Stonehenge was the sight of a rare celestial phenomenon overnight on Friday June 21 — a lunar standstill that coincided with a full moon. Lunar standstills happen only every 18.6 years, when the moon reaches its most extreme northern and southern position, making a wider sweep across the night sky, made even more dramatic by a full moon.
Like the Earth’s tilt on its axis, the moon’s orbit has its own tilt, but it changes slightly over an 18.6-year cycle as the moon goes around the Earth in a plane five degrees off from the Earth’s orbit around the sun. The lunar standstill effect also happens over a year or so, so there are more opportunities to see it this year.
For ancient civilisations, these