Uncovering Stonehenge's Lunar Connection Through a Rare Celestial Event

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For those who have gathered over centuries at Stonehenge, the impressive prehistoric monument that has stood on Salisbury Plain in southwest England for about 4,500 years, it was probably evident how the sun may have influenced its layout.

The central axis of the stone circle aligns with the sunrise at midsummer and sunset at midwinter. The stones frame the rising and setting sun during the longest and shortest days.

Do Stonehenge and other megalithic monuments worldwide also align with the moon?

In the 1960s, the belief that Stonehenge had a connection to the moon started to become more popular. However, according to Clive Ruggles, a retired professor of archaeoastronomy at the University of Leicester, this idea had not been thoroughly studied.

This summer, archaeologists are taking advantage of a rare lunar event that occurs every 18.6 years to help them uncover the reasons behind the construction of Stonehenge.

The moon, like the sun, rises in the east and sets in the west. However, the moonrise and moonset shift from north to south and back again within a month. This movement continues to change over a span of approximately 18 and a half years. During the lunar standstill, the northernmost and southernmost moonrise and moonset are at their greatest distance from each other.

According to Fabio Silva, a senior lecturer in archaeological modeling at Bournemouth University, the moon's rising position changes daily. By tracking this over a month, you would observe that there are northern and southern limits where the moon never rises or sets.

Silva explains that over a 19-year period, these limits go through a cycle of expansion and contraction, resembling an accordion. They reach a maximum limit known as the major lunar standstill before gradually contracting back to a minimum limit called the minor lunar standstill.

This significant lunar event, known as the major lunar standstill, is set to occur in January 2025. Throughout the period leading up to mid-2025, the moon may seem particularly low and high in the night sky to those who casually observe it.

Stonehenge's station stones are thought by some to be aligned with the lunar standstill.

Stonehenge's station stones are thought by some to be aligned with the lunar standstill.

English Heritage

"If you happen to be in one of those 19 years, you may notice that the moon rises or sets much further north or south than usual at certain times. In the years in between, you won't see it in those positions," explained Ruggles.

Although it may seem like the moon is stationary during this time, it is actually not the case, according to him.

Ruggles mentioned that these limits are fixed, with the moment set to occur in January next year. However, for approximately a year before and after that time, if you are lucky enough to witness the moon rise at the right moment, you will notice the moon rising unusually low in the sky.

Stonehenge consists of two different types of stones: the larger sarsen stones and the smaller bluestones that create two concentric circles. According to Ruggles, the station stones at Stonehenge, which form a rectangle around the circle, somewhat line up with the moon's extreme positions during the lunar standstill.

How this lunar alignment was achieved, whether it was by design and its potential purpose are topics of debate that the team wants to investigate.

Stonehenge was built around 4,500 years ago.

Stonehenge was built around 4,500 years ago.

Andre Pattenden/English Heritage

Exploring Stonehenge's connections to the sky

Archaeologists have always thought that Stonehenge was intentionally built with solar alignments, even though there are no written records explaining its purpose. Many other sites around the world also show similar alignments, so it's likely that ancient builders understood the sun's yearly cycle and its importance for the changing seasons.

It is challenging to determine if Stonehenge is actually linked to the lunar standstill. According to Ruggles, "I don't think we can say definitively, but for me, there are some bits of evidence that made me think that it was deliberate."

Archaeologists have discovered cremated human remains grouped together in the southeast, close to where the southernmost moonrise occurs. According to Ruggles, this finding suggests that ancient people may have considered this direction of the moon to be sacred.

Since April, Ruggles and Silva, along with colleagues from Bournemouth University, the University of Oxford and English Heritage, have been studying the moonrise and moonset when the moon aligns with the station stones. According to Silva, the moon is expected to align with the station stone rectangle twice a month from February 2024 to November 2025.

Silva mentioned in an April news release that this alignment will occur at various times of the day and night throughout the year, with the moon in different phases each month.

The team at Stonehenge is interested in studying the patterns of light and shadow created by the moon. They are curious to know if these patterns had any significance to the ancient people who constructed and utilized the monument.

Researchers are investigating lunar alignments at Chimney Rock, Colorado, shown here at full moonrise on December 26, 2023.

Researchers are investigating lunar alignments at Chimney Rock, Colorado, shown here at full moonrise on December 26, 2023.

Amanda Bosh/Stephen Levine

Other monuments with possible lunar link

Stonehenge isn’t the only megalithic monument potentially linked to the lunar standstill.

In the United States, Erica Ellingson, emeritus professor of astrophysics at the University of Colorado Boulder, is currently studying lunar alignments at Chimney Rock. This rocky ridge sits about 1,000 feet above a valley floor in Colorado and is known for its two large pillar-like rocks that frame the horizon.

Between the years 900 and 1150, ancestors of the Pueblo people constructed multi-storied buildings and ritual spaces on this challenging-to-reach elevated location. Ellingson mentioned that the site offers a breathtaking view and continues to hold significance for the 26 Native American groups with traditional or cultural connections to the area.

The view of the sky between the twin pinnacles hints at an astronomical connection, though the gap is too far north for the Sun to shine through. However, the Moon can be observed rising there during its most extreme northern position, particularly during the major lunar standstill season, as mentioned in an email.

Additional proof of moon observation is found in the tree-ring dating of wooden beams in the nearby ancient buildings. This dating suggests that the construction of these buildings is linked to the dates of lunar standstills nearly 1,000 years ago.

The Calanais Standing Stones, located on the Isle of Lewis in Scotland and predating Stonehenge, could possibly be connected to the lunar standstill, according to Ruggles.

Bradley Schaefer, a retired professor from Louisiana State University's physics and astronomy department, expressed doubts about the idea that ancient civilizations were aware of the lunar standstill and intentionally aligned monuments with it. He suggested that it was more likely just a coincidence.

The gold earring found by the scientists, photographed against a dark background, in front of the jar it was found in.

The gold earring found by the scientists, photographed against a dark background, in front of the jar it was found in.

Marco Ansaloni

Related article

Archaeologists believe that a gold earring discovered in the charred remains of an Iron Age village could provide valuable insights into the past. According to experts, ancient sites often have numerous potential sightlines, with some aligning closely with the eight standstill directions.

It can be challenging for someone who casually observes the moon to notice the lunar standstill, as it is best seen through detailed data on moonrise and moonset. The slight shift in the moon's position and the scarcity of historical records on the lunar standstill make it hard to interpret. However, many believe the connection is plausible as ancient civilizations were known to closely study the sky.

“A moon-watcher would have seen the moon start to rise or set outside of these limits, moving farther and farther out of bounds as the major lunar standstill approached,” she said.

Editor's P/S:

The article delves into the intriguing possibility that Stonehenge and other megalithic monuments worldwide may have been aligned with not only the sun but also the moon. The upcoming major lunar standstill in January 2025 provides a unique opportunity for archaeologists to explore this connection.

The article highlights the potential significance of the lunar standstill, which occurs every 18.6 years and marks the extreme northern and southern positions of the moon's rising and setting. Archaeologists believe that the station stones at Stonehenge may have been deliberately aligned with these lunar positions, suggesting that ancient cultures had a sophisticated understanding of lunar cycles.