December 09, 2013
Gizmo of the Week: Seasons: Earth, Moon, and Sun
While the upcoming December solstice is the shortest day of the year in the Northern Hemisphere, it is not necessarily the earliest sunset. For most locations in the middle latitudes, the earliest sunset occurs a few weeks earlier than the solstice. This occurs because the exact time of solar noon varies slightly throughout the year. At this time of year, solar noon is a bit earlier than on the solstice, resulting in an earlier sunset. (Similarly, the latest sunrise will occur in early January.)
You can observe sunrise and sunset at any date and location with the Seasons: Earth, Moon, and Sun Gizmo. Use the 2D VIEW tab to observe the Sun’s path, or observe sunrise and sunset indirectly with the DAY GRAPH or SHADOWS tabs. You can use the “Step” button and the slowest speed to find the exact times of sunrise, sunset, and solar noon.