It's the winter solstice. Here are 5 ways people celebrate the return of light

On Yalda night, the Iranian winter solstice tradition, observers gather with family and read classic poetry aloud to greet the returning sun. (Jasmin Merdan/Getty Images)

It's officially the start of a new season. Winter solstice, which falls on Thursday in the Northern Hemisphere, marks the shortest day and longest night of the year. From now on, the days become longer and nights become shorter.

This year, the solstice occurs at 10:27 p.m. ET, the exact moment the Earth reaches its maximum tilt away from the sun.