News & Updates

Say goodbye to summer: The Northern Hemisphere’s autumnal equinox—the first day of fall—occurs Monday, September 22. With its brilliant colors and crisper days, autumn is a favorite season for many. But what actually happens to make the seasons change? The answer is the “clearly definable” position of the sunon the summer and winter solstices, the late Judith Young, a professor of astronomy at the University of Massachusetts in Amherst, told National Geographic News in 2011. “The solstices are very accurately measured as the northernmost point that the sun rises along the horizon in June and the southernmost point along the horizon in December,” she said. (Seepictures of the sun’s path across the sky—an entire year in a single frame.) In modern times, the solstice points became the astronomical definitions of when the summer and winter seasons begin. In the Northern Hemisphere, June features the summer solstice, while in the Southern Hemisphere, June marks the firs