For live links, click to: riverhouses.org/2019-september-equinox
Today is the September equinox — we call it the autumnal or fall equinox in the northern hemisphere, but in the southern hemisphere it’s the vernal or spring equinox. The autumnal equinox is (in astronomical terms) the first day of fall, just as the vernal equinox is (in astronomical terms) the first day of spring.
❡ Little lessons: “Autumnal and vernal are beautiful words. Let’s look them up in our dictionary (riverhouses.org/books).”
Whenever you’re investigating things temporal or calendrical, timeanddate.com is always a good place to start:
The seasons occur because the earth’s axis of daily rotation is not quite perpendicular to the plane of the earth’s annual orbit around the sun (it’s tilted by about 23º). The solstices occur at the points in the orbit when the axis of rotation is tilted either most directly away from the sun (in December, on the first day of northern-hemisphere winter) or most directly toward the sun (in June, on the first day of northern-hemisphere summer). The two equinoxes, in March and September, occur when the earth’s axis of rotation is “sideways” to the sun (so to speak), making the intervals of daylight and darkness equal (or very nearly so).
NASA has a fun educational crossword puzzle for kids that’s filled with seasonal vocabulary — solstices, equinoxes, and more.
What calendrical events and astronomical transitions will you be marking in your homeschool this season? 😊
❡ Thirty days hath September: This is one of our regular Homeschool Terms & Calendars posts (riverhouses.org/topics/calendars). Print your own River Houses Calendars (riverhouses.org/calendars) and follow along with us throughout the year, and add your name to our free mailing list (riverhouses.org/newsletter) to get great homeschool teaching ideas delivered right to your mailbox every week. 🗞 🗓