Even in space, Big Brother is watching. And as far as space debris is concerned, that's a good thing. The U.S. tracked more than 19,000 pieces of debris orbiting Earth this year, according to a State Department report.

While it's an impressive number, those remnants of defunct satellites and other spacecraft represent just a small fraction of the orbital debris actually circling Earth. Some NASA estimates put the true tally at more than 500,000. The trouble is the tracking devices can't follow fragments of debris smaller than 10 centimeters.

“By and large, we know exactly where the bigger parts of space debris are,” says Frans von der Dunk, a space law professor at the University of Nebraska College of Law. “And as a consequence, if they come too close to either a valuable satellite or the space station, it is possible to temporarily move [the spacecraft] a little out of harm's way and then, after the big chunk has passed, to move it back.”