Lithium Trail in Upper Atmosphere Traced to SpaceX Re-entry
Researchers using sensitive lasers detected a rapid lithium plume in the mesosphere–lower thermosphere and traced it to the February 2025 re-entry of a discarded SpaceX Falcon 9 upper stage, marking the first ground-based observation that re-entering space debris leaves a detectable chemical fingerprint. With orbital activity rising and megaconstellations planned, the study underscores the need for monitoring networks and regulatory action to understand and manage potential impacts on the upper atmosphere and ozone.