Overview
- A resonance lidar in northern Germany measured a sudden lithium layer at roughly 94–97 kilometers shortly after 00:20 UTC on February 20, 2025.
- The enhancement reached about 10 times the background concentration and remained in the instrument’s view for approximately 27 minutes.
- Atmospheric transport modeling linked the plume to an uncontrolled Falcon 9 upper-stage breakup over the Atlantic west of Ireland hours earlier.
- Researchers report the first ground-based observation directly attributing an upper-atmospheric pollutant plume to a specific re-entry, while noting many species may evade lidar detection.
- Scientists say effects on ozone and climate remain uncertain as active satellites number around 14,000 and filings envision far larger constellations without dedicated regulations or a monitoring network.