Teaching overview

Learning points

  • On the day of the autumnal equinox, the number of hours of daylight and darkness are equal.
  • The autumnal equinox is usually on September 22 or 23.
  • After the autumnal equinox, animals and plants react to the longer nights by preparing for hibernation or shedding their leaves.

Curriculum keywords

  • Seasons
  • Earth

5 things you didn't know

Day and night

1. On the day of the autumnal equinox, the number of hours of daylight and darkness are almost equal.

Equinox dates

2. The autumnal equinox usually falls on September 22 or 23, but in 1931 it fell on September 24.

September 24

3. The next time the autumnal equinox will fall on September 24 will be in 2303.

Hibernation

4. Animals and plants react to the increasing hours of darkness after the equinox by preparing for hibernation or shedding their leaves.

Shedding leaves

5. Trees in one acre of forest can shed as much as 2000 kg of leaves during fall. That’s nearly as heavy as two giraffes!

Spark a discussion

  • What is the autumnal equinox?
  • The hours of daylight and darkness are equal on the autumnal equinox. Do you think this will be similar or different to the spring equinox?
  • Imagine you're an animal preparing to hibernate. How would you get ready?

Twig Science: A Complete Pre-K–8 Program for the NGSS

Immersive Investigations with High-Quality Multimedia

  • Investigating, designing, building, and understanding phenomena
  • Hands-on, digital, video, and print investigations
  • Synchronous/asynchronous distance learning