Why stars twinkle but planets don't? I am not from a physics background. I came to know this while studying probability? Is this because the planets are nearer than the stars so we get average behaviour rather than random. Is law of large number used here? Can anyone explain in detail.
Why do stars flicker? Why do stars flicker and planets don't? At least this is what I've read online and seen on the night sky. I've heard that it has to do something with the fact that stars emit light and planets reflect it. But I don't get it, isn't this light, just "light"? What happens to the reflected light that it doesn't flicker anymore?  I was thinking that it has to do something with Earth's atmosphere, different temperatures or something (if this has any role at all).
What is the typical orbital life of an artificial satellite? The orbit of satellites around Earth eventually decays, or so I read. This is typically caused either by atmospheric drag, or by tides. I would assume most satellites have a limited service life in orbit. Hence the question - What is the typical orbital life of a satellite? How long before it's successor must be launched into orbit ?  EDIT: For instance, a weather satellite