Stars Twinkle

Stars twinkle due to turbulence in the Earth's atmosphere. Thick layers of turbulent , it is an moving air in the earth’s surface.

Since the atmosphere is made up of several layers, each layer has a different temperature and density, and as the light from a star passes through the atmosphere, it bends through each layer and this is what we recive as twinkling.

We see this because of light's passage through layers of air with differing temperatures, pressures, densities, moisture content and other factors. All of them will have a subtle effect on the light, and it will "waver" a bit so that we get a "twinkle" when we look at the stars. Temperature differences are well known for distorting light, and the "heat waves" we see when objects are viewed through air with differing temperatures in the path of the light are things we can generally recall. On a hot day, air above the heated surface of a dark colored vehicle appears to "shimmer" because of the "heat" rising from the vehicle.

Light from the stars came a long way to get here for us to see it, but it is its passage through earth's atmosphere that gives it the greatest difficulty. And we see the difficulty the light has getting through the atmosphere 'cause it just can't stay in a straight line. The small "shifts" the light takes in its travel appear as the "twinkle" of the stars.

The apparent twinkling of stars is actually caused by our atmosphere. As light passes through it, it is slightly interfered with. The lower a star is, the more atmosphere its light is having to pass through, so stars nearer the horizon seem to twinkle a lot more than those higher up or overhead.