Space debris from rocket bodies orbiting Earth is posing an increased threat to aircraft while falling from space, according to new research.
While the probability of space junk striking an airplane is low, the risk is rising due to increases in both the aviation industry and the space flight industry, according to a paper published in Scientific Reports.
Space junk originates from everything that is launched by human access to outer space -- including satellites and equipment for exploration, Aaron Boley, an associate professor of physics and astronomy at the University of British Columbia and co-director of the Outer Space Institute, told ABC News. Rockets are used to insert satellites into orbit, and a lot of material gets left behind.
"Now that we have such growth in our use of outer space, a lot of the problems associated with that are coming to bear," said Boley, one of the authors of the paper.
MORE: Two North Carolina men find suspected space debris from same craftThere are probably about 50,000 pieces of space junk the size of a softball or larger floating near Earth, Boley said. When considering objects between a centimeter or half a millimeter, the number is likely in the millions, he said.
The objects in orbit are naturally decaying, much of it "uncontrollably," Boley said.
"When they re-enter, they break apart and they do not demise entirely in the atmosphere," Boley said.
MORE: Is Musk's Starlink polluting space? Researchers call for the FCC to pause launchesWhen those objects re-enter Earth's atmosphere, they tend to ablate. As the material burns up, it melts and vaporizes -- basically turning into fine particulates, Boley said.
The study focused especially on rocket bodies due to their size. Rocket bodies tend to be massive and heat resistant and pose casualty risks for people on the ground, at sea or in the air.
The research broke down the risks depending on regions of airspace by tracking the highest density of air traffic using 2023 data. Places like Vancouver, Seattle and the Eastern seaboard had about a 25% chance each year of being disrupted by re-entry of space debris, the paper found.
MORE: There's a small chance an asteroid could hit Earth within the next decade, says NASAOfficials will be able to use that data to determine whether closing airspace is prudent, the authors said.
"Someone has to decide whether they're going to roll the dice and say this is such a low probability that we don't need to take any action or out of the abundance of cautiont," Boley said.
Conversely, taking action and closing down airspace could cause economic disruption and possibly cause other safety issues by diverting flights, Boley added.
Ensuring aviation safety in context of a potential space junk strike was not taken into consideration until the 2003 Columbia space shuttle disaster, in which the spacecraft broke apart while re-entering the atmosphere.
"Aircraft were flying through that debris after it had broken apart," Boley said. "...After the fact, when there was the post-analysis, they realized that that was actually a big safety issue for the aircraft in flight."
The aviation industry is taking space debris into more consideration when making decisions to close airspace. In 2022, Spain and France closed some of the countries' airspace when a 20-ton rocket body was about to reenter the atmosphere, according to the paper.
The rocket body ended up plummeting into the Pacific Ocean, the researchers said. The closure delayed 645 aircraft for about 30 minutes and diverted some of the planes that were already in the air.
"This disruption is definitely happening, and it's going to be happening more," Boley said.
