How does a calendar keep the seasons in place?
Calendar's Cosmic Dance
How does a calendar keep the seasons in place?
Every year, summer arrives in June, autumn shows up in September, and winter rolls in right on schedule in December. How does the calendar know when to flip the seasons? Here's the secret: it doesn't. The calendar doesn't boss the seasons around — it's the other way around.
The seasons happen because Earth tilts. Our planet spins like a top, but instead of standing straight up, it leans to one side — about 23 degrees, like a beach umbrella someone forgot to push all the way into the sand. That tilt stays locked in place as Earth travels around the sun.
