There are currently more than 8,000 internet satellites in low-earth orbit
Internet satellite networks like Elon Musk's Starlink could be depleting the Earth's ozone layer, researchers from the University of Southern California have claimed. The research published in the journal Geophysical Research Letters claims that SpaceX's Starlink spew copious amounts of aluminium oxide gas in the atmosphere that could deplete the ozone layer.
Notably, the ozone layer is vital for our survival. It absorbs harmful ultraviolet radiation from the Sun, which can cause skin cancer on exposure and even disrupt crop yields and food production.
"Only in recent years have people started to think this might become a problem. We were one of the first teams to look at what the implication of these facts might be," said co-author and University of Southern California astronautics researcher Joseph Wang in a statement.
Internet satellites in low Earth orbit have a short lifespan of about five years. There are currently more than 8,000 internet satellites in low-earth orbit, of which about 6,000 are Starlink ones. These satellites are designed to burn up in the atmosphere when their service lives end, researchers said. As a result, they could spew over 1,000 tons of aluminium oxide annually, a 646-per cent increase relative to natural levels. Aluminium oxides deplete ozone by causing it to react destructively with chlorine.
"Satellites burn up at the end of service life during reentry, generating aluminium oxides as the main byproduct. These are known catalysts for chlorine activation that depletes ozone in the stratosphere," the researchers wrote.
"We find that the demise of a typical 250-kg satellite can generate around 30 kg of aluminium oxide nanoparticles, which may endure for decades in the atmosphere," they added.
The study further found that the presence of the oxides increased roughly eightfold between 2016 and 2022 and could surge far more with current satellite launch plans.
As per Independent, SpaceX alone has permission to launch another 42,000 Starlink satellites while Amazon and other tech giants also plan to launch thousands of satellites in the coming years.
The rapid increase in satellite numbers also raises concerns about space debris, which can cause collisions and damage other satellites.