We see the stars through the atmosphere. Their light passes through millions of miles of constantly moving pockets and streams of air, which distort the image of the stars. Even though many stars are much larger than planets, they're so far away from us that they seem smaller, like tiny dots. The distortions make it seem as if the shining lights are moving or blinking. Stars twinkle when we see them from the Earth's surface because we are viewing them through thick layers of turbulent (moving) air in the Earth's atmosphere. In outer space, where there is no atmosphere, stars don't twinkle.