EQUINOX

The astronomical autumn beginning, or autumn equinox, takes place when the centre of the sun, observed from the Earth, crosses the celestial equator in its apparent movement towards the south, a position known as “Libra point”. When autumn begins in the North hemisphere, spring begins in the South one. This will happen in Valencia on 23^rd September, at 05:09 am.

(4ºESO- PDC)

EQUINOX

We know as equinox the time in which day and night have the same duration (from Latin aequinoctium, that means “equal night “), in all the places of the Earth except in the poles. An equinox occurs twice a year, both in the autumn and spring beginning.

Sunrise

Is the moment at which the upper edge of the sun appears above a hypothetical horizon in which it is not taken into account the relief of the true horizon, nor nearby obstacles (houses, trees, …), nor the presence of clouds or fog. On 23^rd September  the sunrise in Valencia will take place at 07:50 am.

 Sunset

Is the time when the top edge of the sun disappears in a hypothetical horizon in which we don’t take into account the relief of the true horizon, nor nearby obstacles (houses, trees, …), nor the presence of clouds or fog. On 23^rd September  the sunset in Valencia will happen at 07:57 pm.

So, on 23^rd  September, just when autumn begins, the day will last 12 h 7 min., practically the same as the night: 11 h 53 m (EQUINOX)

 

INSTITUTO FUENTE DE SAN LUIS

4º ESO- PROGRAMA DE DIVERSIFICACIÓN CURRICULAR 2010-11