What you’re seeing is an object entering the earth’s atmosphere and breaking up on the way down.  The light is where the friction causes the atmosphere to literally burn around the object.  When an object breaks up, it could be because of stresses caused by the atmosphere or it could be there was a pocket of ice holding it together that melts away.  Regardless, it makes a nice lightshow.  Countless objects fall to earth every day, slowly increasing the mass of our planet.  The heaviest period of this activity was approximately 3 billion years ago, when the solar system was much, much dirtier.

Don’t be afraid of something hitting you, though.  Most of this junk is tiny and either burns up completely or lands somewhere completely harmless, like the ocean.  On the off chance it does hit you, you have one hell of a story, because you’ve probably survived due to the object slowing down to terminal velocity.