Changing Seasons: So Much More Than Temperature!

Happy Autumnal Equinox! Autumna-wha? More on that later, just know that September 22nd is the official beginning of the fall season! In this post you'll find some great resources for explaining the changing seasons to kids, and some pitfalls to avoid.

If you live where the leaves change color you might be seeing some of that happening, and you may be somewhere where the temperature is cooling. What other signs have you experienced as the seasons change? Migrations, plants dying back, fuzzy caterpillars, apples, etc. etc. The days begin to get shorter, with a little less daylight each day...ahhh, now we're getting somewhere. 

Why do the seasons change? 

Do you know what causes the changing seasons? I'll give you a second to think about it.... Got it?

Did you say the seasons change as Earth moves closer and further from the sun? How good do you feel about that answer?

Hate to tell you, but that is incorrect. The good news is- you are not alone. This is probably one of the most pervasive science misconceptions we face. Just remember this- it's all about that tilt.

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Science Misconceptions

For those of us who have taken a science teaching methods course, this is probably a familiar topic. An interesting video that was made quite a while back called, A Private Universe, explores these misconceptions. In what is now a well-known opening scene, Harvard students on their graduation day are asked what causes the Earth to have seasons. Although you have to purchase this video to see it in its entirety, here is a snippet. 

You quickly begin to see that regardless of a high quality education, science misconceptions lurk!

[If you are a teacher, I'd recommend getting your hands on this video. Despite being a bit dated (if you haven't seen anyone dressed like this in real life then you must be younger than me!) the problem still rings true today. Misconceptions are hard to break, even after evidence has been presented otherwise.]

Why Do We Experience Seasons on Earth?

Harvard students take note: It's all about that tilt. The Earth rotates on its own axis as it revolves around the sun. Imagine the Earth is a cherry tomato and we put a skewer through the center. The skewer is the Earth's axis. This axis does not stand perfectly upright, it leans to one side. (Scientists believe at some point we were hit with something big that knocked us off kilter.) Now, maintaining your angle of axis, revolve your skewered tomato around the "sun"- a basketball perhaps. Is the same part of the tomato leaning towards the sun?

by-woodleywonderworks Flickr Creative Commons

The Autumnal Equinox

As the planet revolves around the sun, in what is almost a perfectly circular orbit, there are points of time when the Northern hemisphere receives more direct sunlight than the Southern hemisphere. At this time of the year, the Northern hemisphere is experiencing summer, the Southern hemisphere is experiencing winter, and vice versa. For a great graphic illustrating this concept visit NASA's Space Place page on seasons.

Ok, so what about that whole "Autumnal Equinox" thing? There are 2 points in the year when the hemispheres receive equal amounts of sunlight because for just a short period of time the Earth is "upright" rather than tilted, in relation to the sun. Today we will have the equal amounts of daylight and night time- about 12 hours each. You may have noticed equal and equinox share the root- equ meaning similar. The second equinox is in the springtime, or the Vernal Equinox.

Below are some resources and activities to help students understand the seasons better, beyond the seasonal changes we can observe in nature. Pop Quiz: What are you going to remember? Yup, it's all about that tilt. (See? You could have gone to Harvard too!)

Resources for Teaching and Learning About the Seasons:

• Where is the Sun? Model the changing position of the sun with simple materials
• Dress for the Weather- Preschool level digital interactive for learning 4 seasons
• Kinesthetic Astronomy Lesson- Middle Grades
• NASA Space Place: What Causes the Seasons?
• Annenberg Learner Resources: A Private Universe

If you are teaching or studying about changes that happen in the autumn, you'll want to try this science experiment that helps us understand why the leaves change color.

You also won't want to miss these 20 must-try science experiments for fall!