Before revision: As of 2012, the United States Joint Space Operations Center tracked 21,000 pieces of orbital debris larger than 10 cm in Earth ’ s nearby orbits (LEO, GEO, and sun-synchronous), where 16,000 of these pieces are catalogued.
After revision: As of 2012, the United States Joint Space Operations Center tracked 21,000 pieces of orbital debris larger than 10 cm in Earth ' s nearby orbits (LEO, GEO, and sun-synchronous), where 16,000 of these pieces are catalogued.