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How and why?

Cartoon of tides bulging on opposite sides of Earth as seen from North Pole.

What causes tides?
Cartoon of Earth's atmosphere.

How did Earth's atmosphere form?
Photo of Earth's atmosphere from space.

Why doesn't Earth's atmosphere just float off into space?
Cartoon of newly formed Earth being hit by large object, knocking it off kilter.

Why do we have seasons?
Drawing of waves of different colors that together make white visible light.

Why is the sky blue?
Cartoon swirl pattern symbolizing hurricane.

How does a hurricane form?
Cartoon travel brochure for Venus.

How's the weather on other planets?
Cartoon Sun about to burp out a solar flare.

How does weather on the sun affect Earth?
Cartoon barometer.

How can I do a science fair project?

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