A research aircraft flying through the Earth’s stratosphere has identified over 20 elements related to the aerospace industry. Experts predict that this issue could worsen in the future.
Will the Earth’s Atmosphere Change Significantly in the Future?
A new study reveals that the sky is filled with metal pollution from space debris burning up as it re-enters the atmosphere. Researchers warn that this surprising level of pollution, which is likely to increase sharply in the coming decades, could alter our planet’s atmosphere in ways we have yet to fully understand.
The study, published on October 16 in the journal PNAS, is part of the Stratospheric Aerosol Budget and Radiative Effects (SABRE) mission by the National Oceanic and Atmospheric Administration (NOAA) of the United States, which monitors the levels of aerosols—tiny particles suspended in the air—in the atmosphere.
Illustration of a satellite burning up as it re-enters the Earth’s atmosphere. (Photo: PaulFleet via Getty Images).
The research team utilized a research aircraft equipped with a specialized funnel on its nose to collect and analyze aerosols to sample the stratosphere—the second layer of the atmosphere extending from 12 to 50 km above the planet’s surface.
The study was designed to detect aerosols covered by “cosmic dust” left by meteors that burn up upon entering Earth. Instead, the aircraft detected high levels of metallic elements contaminating the suspended particles, none of which could be attributed to meteors or other natural processes.
Confusion with Rare Earth Metals
The two most surprising elements were niobium and hafnium, both of which are rare earth metals used to manufacture technology components such as batteries. Researchers were also puzzled by the high levels of aluminum, copper, and lithium.
The lead author of the study, Daniel Murphy, an atmospheric chemist at the NOAA Chemical Sciences Laboratory in Boulder, Colorado, stated that the research team did not expect to find these elements in the stratosphere and were initially confused about their origins.
He said: “The combination of aluminum and copper, along with niobium and hafnium, which are used in high-performance, heat-resistant alloys, pointed us towards the aerospace industry.”
Researchers wrote in a statement: “This finding is the first to show that stratospheric pollution is definitely linked to the re-entry of space debris.”
In total, the study identified 20 different metallic elements that do not naturally occur in the Earth’s atmosphere, including silver, iron, lead, magnesium, titanium, beryllium, chromium, nickel, and zinc. The research team suspects that the primary source of pollution is rocket boosters emitted just after they escape the upper atmosphere, then fall back to Earth.
China, a country previously criticized for a series of uncontrolled rocket booster re-entries, faces similar issues along with Russia and NASA.
Pollution from Satellites?
Abandoned satellites, those knocked off orbit by solar storms, or intentionally crashed back to Earth also have the potential to release large amounts of metallic pollution as they burn up.
Pollution from satellites is likely to increase as more commercial satellites are launched into space. Of particular concern is the nearly 9,000 satellites currently in low Earth orbit, all of which are destined to fall back to Earth.
Overall, about 10% of the aerosols from the new study were contaminated by metallic space debris. However, researchers predict that this proportion could rise to about 50% in the coming decades.
It is still too early to determine the long-term effects that this pollution will have on our planet. However, past atmospheric pollution, such as chlorofluorocarbons (CFCs), has contributed to the creation of holes in the ozone layer.
