Because strong solar storms from the Sun cause them to burn up and fall earlier than expected.
This raises the risk that some satellite parts might not burn up fully and could reach the ground, as per reports. A piece of a Starlink satellite actually crashed onto a farm in Canada in August 2024. This is the only known case so far of debris reaching Earth。
Because strong solar storms from the Sun cause them to burn up ...
Yesterday I watched an educational video by "Space Buddy" explaining how low-orbit satellites can be forced into early atmospheric burn-up due to solar storms. Another common scenario is end-of-life deorbiting - like SpaceX's ("Ma Ma" in Chinese) satellites that automatically burn up after their 5-year design lifespan expires. Then there's the more dramatic third option - the kind of violent disassembly seen in Russia's ("Big Bear") anti-satellite tests where missiles go "boom!" and blast them to pieces.