A Wonderleaf question
Why does Earth spin?
a real page from the book
Earth spins because it formed from material that was already turning. As a young cloud of gas, dust, and rock pulled together under gravity, that turning motion stayed with it. Our planet kept the inherited spin, and space has little friction to slow it down quickly.
A huge early crash also changed the story. A planet-sized body, often called Theia, struck young Earth, helping form the Moon and altering Earth's rotation and tilt. That tilt is one reason different places lean toward or away from the Sun through the year.
Wonder words
- gravity
- friction
- momentum
- tilt
Try it out
Spin a coin on the table, watch it slow, then imagine how long it would turn with almost nothing rubbing against it.
Read the whole picture book
Watercolour scenes, straight answers, about three minutes cover to cover.
Open the picture bookKeep wondering
One more wonder: Why is space so dark?
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