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  1. ITV Report

Autumnal equinox today

Astronomical seasons Photo: Met. Office

Between the two solstices we experience the equinoxes which mark the beginning of spring and autumn. At equinox, the plane of Earth's equator passes the exact centre of the sun. This means that the Earth is neither tilted towards or away from the Sun.

When this occurs on 20/21 March in the northern hemisphere it marks the point at which the northern hemisphere begins to tilt towards the Sun and consequently the beginning of the astronomical spring. Similarly on 22/23 September, equinox occurs again this time marking the point at which the northern hemisphere begins to tilt away from the Sun and consequently the beginning of the astronomical autumn.

Another notable attribute of equinox is that the night and the day are of roughly equal length. The word 'equinox' is derived from the Latin aequus (meaning 'equal') and nox (meaning 'night').