For years, the main way of cleaning up space junk and retired satellites has been to let them burn up as they reenter Earth's atmosphere. For the most part, scientists have always assumed it was relatively safe. Now, though, new research suggests burning satellites up on re-entry is leaving metal particles in the atmosphere.
If scientists are able to prove that the metal particles left behind by burning satellites up in the atmosphere, then we can strive to approach the situation with a better solution — like maybe relying on wooden satellites, something that some space agencies are already testing. Understanding the possible damage that burning satellites could do to the ozone layer is important, though, because that layer is extremely important for the state of our planet's global temperatures.