Winter solstice to bring shortest day in northern hemisphere on Dec 22. How does it occur?

The Winter Solstice is here in the Northern Hemisphere bringing the longest night and shortest day of the year. Every year, Solstices occur twice - once in the summer around June 21-22 and again during the winter season on December 22-23.

The Earth is tilted 23.5˚ on its axis around the Sun which changes the amount of sunlight being received in the northern and southern hemispheres. As explained in the image below (orbit is tilted instead of Earth), when the Earth is tilted farthest away from Earth, it marks the Winter Solstice while it is the Summer Solstice when it is tilted toward the Sun at its maximum.

As a result, when it is the shortest day and longest night in the northern hemisphere, it is exactly the opposite in the south. Notably, all locations in the northern hemisphere witness days shorter than 12 hours. NASA says that the days will be longer and nights shorter in the northern hemisphere until the phenomenon is reversed starting June.

All this while, the southern hemisphere will receive direct sunlight and experience warmer temperatures. 

Interestingly, the winter solstice is the perfect time for stargazing given skies are clear. Currently, five planets-  Mercury, Venus, Mars, Jupiter, and Saturn - can be easily spotted in the clear morning and evening skies.