Winter Solstice 2020: What you know about the shortest day of the year

The winter solstice of 2020 at 5:02 am ET / 2: 02 am PT on Monday, December 21, marks the official start of the celestial winter and the shortest day of the year for the Northern Hemisphere. In the Southern Hemisphere, that day is the summer solstice and the longest day of the year.

The 23.5-degree tilt in the Earth’s orbital axis creates the appearance of sunrise and fall over a year. During the winter solstice, the Northern Hemisphere is filtered at the farthest distance from the sun, producing less light and colder temperatures.

It is the tilt of the Earth – not our distance from the sun – that causes winter and summer. In fact, the Earth is closer to the sun in winter than it is in summer.

The solstice isn’t Monday’s only major astronomy event.

During Monday’s “grand joint”, Jupiter and Saturn form a “double planet,” appearing just a tenth of a step apart – or about a dime thick at arm’s length.

This wonder was dubbed the “Christmas Star” in reference to the celestial light that led the three wise men to Jesus in the Christian Bible’s birth story.

Observers can distinguish Saturn and Jupiter from the stars because the planets appear “brighter and firmer in the skies.”