Why do stars twinkle?

Why do stars twinkle?

We see the stars through the atmosphere. Their light passes through miles of constantly moving pockets and streams of air, which distort the image we get. The distortions are very small—so small that we don't even notice them when we look at the Moon, or even other planets, like Venus or Mars. Even though stars are much larger than planets, they're so far away from us that they seem smaller in the sky, like itty-bitty points, and the distortions make it seem as if those tiny lights are moving or blinking in and out. In outer space, where there is no atmosphere, stars don't twinkle. This is one reason why the Hubble Space Telescope produces such amazing pictures.

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