(Photo by Arda Kucukkaya/Anadolu Agency via Getty Images)
A major astronomy group is urging US lawmakers and regulators to investigate the harm Starlink satellites might pose to the environment when they burn up in Earth's atmosphere.
On Friday, the American Astronomical Society flagged the risk of existing and future satellites releasing harmful chemicals in the skies once they’re retired. “The choice to instead burn up satellites in the atmosphere may pose a significant risk to the Earth’s climate and the ozone layer, through the resulting alteration of atmospheric chemistry,” says President Dara Norma.
Astronomer Jonathan McDowell, who tracks Starlink launches, posted about the society’s letter on Monday. It comes as companies like SpaceX are using the Earth’s atmosphere to clear away the remains of retired or malfunctioning satellites. That's because when a spacecraft reenters the atmosphere at high speeds, the surrounding temperatures can reach 5,000 degree Fahrenheit, enough to melt away satellites.
(Credit: ESA)SpaceX and the Federal Communications Commission view atmospheric reentry as a crucial way to prevent space junk from crowding Earth’s orbit. But in its statement, the American Astronomical Society noted “the effects of the expected increase in reentry rates and associated metal pollution are completely unknown” and urged regulators to study the matter.
One concern is that the vaporized metal from the satellites may damage the ozone and other atmospheric properties meant to maintain Earth’s climate. Another worry is the residue “could induce an airglow that increases the night sky brightness,” making it harder for astronomers to make observations.
As a result, the association wrote: “We call on policymakers to provide funding to conduct urgent scientific research in order to provide stakeholders with a timely assessment of all spaceflight emissions and their effects… We further urge regulators to incorporate the results of this research into their licensing of space activities.”
The American Astronomical Society didn’t respond for comment, making it unclear if it sent the statement to US lawmakers or regulators. But in recent years, scientists have been banding together to raise concerns about the rise of "megaconstellations" such as Starlink and their potential to interfere with astronomy.
Although the American Astronomical Society didn’t directly name Starlink, it’s no secret that SpaceX’s internet system currently spans over 6,400 satellites in Earth’s orbit, or about two-thirds of all active satellites. SpaceX, along with its competitors, have also proposed launching tens of thousands of additional satellites in the coming years.
SpaceX and the FCC also didn’t respond to a request for comment. In the meantime, the European Space Agency is preparing to study the issue by deliberately launching a satellite only to watch it disintegrate as it descends back to Earth. However, the mission won’t occur until 2027.