Leave No Trace?

The military command keeping an eye on events like last week's Chinese missile defense test says the incident has left no measurable debris floating around in orbit.

As of Friday last week, officials were "not tracking" any debris as a result of the test, a U.S. Strategic Command spokesman told us today. The spokesman said there was debris in space immediately after the event, but the parts entered the Earth's atmosphere within 10 minutes.

In a widely reported statement following the Jan. 11 test, a Pentagon spokeswoman said military officials "detected two geographically separated missile launch events with an exoatmospheric collision also being observed by space-based sensors."