The good folks at the Goddard Space Flight Center have cleared up something that's perplexed me for years. According to their website:

You would not be likely to be hit by a meteorite (since it has already hit the ground) unless someone threw one at you.

I am only too painfully aware of the correct nomenclature for such interstellar objects. "Meteoroids" are the countless lumps of rock and metal swarming about in the earth's path. The streaks of light we see as these villains from the vacuum blast through the atmosphere toward their hapless victims are "meteors." After they've done their work and gone to ground, they are known as "meteorites." However, it was never clear to me whether I would be considered the "ground" at the moment of impact. Once flaming space rubble slammed into me, I might as well be.

Now I can at least be scientifically accurate about my fear of being "meteor" bait.

It is true that the object that came though the roof of a New Jersey house last month was at first referred to by all the experts as a meteorite, despite the fact that it ended up on the bathroom tiles rather than the ground. But that is probably irrelevant because it turns out the intruder wasn't either 'roid or 'rite but rather space junk according to the story:

The silvery object was made of a stainless-steel alloy that does not occur in nature and is most likely "orbital debris"-part of a satellite, rocket or some other spacecraft, said Rutgers University geologist Jeremy Delaney.

"There's huge amounts of material that have been left by the various space programs of the world," he said.

The object is slightly bigger than a golf ball and about as heavy as a can of soup.

Who wants to be hit on the head by a soup can dropped from 100 miles up? Space junk is even more alarming than meteoroids. At least the swarms of meteoroids are merely floating around in space waiting for our planet to blunder into their neighborhoods, thanks to Mr Newton's lousy directions. Now it seems we are sitting permanently under an orbiting rubbish heap from which soup cans or golf balls might fall at any minute. Does the Sword of Damocles leap immediately to your mind as well?

To be fair, the object was not specifically identified. It was some of the "orbital debris" that is circling overhead. And what exactly is that? It could mean anything from a pull-tab from a can of freeze-dried chicken salad to a discarded fuel tank the size of a railway box car.

Do you suppose the astronauts on the International Space Station wonder about all those things that go missing? Where's the television remote? Did anyone try looking in Mrs. Greenbaum's kitchen in Parsippany, New Jersey? Right under the big hole in the ceiling? Do astronauts end up with pairs of mismatched EVA boots? Maybe the remains of a boot is sitting in the remains of a house in Schenectady. Better that than a fuel tank the size of a box car. I suppose one might even survive a fiery paper clip.

What can we do? We can't have signs everywhere? "Beware Falling Orbital Debris."

People don't pay attention anyway. When I was a kid my dad used to drive a road that ran along a sheer cliff. Signs at the roadside clearly admonished -- "Beware Falling Rocks." But he kept his gaze resolutely on the highway, oblivious to the menace from above. You can bet I was craning my neck trying to see to the top of the cliffs in case one of those rocks came hurtling down at us.