Why do planets like Venus appear to shine with a steady light rather than twinkle?

Answer

Because they appear as tiny disks, which are less easily distorted by atmospheric turbulence.

Stars twinkle because they are point sources whose light is easily distorted by atmospheric turbulence. Planets, being closer, appear as small disks whose light emits a more steady illumination.

Why do planets like Venus appear to shine with a steady light rather than twinkle?
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