Starwatch: Night and day reach identical length after autumnal equinox – Guardian

Welcome to autumn! The northern hemisphere’s autumnal equinox took feature on 22 September. This is the day on which the solar crosses the celestial equator, transferring from the northern celestial hemisphere to the southern.

The celestial equator is the projection of the Earth’s equator up into the sky. So, on the equinox, the solar is sharp without lengthen above Earth’s equator, and this creates nearly equal hours of daylight and darkness all over the globe. This is reflected in the title. The note “equinox” comes from the Latin phrases aequus, meaning equal, and nox, meaning night.

A subtlety is that since the Earth’s atmosphere bends sunlight, a route of identified as refraction, every day we are going to be succesful of search for the solar just a few minutes sooner than it rises and 2 minutes after it sets in the night.

The life like upshot of that is that the length of the day is incessantly elongated by just a few minutes on the expense of the time we employ in darkness. So, on the equinox itself, the day will always be quite longer than the night.

A pair of days later as the nights receive longer, we journey correct equal day and night length. This is identified as the equilux (equal gentle).