21 December 2019 22:35
Saturday marks the winter solstice. What does that mean? Cincinnati may be warming up for Christmas, but Saturday is still scheduled to be the darkest day of the year. The winter solstice is upon us, marking the first day of astronomical winter, the shortest day of the year and the longest night. The reason for the season has nothing to do with earth's distance from the sun, however.
That's a common misconception, according to Miami University associate professor of astronomy and physics Stephen Alexander. The key is in the earth's tilt, Alexander says. He explains that the earth is tilted 23.5 degrees and therefore receives a different amount of direct sunlight at different points as it orbits the sun. When the northern hemisphere is tilted away from the sun, we receive less direct sunlight and a shorter sun arc, creating winter. As the planet completes its orbit we eventually find ourselves tilted towards the sun, creating hotter, longer summer days. [Subscribe now for unlimited access to Cincinnati.com] [Want to stay in the loop on all things Cincinnati? Download our app. The shortest day of the year, then, indicates the epitome of the earth's tilt away from the sun, giving us the shortest sun arc. On this same day, those living down in the southern hemisphere will see their summer solstice: the longest day of the year. The winter solstice will occur at 11:19 p.m. Eastern Time Saturday, the exact moment the northern hemisphere is tilted farthest from the sun. Moving forward the days can only get longer and warmer, astronomically speaking, giving us one more reason to celebrate this week.