What atmospheric characteristic distinguishes the light of a planet like Venus from that of a distant star?

Answer

Planets display a steady light, while stars twinkle due to atmospheric turbulence.

Because planets appear as tiny disks rather than perfect points of light, their illumination is less susceptible to disruption by turbulent air pockets, known as 'seeing conditions,' which cause distant stars to twinkle.

What atmospheric characteristic distinguishes the light of a planet like Venus from that of a distant star?
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