Synopsis
Here is a summary of the key points from the research article:
- Measurements show that about 10% of stratospheric aerosol particles contain aluminum and other metals originating from the reentry and burn-up of satellites and rocket stages.
- Over 20 different metals from spacecraft reentry were detected, including lithium, aluminum, copper, and lead. The ratios of these metals match the alloys used in spacecraft construction.
- The influx of metals like aluminum and lithium from spacecraft reentry exceeds the contribution from cosmic dust.
- Particles containing metals from spacecraft reentry also contain meteoric metals, indicating mixing of the two particle types in the stratosphere.
- Models suggest the metals from reentry accumulate in the polar stratosphere within months, which is where the measurements were made.
- With the large increase in satellites planned, metals from reentering spacecraft could end up in up to half of stratospheric aerosol particles.
- The influence of these metallic particles on stratospheric chemistry and climate is unknown. More research is needed on the impacts and fate of the metals injected into the upper atmosphere by human space activity.
