In 1957, the discarded rocket that carried the Soviet Union's Sputnik 1 satellite into orbit became the first piece of space trash. Today, pieces of space debris total in the thousands.

NASA reports that as of 2013 there were more than 500,000 pieces of space junk the size of a marble or larger. Nearly 20,000 pieces are bigger than a softball -- tracked by NASA, ESA and others.

With every new launch or retired satellite, small pieces are added to the orbital trash heap. Just last spring, a NOAA weather satellite exploded into 43 pieces.

Recently, Stuart Grey, a researcher at the University College London, created a map of all of Earth's traceable space debris, using data on the junk's location from space-track.org. Grey has been locating and modeling the trajectory of space debris for several years as part of his research at UCL's Space Geodesy and Navigation Laboratory.

The new video and orbital model features only 20,000 softball-size pieces of junk, not every loose screw or fleck of paint around Earth -- which are harder to track.

Even a small piece of space trash traveling at speeds upwards of 17,500 miles per hour can do serious damage to the International Space Station, satellite or other space vehicle.

Engineers at NASA and other space agencies have been looking at ways to rid Earth's neighborhood of trash. Scientists have proposed everything from giant nets to trash-seeking lasers.