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CrustalTrudger t1_j9p1yh9 wrote

Reply to comment by morningcoffee1 in What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl

As highlighted in most the papers I linked to (1) in comparing it to natural flux you have to consider not just the total mass but also the composition, i.e., for the natural flux of meteorites only about 5% are metal rich whereas most are silicates and (2) within the metal meteorite comparison to satellite comparison, we're talking primarily iron/nickel (for metallic meteorites) vs aluminum compounds (for satellites). The concentration and chemistry both matter for potential effects.

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compounding t1_j9qkeu5 wrote

Composition does matter, but silicate minerals have tons of aluminum in them.

A quick check shows that most types of low-iron meteorites appear to still be very roughly 5-10% aluminum by mass.

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VIRSINEPOLARIS t1_j9r9o3u wrote

>[...]silicate minerals have tons of aluminum in them.

That might be on Earth, because the lightness of aluminium drove its concentration in the crust.

> A quick check shows that most types of low-iron meteorites appear to still be very roughly 5-10% aluminum by mass.

According to https://periodictable.com/Properties/A/MeteoriteAbundance.html aluminium is ony 0.9 % of general meteorites mass.

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