Longer days will soon be upon us
By Justin GrieserDec. 20, 2020 at 7:22 a.m. MSTAdd to list
Winter may just be getting started, but our long, dark nights are about to turn a bit brighter. Monday is the winter solstice, the shortest day and longest night of the year in Earth’s Northern Hemisphere. On Tuesday, we’ll start gaining a few seconds of daylight again.
This year’s solstice, which arrives Monday at 5:02 a.m. Eastern, coincides with another special astronomical event: On Monday evening, Jupiter and Saturn will be in a rare planetary alignment, appearing closer together in the evening sky than they have in nearly 800 years. They won’t appear this close again until 2080.
The visual proximity of the two giant planets offers a good reason to gaze skyward on the solstice. But if you miss the event (or clouds spoil the show), there’s still plenty to appreciate about the winter solstice in its own right.
What happens on the solstice?
On the December solstice, the sun appears directly over the Tropic of Capricorn, a line of latitude 23.5 degrees south of Earth’s equator. It’s as far south as the sun ever gets before starting its six-month journey northward again. Here in the Northern Hemisphere, we see the sun take its lowest and shortest path across the southern sky, which is why it’s dark for a good portion of the day.
The reason we have solstices, and seasons, is because the Earth doesn’t orbit the sun completely upright. Instead, our planet is tilted on its axis by about 23.5 degrees, which means one hemisphere receives more of the sun’s light and energy at different times of year.
On the winter solstice, the Northern Hemisphere leans away from the sun, and we receive much less direct sunlight. Meanwhile, the Southern Hemisphere is entering summer and people are enjoying their longest day of the year.