Planets don't actually blink. The twinkling or blinking effect we see in the night sky is primarily caused by atmospheric scintillation. Here's how it works:

* Earth's Atmosphere: Our atmosphere isn't perfectly still. It's constantly in motion, with pockets of air at different temperatures and densities.

* Light Bending: As starlight (or light from planets) enters our atmosphere, it's bent or refracted by these different layers.

* Distortion: This bending causes the light to be scattered and deflected in various directions.

* Apparent Flickering: The constant movement of the air and the varying refraction create a shimmering, twinkling effect to our eyes. The light from a planet appears to change in brightness and even color, giving the illusion of blinking.

Stars vs. Planets: Stars appear to twinkle more than planets because they are much farther away. This means the light from a star is more susceptible to the effects of atmospheric turbulence. Planets, being closer, have a wider beam of light reaching Earth, and this makes the twinkling less noticeable.

Other Factors: While atmospheric scintillation is the main reason, other factors can contribute to the apparent blinking of planets:

* Clouds: Clouds can also cause a twinkling effect by scattering and reflecting light.

* Dust: Dust particles in the atmosphere can further distort the light from planets.

In summary: The "blinking" of planets is an optical illusion caused by the interaction of light with Earth's constantly changing atmosphere.