NCERT Question 10 - Chapter 11 Class 10 - Human Eye and Colourful World

Last updated at August 17, 2026 by

Why do stars twinkle?

 

Answer

twinkling of stars.gif

 

The change in optical density of air due to the different atmospheric layer causes  twinkling of stars.

  • The twinkling of stars occurs due to atmospheric refraction of star's light.
  • The Optical Density of Air varies continuously in the different layers of the atmosphere.
  • Due to the varying optical densities of air, starlight is refracted multiple times through the atmosphere before it reaches our eyes.
  • As air in the atmosphere moves, this refracted light also shifts, causing shifts in the image of the stars that we see.
  • Hence, the image of the stars in our eyes changes continuously and stars appear to twinkle .

Why do Stars twinkle.gif

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