BETHLEHEM, Pa. — Brad Klein reviews upcoming astronomical highlights with Bethlehem’s ‘Backyard Astronomy Guy,’ Marty McGuire.
This week marks the start of astronomical winter which began with the December solstice, Sunday morning just after 10 a.m. EST.
The change of seasons takes place due to the tilt of Earth’s axis, relative to its orbit around our sun, and the December solstice occurs at the moment that the North Pole reaches its maximum tilt away from the sun.
The solstice is also the day with the longest night of the year, and the shortest period of daylight. But don’t expect to notice the days suddenly getting longer right away. The change in sunrise and sunset is very slight around the solstices, just a few seconds per day.
That change accelerates as we approach spring, and the total effect is quite dramatic. This week, we have only about 9 hours between sunrise and sunset.
“And at the peak of the longest day of the year, it's almost 15 hours,” according to McGuire.
