Scientists at the University of Southern California's Department of Astronautical Engineering warn that the proliferation of internet satellites, notably Elon Musk's Starlink, could contribute to the depletion of the ozone layer.
A study published in the peer-reviewed journal Geophysical Research Letters highlights the potential for damaging chemical reactions in the atmosphere caused by the incineration of these satellites upon re-entry.
The current count of low-earth orbit satellites exceeds 8,000, with Starlink accounting for around 6,000. These satellites, predominantly composed of aluminium, are designed with a short operational lifespan of around five years. Upon re-entry, the satellites burn up, producing aluminium oxide, which the study indicates is highly destructive to the ozone layer.
The research found that the concentration of these oxides increased approximately eightfold from 2016 to 2022 and is expected to surge further with ongoing satellite launches.
More satellites launching
SpaceX, the parent company of Starlink, plans to deploy an additional 42,000 satellites. Other companies, including Amazon (NASDAQ:AMZN), are also planning their own substantial satellite launches, which could exacerbate the issue.
The study estimates that 18.7 tonnes of aluminium oxide nanoparticles were released into the atmosphere in 2022 and this figure could rise to 397 tonnes annually, posing a significant threat to the ozone layer.
The strategy of deploying numerous small satellites in low-earth orbit aims to facilitate faster data processing. This contrasts with earlier, higher-orbit satellites that offered slower internet speeds but had longer lifespans.
Since its first experimental satellite launch in 2019, Starlink has rapidly expanded, providing critical internet services globally, including vital communications for Ukraine's defence.
However, the environmental impact of this technological advancement is raising concerns. The study's authors warn that the growing presence of aluminium oxides could hinder the recovery of the ozone layer, which has been gradually healing since the 1987 ban on chlorofluorocarbons (CFCs). This setback could undermine decades of progress in mitigating ozone depletion.
In 2023, the European Space Agency observed a significant hole in the ozone layer over Antarctica, measuring three times the size of Brazil. While the cause remains uncertain, the potential impact of satellite burn-up on ozone depletion is becoming a critical area of concern. Starlink has not yet commented on the study's findings.