There are literally thousands of artificial "satellites." The US.Space
Command's Space Surveillance Center near Colorado Springs,
Colorado, monitors the whereabouts of more than 7,000 artificial objects, A few hundred are working satellites and spacecraft, but thousands more are spent rocket boosters, shards from exploded rockets, chunks of solar panels, screws and tools from previous space missions, and several thousand defunct satellites.
This space debris (depicted below as yellow dots) is becoming a big safety issue. A fleck of paint moving at speeds of 17,000 miles per hour (27,000 km/h) has the energy to chip a space shuttle 'window or pierce the skin of a satellite. Imagine how damaging and dangerous an errant screw or a large piece of metal could be moving at that velocity.
Objects in low Earth orbit reenter the atmosphere arid burn up after a few months. Objects at greater altitudes-could remain in orbitfor centuries. Each piece of debris must be diligently tracked to avoid harm to spacecraft.