Overview
- Researchers in Saxony, Germany measured a sharp lithium enhancement roughly 94–97 kilometers high about 20 hours after an uncontrolled Falcon 9 upper-stage reentry on February 19, 2025.
- Back-trajectory modeling linked the plume to the rocket’s path west of Ireland, tying the signal to a fireball widely observed over Europe.
- The team used a dye-laser lidar tuned to lithium, chosen because it is common in aerospace alloys and batteries yet rare in meteoric sources.
- The plume reached around 10 times background lithium and was tracked for about 27 minutes before data collection ended, the study reports in Communications Earth & Environment.
- Scientists describe a proof of concept with uncertain climate or ozone impacts and no regulation targeting upper-atmosphere pollution, as active satellites number about 14,000 and filings have sought hundreds of thousands more.