EARLY UNOFFICIAL DRAFT

The membership of the American Astronomical Society carefully watch the
sky, and so are keenly aware of the vastly increasing quantity of metal
is being placed into Low Earth Orbit in the form of megaconstellations
of satellites.
These tens of thousands of new satellites are planned to be replaced regularly
to indefinitely maintain a steady state constellation and the old satellites will be
disposed of by ablation in the mesosphere and stratosphere.
We have grave concerns about how all this re-entering metal is going
to affect our atmosphere.

Based on statements from SpaceX we can infer that
Starlink alone plans for 23 satellite reentries per day. With each
Starlink satellite weighing up to 1250kg and being primarily aluminum, this input
will overwhelm the natural injection of metals into the stratosphere by
meteoroids.  Other satellite operators have comparable plans.

Particles of metal from rocket and satellite re-entries already make up
10% of stratospheric aerosols (Murphy et al. 2023, PNAS). Pollution from
reentries could potentially increase the opacity of Earth's atmosphere,
further impacting ground-based astronomy that is already plagued by
satellite streaks.  This pollution could also cause ozone depletion,
changes in naturally occurring sulfates that regulate Earth's
temperature, and potentially changes in Earth's ionosphere and
magnetosphere (Solter-Hunt 2023 arXiv).

We recommend that regulators and policymakers consider this issue in their
licensing of space activities, and move to cap the total mass of metal in Low Earth Orbit
that will eventually enter Earth's atmosphere, until such time as scientific studies
are conducted to establish that the associated reentry flux is not going to cause
significant adverse environmental changes in Earth's upper atmosphere.