Overview
- Researchers in northern Germany detected a roughly tenfold spike in lithium atoms about 20 hours after a Falcon 9 upper stage reentered on February 19, 2025.
- The lidar observed the plume between 94 and 97 kilometers for about 27 minutes, and wind-model back-trajectories matched the rocket’s reentry path over the Atlantic west of Ireland.
- The team estimates the plume contained around 30 kilograms of lithium, with far larger amounts of aluminum expected from aerospace alloys during burn-up.
- Scientists warn vaporized metals, notably aluminum forming aluminum oxide particles, could affect ozone chemistry and seed high-altitude clouds, though the magnitude of impacts remains uncertain.
- The study in Communications Earth & Environment demonstrates a way to monitor reentry emissions as satellite fleets grow, prompting calls for expanded observations and atmospheric-chemistry modeling.