Harvest Moon Adventure!
Have you ever looked up at night and seen a HUGE, bright moon? Sometimes, around the start of fall, there's a special full moon called the Harvest Moon. Let's find out why it's so special!
What is the Harvest Moon?
The Harvest Moon isn't a different *kind* of moon, it's just a special name we give to the full moon that happens closest to the beginning of autumn (the autumnal equinox, usually around September 22nd). A full moon is when the whole face of the moon looks bright and round from Earth.
Why Does it Look So Big and Bright?
Sometimes, when the Harvest Moon (or any full moon!) is rising or setting near the horizon (where the sky meets the land), it looks REALLY big and maybe a bit orange or yellow! Why?
- The Big Look (Moon Illusion): Scientists think our brains play a trick on us! When the moon is low, we see it next to things like trees and houses. Our brain compares the moon to these objects and thinks, "Wow, that moon is huge!" When it's high in the empty sky, there's nothing to compare it to, so it looks smaller (even though it's the same size!).
- The Color: When the moon is low, its light has to travel through more of Earth's atmosphere (the air around our planet) to reach our eyes. The atmosphere scatters the blue light, letting more of the red, orange, and yellow light pass through, making the moon look warmer in color.
Why "Harvest" Moon?
Long ago, before electricity and bright lights, farmers needed to work late into the night to gather their crops (harvest them) before winter came. The full moon closest to the start of fall rises around sunset for several nights in a row. This bright moonlight helped farmers see their fields and work longer! That's why it got the name "Harvest Moon." It was like a giant, natural nightlight!
Activity: Moon Observation Chart
Tonight, or the next time there's a full moon (check a calendar!), let's be moon scientists!
- Go outside with a grown-up after sunset when the moon is rising (if you can see it!).
- Look at the moon when it's low near the horizon. What color is it? Does it look big?
- Draw what you see in your science notebook or on a piece of paper. Write down its color and if it looks big or small.
- If you can, look at the moon again later when it's higher in the sky. Does it look different? Draw it again and write down any changes.
Wrap-up
The Harvest Moon is the full moon nearest the start of fall. It often looks big and orange near the horizon because of a cool brain trick (moon illusion) and the way light travels through our atmosphere. It helped farmers long ago by giving them extra light to harvest their crops. Isn't our moon amazing?