What is a chunk of rock or dust from space

It's either a comet or asteriod

If it's small and doesn't cause anybody any trouble, it's a meteor.

Thousands of those fall to Earth every day. Maybe millions.

If it happens at night and you happen to be looking in the sky,

you see a "shooting star".

If it's big enough, it would be called an asteroid. None of those

have fallen to Earth for millions of years. If one did, it would be

a giant headache for everybody on Earth. An asteroid more than

a few miles across could could easily wipe out all life on Earth.