Autumnal Equinox
September 22, 2012 is the Autumnal Equinox. It is the time of year when the imaginary plane that might pass through the Earth’s Equator would also travel through the center of the Sun. At this auspicious moment the number of sunlight hours and night time hours are about the same all over the Earth and in the Northern Hemisphere we move into the Fall season.
We love the seasons and Ecliptic animation developed at the University of Nebraska’s Astronomy Applet Project. Below is a screen shot of the applet. By clicking on the NAAP link, a new window will open and students, or the teacher using a projector, can change the position of the person on the globe and other variables to enjoy a discussion of this auspicious moment .
http://astro.unl.edu/naap/motion1/animations/seasons_ecliptic.html
We have three possible activities for you to use in your classrooms after playing with the Nebraska applet.
- Autumnal Equinox-deducing-from-chart.pdf What can you deduce about the Autumnal Equinox from this chart?
- Autumnal-Equinox-3-latitudes.pdf How are the daylight hours of these three latitudes different and the same?
- Autumnal-Equinox-using-formula-with-trig.pdf Calculate daylight hours for any latitude with a formula involving trigonometry.
- daylight-hours.xlsx Spreadsheet and charts for various latitudes.
CCSS: 5.G.A.2, 7.G.A.3, 8.SP, HSG-MG.A.1
