The vernal equinox

Today is the vernal or spring equinox, the astronomical start of spring when the length of day and night are equal. The word equinox, in fact, comes from the Latin meaning equal night. Astronomically, the equinox occurs when the sun crosses the celestial equator, an imaginary line in the sky above the Earth’s equator, which occurred today at precisely 16:15, so this photo, taken on Carr Ridge under a setting sun, was well into spring, unlike this morning when winter was definitely still with us. All cultures have recognised the significance of this event, and most will have developed their own traditions to celebrate the passing of winter and the start of spring. There is a 3,000-year-old clay tablet in the British Museum, from ancient Mesopotamia. The characters are in cuneiform writing, pictographs made of strokes from a sharpened reed, and have been translated as ‘On the 6th day of Nisan the day and night were of equal length’.