Updated for 2021!
Tuesday, September 22, 2021 at 19:21 UTC (which is the same as 3:21 am EST), will be the Autumnal Equinox. It is the time of year when the imaginary plane that passes 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 over much of the Earth. In the Northern Hemisphere we move into the Fall season.
We have three possible activities for you to use in your classrooms.
- Autumnal Equinox-chart2021.pdf - What can you deduce about the Autumnal Equinox from this line graph?
For members we have supplied some of our thoughts: Autumnal Equinox-chart2021-thoughts.pdf
- Autumnal-Equinox-3-latitudes2021.pdf - How are the daylight hours of these three latitudes different and the same?
For members we have supplied some of our thoughts: Autumnal-Equinox-3-latitudes2021-thoughts.pdf
- Autumnal-Equinox-using-trig2021.pdf - Calculate daylight hours for any latitude with a formula involving trigonometry.
For members we also have our spreadsheet and charts: daylight-hours-N40.xlsx
CCSS: 5.G.A.2, 7.G.A.3, 8.SP, HSF.IF.B, HSG.MG.A.1, MP3, MP4