Rare Moon Event May Shed Some Light on Stonehenge

Researchers have a rare window to observe Stonehenge's possible connection to the moon during an upcoming phenomenon known as a lunar standstill. As the BBC notes, scholars commonly believe the site had cultural and ritualistic connections to the sun during solstice. But the positions of four of its original small boulders, called Station Stones, align with the moon at its most extreme positions, according to Smithsonian Magazine—when the distance between moonrise and moonset along the horizon are furthest apart. "Researchers have debated for years whether this was deliberate," says the University of Leicester's Clive Ruggles, "and if so, how this was achieved, and what might have been its purpose."

This lunar standstill occurs every 18.6 years, with the current phase starting in the spring of 2024 and lasting through mid-2025. Popular Mechanics notes that its pinnacle occurs in January 2025. It's possible those who constructed Stonehenge during its early stages some 5,000 years ago witnessed at least one lunar standstill, which may have influenced its design. Researchers from Leicester, Oxford, and Bournemouth universities will work with the Royal Astronomical Society and English Heritage (a charity that manages historic buildings, monuments, and places like Stonehenge) on the project. "We'll never be able to prove this, but the greater understanding we can get of these monuments and the moon, the stronger the argument will be," says Bournemouth's Dr. Fabio Silva.

Tapping into the public's passion for the mysterious stone circle, they plan to involve enthusiasts via lectures, a pop-up planetarium, and by livestreaming its southernmost moonrise. Thousands of visitors flock to the site during summer solstice to celebrate the sun's unique alignment with the formation during sunrise. "Unlike the sun, tracking the moon's extremes isn't straightforward, requiring specific timing and weather conditions," says Oxford University's Amanda Chadburn. "We want to understand something of what it was like to experience these extreme moonrises and sets and to witness their visual effects on the stones." (Get ready to set your clocks for moon time.)