Question

Write scientific reason.

Stars twinkle but we do not see the twinkling of planets.

Answer 1

1. Due to the motion of atmospheric air and change in density and temperature, the atmosphere is not steady. As a result, a refractive index of air in a given region changes continuously and randomly.
2. Due to this, the position and brightness of the star keep changing continuously and the star appears to be twinkling.
3. The rays of light from a planet pass through the atmosphere of the earth. As compared to stars, planets are nearer to earth. So a planet can be considered as a collection of a large number of point sources of light.
4. If the intensity of light from one point source decreases, it increases from the other source. Thus, the average intensity remains the same.
   Hence, stars twinkle but we do not see the twinkling of planets.