More than 500,000 particles of space junk the size of a marble or larger now orbit the Earth, posing potential dangers to the International Space Station (ISS), satellites, and other spacecraft that leave Earth’s atmosphere.
The debris is comprised of launch, satellite, and rocket parts jettisoned by spacecraft since Russia launched Sputnik in 1957.
“Almost every mission into space has created new debris, either from the launch vehicles, objects falling off satellites, or unintended collisions,” noted John Bohannon, a writer for the journal Science.
Stuart Gray, an astronomer at University College London, used data from SpaceTrack.org, a US Air Force program designed to keep track of space probes and artificial satellites, to create an animated visualization depicting the accumulation of space junk in Earth’s orbit from 1957 to today.
The visualization depicts all debris the size of an apple or larger, approximately 20,000 objects though their sizes are not too scale.
The largest object in the visualization is approximately the size of a bus, Grey said.
An apple-sized object traveling at 17,000 miles per hour can tear through a wall of steel, Bohannon said, emphasizing the degree of damage that can be done to a spacecraft.
Approximately 2,000 pieces of debris were added to Earth’s orbit in 2007 and again in 2009.
The 2007 debris was produced by an explosion during a Chinese ballistic missile test. Two years later, the same amount of debris resulted from a collision between two satellites.
While some of the space junk could fall back to Earth, the chance of this happening is unlikely. The debris poses a far greater risk to spacecraft that leave Earth’s atmosphere.
Every year, the ISS has to conduct a few maneuvers to avoid being hit by debris.
Grey’s visualization can play a role in cleanup efforts because it will help scientists better understand the scope of the problem.
A new, more sophisticated Air Force radar system with the ability to track even smaller objects is currently under construction and expected to be functional by 2019.
At least two methods for cleaning up space junk have been proposed. Swiss researchers are developing a tiny satellite capable of “eating” up debris particles.
A team of researchers led by Toshikazu Ebisuzaki of Japan’s RIKEN research institute propose placing a fiber optic laser on the ISS, which could then be fired at incoming debris.