Asteroids are not a big deal, it's only when they're the really big ones that they're a problem, little ones from the size of a grain of rice to the size of a basketball hit the atmosphere all the time and you don't see people worried or freaking out about those.
Meteorites are ones that get through the atmosphere, I'm talking about ones that burn up in the atmosphere. Those are called meteors (shooting stars) though the very small ones most often won't be visible.