A question about our atmosphere

Wasn't sure where I was supposed to post this, so please feel free to move it if it's in the wrong section. Moving on...

A friend and I had a quick little debate on what would happen if a particle the size of three or four molecules (something like that, he wasn't very clear with the size, but let's just say it's pretty darn small) were to hit our beloved Earth. An object that small going at near light speed (roughly 99,9%), what would happen?

1, The Earth would be cleaved into two (or more) pieces. His theory.
2, The "thing", astroid, meteor, whatever it was he was referring to would be crushed by our atmosphere before it reached ground-level, thus not causing any kind of damage. My theory.

Which one is it? Or is it neither of them?

Thanks,
Linus

Happens all the time and we are still here

https://secure.wikimedia.org/wikipedia/ ... Cosmic_ray

some of the cosmic ray particles are helium nuclei or above the atmosphere protects us from most of them butif you or your friend have flown on a plane for any length of time its likely you have been hit by a few. Some astronauts have detected them by seeing the flashes of the cascades they cause in their own eyeballs the early ones did not want to admit it because they thought they might be taken off duty for seeing things.

Thanks for the reply!

It looks like I will not have to worry, then. I'll make sure to pass on the information to my friend.

Cheers,
Linus