For many years, scientists have been tracking even the tiniest fragments of space debris orbiting our planet to keep tabs on whether these small leftovers from decades of spaceflight might become a problem, whether for astronauts or for populations here on Earth.
Now, in new research, scientists say they have uncovered dozens of previously undetected fragments of space debris orbiting high above Earth, revealing a hidden population of tiny objects that some liken to a “potential minefield” in space that could pose a growing hazard to some of the world’s most important satellites.
The findings, published in the Journal of the Astronautical Sciences, were carried out by an international team led by researchers at the University of Warwick, who found 25 faint objects in geosynchronous orbit—roughly 36,000 kilometers (22,400 miles) above Earth’s equator.
Close to 80 percent of these newly detected objects had been absent from catalogs available to the public that track such debris, meaning that there could be even more unrecognized leftovers from past space missions circling the Earth than experts realize.
A Problem in Geosynchronous Orbit
Home to a steadily growing number of satellites that we rely on daily for activities here on Earth, geosynchronous orbit is where satellites that govern communication systems, television broadcasting, weather forecasting, and environmental monitoring all reside.
Objects at this altitude remain synchronized with our planet’s rotation, which means that they inhabit what is considered some of the most valuable real estate in space around the Earth.
“Pieces of space junk can be moving very quickly relative to one another, as much as several kilometers every second,” says Dr. James Blake of the University of Warwick’s Centre for Space Domain Awareness, who served as the new study’s lead author. “The energies involved are really high, and even small debris can cause a lot of damage to very expensive satellites, so small things really matter.”
Archival Imagery Reveals New Concerns
Blake and his colleagues didn’t have to collect new observations to make these discoveries: they were able to discover evidence of undocumented orbital debris simply by looking at archival images obtained by the 2.54-meter Isaac Newton Telescope in the Canary Islands.
Offering a new perspective on these archival photos, the team employed a new image processing technique known as “blind stacking,” along with advanced image-processing algorithms, to detect fragments in orbit as small as five centimeters. The detections were significant, as they are now counted among the faintest examples of debris ever observed in geosynchronous orbit.
Naturally, a question arises: how many more examples of tiny debris might be lurking up there?
Tiny Tumbling Troublemakers in Space
Additional analysis of the brightness of these objects revealed another concerning reality: based on variances in the light they reflect, it was evident that many of these objects are tumbling as they make their way through space.
The team’s findings offer a wakeup call in terms of just how much undetected debris may be drifting—or even tumbling—through geosynchronous orbit. However, there is also a positive side to the situation: the team’s discoveries also showcase our growing ability to make such detections if we know how to look for such minuscule objects.
Still, the findings underscore the challenges presented by monitoring orbital debris in a space above the Earth where such materials could potentially linger for centuries, since atmospheric drag in this region of orbit is essentially nonexistent.
“The debris in the neighborhood of the geostationary belt is a potential minefield,” said co-author Dr. Stuart Eves of SJE Space Ltd. “No one in their right mind would enter a terrestrial minefield without a mine detector. Similarly, no one in their right mind should launch a satellite to GEO without an adequate debris survey.”
A Call for International Collaboration
With the project’s reach beyond Europe to include collaboration with researchers in Australia and Japan, the team says that international cooperation will be necessary to track potentially dangerous orbital debris—especially as more and more satellites are being placed in orbit above the Earth.
Increasingly sensitive surveys will be essential for understanding and mitigating the risks posed by even the smallest fragments of space junk, the team says.
“There are a finite number of orbital slots in the GEO belt,” Blake adds, “so it’s important that we know how much debris is out there, how it behaves, what risks are posed to the active satellites we rely on. Surveys for faint debris help us build a clearer picture.”
The team’s findings were detailed in a new study, “DebrisWatch II: Digging Deeper for Geosynchronous Debris,” which appeared in The Journal of the Astronautical Sciences.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.