Solely two of the station stones are nonetheless there. Credit score: Drone Explorer/Shutterstock.
In the case of its connection to the sky, Stonehenge is best known for its solar alignments. Each midsummer’s night time tens of thousands of individuals gather at Stonehenge to have a good time and witness the rising Solar in alignment with the Heel stone standing outdoors of the circle. Six months later a smaller crowd congregates across the Heel stone to witness the midwinter Solar setting inside the stone circle.
However a speculation has been around for 60 years that a part of Stonehenge additionally aligns with moonrise and moonset at what known as a significant lunar standstill. Though a correlation between the format of sure stones and the key lunar standstill has been recognized about for a number of many years, nobody has systematically noticed and recorded the phenomenon at Stonehenge.
That is what we’re aiming to do in a venture bringing collectively archaeologists, astronomers and photographers from English Heritage, Oxford, Leicester and Bournemouth universities in addition to the Royal Astronomical Society.
There may be now an abundance of archaeological evidence that signifies the solar alignment was a part of the architectural design of Stonehenge. Round 2500 BC, the individuals who put up the large stones and dug an avenue into the chalk appeared to wish to cement the solstice axis into the architecture of Stonehenge.
Archaeological proof from close by Durrington Partitions, the place the place scientists consider the traditional individuals who visited Stonehenge stayed, signifies that of the 2 solstices it was the midwinter one that drew the most important crowd.
However Stonehenge consists of different parts, akin to 56 pits organized in a circle, an earthwork financial institution and ditch, and different smaller options such because the 4 station stones. These are 4 sarsen stones, a type of silicified sandstone frequent in Wiltshire, that have been fastidiously positioned to type an nearly actual rectangle encompassing the stone circle.
Solely two of those stones are nonetheless there, they usually pale compared to their bigger counterparts as they’re just a few toes excessive. So what may their goal be?
Lunar standstill
The rectangle that they type isn’t just any rectangle. The shorter sides are parallel to the principle axis of the stone circle and this can be a clue as to their goal. The longer sides of the rectangle skirt the skin of the stone circle.
It’s these longer sides which are thought to align with the key lunar standstill. For those who marked the place of moonrise (or set) over the course of a month you’ll see that it strikes between two factors on the horizon. These southern and northern limits of moonrise (or set) change on a cycle of 18.6 years between a minimal and a most vary – the so-called minor and main lunar standstills, respectively.
The major lunar standstill is a interval of about one and a half to 2 years when the northernmost and southernmost moonrises (or units) are furthest aside. When this occurs the Moon rises (and units) outdoors the vary of sunrises and units, which can have imbued this celestial phenomenon with that means and significance.
The strongest proof we’ve got for folks marking the key lunar standstill comes from the US southwest. The Great House of Chimney Rock, a multi-level complicated constructed by the ancestral Pueblo folks within the San Juan Nationwide Forest, Colorado, greater than 1,000 years in the past.
It lies on a ridge that ends at a pure formation of dual rock pillars – an space that has cultural significance to greater than 26 native American tribal nations. From the vantage level of the Nice Home, the Solar won’t ever rise within the hole between the pillars.
Nevertheless, throughout a major standstill the Moon does rise between them in awe-inspiring vogue. Excavations unearthed preserved wooden that meant researchers may date to the 12 months episodes of building of the Nice Home.
Of six chopping dates, four correspond to main lunar standstill years between the years AD1018 and AD1093, indicating that the location was renewed, maintained or expanded on consecutive main standstills.
Returning to southern England, archaeologists suppose there’s a connection between the key lunar standstill and the earliest building phase of Stonehenge (3000-2500 BC), earlier than the sarsen stones have been introduced in.
A number of units of cremated human remains from this phase of building have been discovered within the southeastern a part of the monument within the normal course of the southernmost main standstill moonrise, the place three timber posts have been additionally set into the financial institution. It’s potential that there was an early connection between the location of Stonehenge and the Moon, which was later emphasised when the station stone rectangle was constructed.
The foremost lunar standstill speculation, nonetheless, raises extra questions than it solutions. We don’t know if the lunar alignments of the station stones have been symbolic or whether or not folks have been meant to look at the Moon by means of them. Neither do we all know which phases of the Moon could be extra dramatic to witness.
A seek for solutions
In our upcoming work, we shall be making an attempt to reply the questions the key lunar standstill speculation raises. It’s unclear whether or not the Moon would have been robust sufficient to solid shadows and the way they might have interacted with the opposite stones. We may also have to test whether or not the alignments can nonetheless be seen immediately or if they’re blocked by woods, visitors and different options.
The Moon will align with the station stone rectangle twice a month from about February 2024 to November 2025, giving us loads of alternatives to look at this phenomenon in numerous seasons and phases of the Moon.
To carry our analysis to life, English Heritage will livestream the southernmost Moonrise in June 2024, and host a collection of occasions all year long, together with talks, a pop-up planetarium, stargazing and storytelling periods.
Throughout the Atlantic, our companions on the US Forest Service are growing instructional supplies concerning the major lunar standstill at Chimney Rock Nationwide Monument. This collaboration will lead to occasions showcasing and debating the lunar alignments at each Stonehenge and at Chimney Rock.
