the Altar Stone to face the missing Lunar directions.
This is a consequence of the latitude of Stonehenge, where the Northernmost Major Moonrise occurs roughly 9° further north than Summer Solstice Sunrise, and the angle between Summer and Winter Solstice Sunrises (and Sunsets) is 81°, back when the monument was constructed.
The complete diagram of all the alignments encoded with just five stones - the Station Stones and an upright Altar Stone - is this:
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| The Moon and Sun completely encoded with five carefully positioned stones |
Once again, I'm struck by the elegance and minimalism of this structure.
To paraphrase Picasso, when he first saw the cave paintings in Lascaux, we have learned nothing in 5000 years.
