Winter Solstice 2020: What You Need to Know About the Shortest Day of the Year

The 2020 winter solstice was officially at 5:02 am ET / 2:02 am PT on Monday, December 21, marking the official start of the astronomical winter and the shortest day of the year at ‘northern hemisphere. In the southern hemisphere, this day is the summer solstice and the longest day of the year.

The 23.5 degree tilt on the Earth’s axis of rotation creates an aspect of the sun rising and setting over the course of a year. During the winter solstice, the northern hemisphere tilts to its farthest distance from the sun, providing less light and colder temperatures.

The inclination of the Earth – not our distance from the sun – is what causes winter and summer. In fact, the Earth is closer to the sun during the winter than in the summer months.

The solstice is not the only major astronomical event this Monday.

During Monday’s “great conjunction,” Jupiter and Saturn will form a “double planet,” which appears at only a tenth of a degree, or about the thickness of a penny at arm’s length.

This phenomenon has been dubbed the “Christmas Star” in reference to the heavenly light that guided the three sages to Jesus in the birth story of the Christian Bible.

Sky observers can differentiate Saturn and Jupiter from the stars because the planets will appear “brighter and more solid in the sky.”