Sky Matters: Autumn Equinox brings science and mythology together

Our ancestors who built stone circles poured their hearts and souls into their construction 

At the present day we’re in a period where the Moon’s influence on high tides is relatively benign, but in the 2030’s the reverse is true.

We’re all pretty familiar with the idea that the Moon causes tides twice a day. These play a key role not only at the coasts where they are most obvious but also deep within the oceans where they contribute to the movement of huge volumes of water that, amongst other things, help support sea life. 

What we’re probably less familiar with is the longer-term influence of the Moon on our planet. Careful observations show the Moon goes through an 18.6 year cycle, a fact that may have been known for thousands of years.