  Every year, more and more objects are sent to space. While staying in orbit
at high altitudes, objects at low altitudes reenter the atmosphere, mostly
disintegrating and adding material to the upper atmosphere. The increasing
number of countries with space programs, advancing commercialization, and
ambitious satellite constellation projects raise concerns about space debris in
the future and will continuously increase the mass flux into the atmosphere. In
this study, we compare the mass influx of human-made (anthropogenic) objects to
the natural mass flux into Earth's atmosphere due to meteoroids, originating
from solar system objects like asteroids and comets. The current and near
future significance of anthropogenic mass sources is evaluated, considering
planned and already partially installed large satellite constellations.
Detailed information about the mass, composition, and ablation of natural and
anthropogenic material are given, reviewing the relevant literature. Today,
anthropogenic material does make up about 2.8 % compared to the annual injected
mass of natural origin, but future satellite constellations may increase this
fraction to nearly 40 %. For this case, the anthropogenic injection of several
metals prevails the injection by natural sources by far. Additionally, we find
that the anthropogenic injection of aerosols into the atmosphere increases
disproportionately. All this can have yet unknown effects on Earth's atmosphere
and the terrestrial habitat.
