The Science of Fall

In class today, we learned why leaves change color in the fall...

       Plants need sunlight and warmth to make the green chlorophyll in their leaves. If there is little or no sunlight, new chlorophyll is no longer made by the plant.

      When summer is over and the weather starts to cool off, this affects the trees in Washington and many other places around the world.

       In the fall, the days get shorter and there is less sunlight, Without enough sunlight,  the trees stop using photosynthesis to make food. Then, the green chlorophyll dies away. As the green disappears, the beautiful colors of fall appear!

      Guess what? The vibrant reds, oranges and yellows were hiding under the green chlorophyll the whole time!

So, why are our days shorter in fall and winter?

Here is a cool video which explains why the seasons change on earth. 

November Work Sample:

[click here for the printable version]
I can't wait to see your leaves!