Astronomy of Jeddah: beginning of winter 2018 … next Saturday

Jeddah – harmony:

The winter solstice will be held this year on Saturday, December 22 at 1:23 pm (22:23 GMT), a sign of the beginning of winter in the northern hemisphere, said Majid Abu Zahra, president of the Astronomical Society of Jeddah.

This year will coincide with the winter solstice and the appearance of the moon in full moon phase. This association is another time in 2010 and will be next in 2029.

The winter solstice causes the axis of the earth to move around the sun, and as the earth revolves around the sun, it is not vertical but 23.5 degrees in diameter, the northern half and the half South exchange their rays to receive the sunlight. In the occurrence of the four seasons.

On the day of the winter solstice, the north pole is tilted away from the sun and seems to reach the maximum point south of the sky, just above the orbit of Capricorn. H.

However, the northern polar circle at 66.5 degrees north latitude has no sun to get up or set on the day of the year of the winter solstice, because the sun stays under the horizon all day, while the polar circle is at 66.5 degrees of latitude. A degree south of the equator will not detect either sunrise or sunset, as the sun stays above the horizon all day and is called the midnight sun.

On the day of the winter solstice, dawn rises and the sun rises from the far south-east. The arc of the apparent path of the sun in the dome of the sky is low and at noon, "shadow" is the shadow of things at its maximum length during the year.

Before the rising of the winter solstice, the dawn sky is now spotted by Venus, in addition to Jupiter and Mercury, who seem to be close to each other in the dome from the sky to the horizon is, preferably with the help of a binocular telescope to find Mercury near Jupiter.

After the arrival of the sun, the maximum point south of the "apparent" sky at the winter solstice will be observed as it was rising from a point south of the sky for several days before resuming its apparent course to the north as a result of the movement of the Earth in its orbit around the Sun, so as to equate the night with the spring equinox of March 21, 2019.