You might be a little disconcerted by what we're about to tell you. Right this minute your body is being shot through billions of times.
Pretty weird, huh? The culprit is a particle called the neutrino.
Neutrinos come from the sun. They are the result of nuclear processes that take place in the sun's core, the same processes that cause the sun to give off light.
The funky thing about neutrinos, though, is that they have no charge and almost no mass. Whether their mass is actually zero or just extremely close to zero is a hot topic. However, this much we know: because it has no charge and is virtually massless, a neutrino can zip right through your body without hitting anything.
Think of it this way. When a tennis ball hits the racket it bounces back, even though the screen in the racket has lots of empty space in it. A golf ball would still bounce back, but a bee-bee would probably fly right through without hitting anything. A neutrino is like that. It can pass right through what seems like solid matter to us without hitting any of the atoms or electrical fields that make it up. Sure, every now and again a neutrino might hit something, just like a bee-bee might hit the mesh of a tennis racket. But the chances are pretty slim.
So slim, in fact, that not only have billions of neutrinos passed through your body while you've been listening to this, almost all of them continued on entirely through the earth and out into space, without touching a thing.