(MENAFN - The Peninsula) The Peninsula
DOHA: The Qatar Calendar House has announced that the Sun will be completely perpendicular to the equator tomorrow at 4.15 am Doha time.
Dr Bashir Marzouk, Astronomer at the Qatar Calendar House, said that this day will be equal of length in night and day to almost all the inhabitants of the globe, including the people of Qatar, where will occur the phenomenon of autumnal moderation in the northern hemisphere, while the situation will be the opposite in the southern hemisphere, where inhabitants will have the phenomenon of spring equinox the same day.
Marzouk added that the length of day and night would be almost equal to the people of Qatar. The length of the day on Sunday will be 12 hours and 6 minutes, while the night will be 11 hours and 54 minutes as the Sun will rise this day on the skies of Qatar at 5:23am, while the sunset will be at 5.29pm, Doha local time.
An equinox, sometimes called an evennight, is commonly regarded as the moment when the plane (extended indefinitely in all directions) of Earth's Equator passes through the centre of the Sun, which occurs twice each year: around March20 and September 22, 23. In other words, it is the point at which the centre of the visible Sun is directly above the Equator.
However, because the Moon (and to a lesser extent the other planets) cause the true motion of the Earth to vary from a perfect ellipse, the equinox is now officially defined by the Sun's more regular ecliptic longitude rather than latitude.
The instants of the equinoxes are currently defined to be when the longitude of the Sun is 0 and 180.3. There are tiny (up to 1 arcsecond) variations in the Sun's latitude, which means the Sun's center is rarely precisely over the equator under the official definition. The two understandings of the equinox can lead to discrepancies of up to 69 seconds.
On the day of an equinox, daytime and nighttime are of approximately equal duration all over the planet. They are not exactly equal, however, due to the angular size of the Sun and atmospheric refraction.