Planets do not twinkle because

Correct option is C

The correct answer is (C) They act as extended source of light.

• Planets do not twinkle because they appear as extended sources of light to the human eye. Unlike stars, which are point sources of light and more susceptible to atmospheric turbulence, planets have a relatively larger angular size due to their proximity to Earth.
• The light from a planet is an average of the many beams coming from different parts of its disk. This averaging effect minimizes the impact of atmospheric refraction, leading to a steady appearance rather than twinkling.

Key Points:

• Stars twinkle because their light passes through various layers of Earth's atmosphere, where turbulence causes rapid changes in the refracted light's direction.
• Planets, due to their larger apparent size, are less affected by atmospheric refraction and hence do not exhibit noticeable twinkling.
• This phenomenon is why planets generally appear as steady points of light in the night sky.