For the first time, scientists have directly observed metal pollution resulting from the reentry of a rocket, specifically a SpaceX Falcon 9, into Earth’s atmosphere. This significant observation was reported on February 19, 2025, in the journal Communications Earth and Environment. The findings are crucial as they highlight the potential environmental impact of space debris, which has become increasingly prevalent due to the surge in satellite launches over the past decade.
The study reveals that materials released during the reentry of space debris can harm the ozone layer. Researchers have noted that since the dawn of the space age nearly 70 years ago, the number of satellites and related equipment in orbit has skyrocketed. Private companies, particularly SpaceX, plan to further increase this number, with the Starlink system expected to deploy over 40,000 satellites in low-Earth orbit. Currently, nearly 10,000 satellites are operational.
Each satellite has a planned operational life of approximately five years, after which it burns up in the upper atmosphere. This process releases metals such as lithium, aluminum, and copper, which may catalyze chemical reactions detrimental to the ozone layer. A 2023 study indicated that around 10 percent of stratospheric particles contained pollutants originating from burnt-up satellites and rocket stages, prompting researchers to further investigate the direct impact of such debris.
Observations Over Germany and the UK
On February 19, 2025, researchers observed a plume of lithium approximately 100 kilometers above Germany, emanating from the disintegrating upper stage of a Falcon 9 rocket. The rocket reentered the atmosphere over Ireland and the United Kingdom. According to Claudia Stolle, a meteorologist at the Leibniz Institute of Atmospheric Physics in Germany, “A few hours after the reentry of this rocket, we could see 10 times more lithium than we would have observed otherwise.”
The research team utilized lidar technology, which emits laser pulses tuned to specific wavelengths that reflect off materials like lithium. This advanced measurement method allowed them to track the contamination’s movement through atmospheric simulations. The prevailing winds carried the lithium plume from the North Atlantic to the area above Kühlungsborn, Germany, where the lidar system was located.
Future Implications of Space Debris
While there is a natural influx of metals into the atmosphere from meteorites, the researchers concluded that the overall contribution of reentering space debris could increase metal pollution by as much as 40 percent in the future. As more companies and nations express interest in launching satellites, tracking these contaminants and understanding their effects will become increasingly vital.
“All of them will burn up sooner or later,” Stolle emphasized, underscoring the importance of monitoring the environmental impact of space activities. As the industry evolves, the implications for atmospheric health and the ozone layer will require close scrutiny to mitigate potential harms from metal pollution related to rocket reentries.
