The latest Orbital Debris Quarterly News has the good news that, barring another satellite collision or other debris-creating event, the number of catalogued debris should drop over the next two years. The deliberate destruction of the Fengyun-1C satellite in January 2007 created 3,218 pieces of trackable debris, and only about 200 of those have re-entered the atmosphere. As the solar activity increases leading up to solar maximum in 2013, more of that debris should be cleared out. (Note to our readers in the northern latitudes – look for more auroras.)
Speaking of space debris, an experiment from 1963 deliberately placed millions of tiny copper needles in medium Earth orbit. Project West Ford created an artificial ionosphere to help the military, back in the days before communication satellites. The needles were 0.7 inches long and less than half the diameter of human hair (17.8 micrometers). These were the right size dipole antennas for the 8 GHz wavelength used in the study. Most of them re-entered the atmosphere by 1970, but there are still some in orbit today. A spacecraft from an earlier attempt in 1961 is also still in orbit. Protests over this experiment led to the addition of a consultation clause in the 1967 Outer Space Treaty, basically, ask before you do something that might wreck space for the rest of us. Adding more of these dipole antennas could have wrecked radio and microwave telescope observations.