system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do stars twinkle while planets don't?

Also, why do some faint stars seem to disappear when we look directly at them, but can be noticed when we look at a nearby patch of sky?
gpt
Starlight is from so far away, it's essentially a single point of light with near zero diameter. When the atmosphere refracts that light, you can notice it more, because the amount of refraction is greater than the diameter of the source.

Light from planets is refracted too, but since they're a lot closer the source isn't zero diameter, it's just slightly bigger. The refraction is more obscured by the diameter of the light source. 

So, planet light is dimmer light, but coming from a larger diameter source.