Today is the Autumn Equinox. The word “equinox” comes from Latin aequus, meaning “equal,” and nox, “night.” On the equinox, day and night are roughly equal in length. The equinox is a seasonal signpost in Earth’s orbit around the sun. During the equinox, the Sun crosses what we call the “celestial equator”—an imaginary extension of Earth’s equator line into space. The equinox occurs precisely when the Sun’s center passes through this line. When the Sun crosses the equator from north to south, this marks the autumnal equinox; when it crosses from south to north, this marks the vernal equinox. After the autumnal equinox, days become shorter than nights as the Sun continues to rise later and nightfall arrives earlier. These shorter days bring cooler weather. You can feel the chill in the air. This ends with the December solstice, when days start to grow longer once again.
And, we had the Harvest Moon two days ago. As I mentioned yesterday it was so bright in the morning that it cast shadows across the meadow at Pineridge Natural Area.
- Information on the Equinox was stolen from the Farmers Almanac and EarthSky
