Question

Which phenomenon is responsible for twinkling of stars?
1. Scattering of light
2. Dispersion of light
3. Total Internal reflection
4. Atmospheric refraction
5. All of the above

Answer 1

Correct Answer - Option 4 : Atmospheric refraction

Option 4 is correct:

• Twinkling of stars is mainly due to Atmospheric refraction.
• The light from the stars gets refracted as they pass through different mediums when they come in contact with the wind and different temperatures and densities in the atmosphere.
• When a ray of light travels from one medium to another it ‘bends’, this phenomenon is referred to as refraction.
• If it travels from a rare medium to a dense medium, it bends towards the normal and if it travels from a dense medium to a rarer medium, it bends away from the normal. 
• The speed through which it travels changes depending on the medium and therefore this bending occurs.
• Planets do not twinkle like stars because the distance between the planets and the earth is not far when compared to the distance between the stars and the earth.