• Deme
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    9 days ago

    https://phys.org/news/2024-06-satellite-megaconstellations-jeopardize-recovery-ozone.html

    When old satellites fall into Earth’s atmosphere and burn up, they leave behind tiny particles of aluminum oxide, which eat away at Earth’s protective ozone layer. A new study finds that these oxides have increased 8-fold between 2016 and 2022 and will continue to accumulate as the number of low-Earth-orbit satellites skyrockets.

    Those micrometeors aren’t mostly aluminium.

    • Kalcifer@sh.itjust.works
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      8 days ago

      Those micrometeors aren’t mostly aluminium.

      Do you have a source for that? Perhaps I’m misunderstanding you, but I’ve found a number of sources that show that meteorites contain aluminum:

      To be fair, I don’t think any of those claim that any meteorites are “mostly” aluminum. But is that a true requirement?

      • Deme
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        8 days ago

        I did write “mostly” for a reason. Aluminium is used a lot in aerospace due to its low mass. There is a lot of matter falling from space naturally, but the composition is key to the effects that will have on the atmosphere. Satellites, spent stages etc. have different compositions to meteors.

        Over 20 elements from reentry were detected and were present in ratios consistent with alloys used in spacecraft. The mass of lithium, aluminum, copper, and lead from the reentry of spacecraft was found to exceed the cosmic dust influx of those metals. About 10% of stratospheric sulfuric acid particles larger than 120 nm in diameter contain aluminum and other elements from spacecraft reentry. Planned increases in the number of low earth orbit satellites within the next few decades could cause up to half of stratospheric sulfuric acid particles to contain metals from reentry.