MEMPHIS, Tenn. (WMC) - The winter solstice marks the official start of winter in the northern Hemisphere which begins this Saturday Dec. 21 at 10:19 p.m. EST. It marks the shortest day and the longest night.
This is due to earth rotating around the sun and the tilting of the earth on it’s axis. It takes the earth 365 days, a year to rotate around the sun. Meanwhile, it is also spinning on it’s axis which takes 24 hours. Earth is tiled 23.5 degrees, this means as it orbits the sun, it changes the way in which it faces it. When it is tilted away it is winter.
During the winter, the sun’s rays hit the Earth at a shallow angle. The sun’s rays are more spread out, which decreases the amount of energy that hits any given spot. The long nights and short days prevent the Earth from warming up. This is why we have winter.
On the other hand, in the summer, the sun’s rays hit the Earth at a steep angle. The light is more concentrated and does not spread out as much, thus increasing the amount of energy hitting any given spot. The long daylight hours allow the Earth plenty of time to reach warm temperatures.
The solstice can occur anywhere between Dec. 20-23 and this year it is on the 21st. The winter solstice marks the minute the sun is directly over the Tropic of Capricorn. Earth is actually closest to the sun.
The word solstice comes from Latin sol “sun” and sistere “to stand still.” On the 21st of December, the sun’s path reaches its southernmost position. While it starts to return north, it gives the appearance of standing still.