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I couldn’t see a quantitative estimate of how much ozone would be depleted in a typical year as a result of the extra catalyst being present. If it’s only ~hund

by jl6 2y ago

I couldn’t see a quantitative estimate of how much ozone would be depleted in a typical year as a result of the extra catalyst being present. If it’s only ~hundreds of tons, that seems both immaterial (there are about 3 billion tons of ozone in the atmosphere currently) and potentially easy to replace (fly up there and dump some fresh ozone).

gmm1990 2y ago
I think it says its a catalyst, for some chlorine reaction. So its not out of the question 300 tons (per year) could effect ozone concentrations.
- marcosdumay 2y ago
  There's absolutely no estimation of the impact. Your 300 tons of activated chlorine per year idea is as baseless as the GP's 300 tons of ozone, but the GP is aware that his number is a complete invention. Any exercise in making numbers out of nothing is completely useless. (Besides, is chlorine activation really a bottleneck in ozone depletion? AFAIK it gets activated by UV light quite quickly.)
  - gmm1990 2y ago
    GP never implied the amount of ozone just the amount of aluminum oxide. All I know is catalysts can speed up reactions by orders of magnitude. CFCs actually created a hole in the ozone layer so its not like human activities haven't accidentally created problems before. Probably something that at least needs to be ruled out.
    - deleted 2y ago
      [deleted]
    - oasisbob 2y ago
      Correct. That's the same way I read that comment. More fundamentally, chemical catalysts by definition are not consumed by the reactions they catalyze. Think: a cheese grater. It doesn't react with the cheese, so a few ounces of grater could make hundreds of pounds of grilled cheese. A hypothetical 300 tons of catalyst is not limited stoichiometrically to how much substrate it would affect.
ldoughty 2y ago
If starlink thinks it may have 40,000 satellites at full capacity[1] .. and we expect at least 1 if not 2 competitors.. With a 5-year lifespan for an LEO sat, that's potentially 120,000 deorbits every 5 years... That will add up quickly... I don't know the science of aluminum oxide increase to ozone depletion.. but this can certainly warrants more research and consideration 1: https://starwalk.space/en/news/spacex-starlink-satellites-night-sky-visibility-guide https://starwalk.space/en/news/spacex-starlink-satellites-ni...
- deleted 2y ago
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- deleted 2y ago
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- aftbit 2y ago
  https://www.antipope.org/charlie/blog-static/2024/05/on-mistaking-a-transient-state.html https://www.antipope.org/charlie/blog-static/2024/05/on-mist...
- AtlasBarfed 2y ago
  Can't they spray some ozone as they deorbit?
  - s1artibartfast 2y ago
    No, but I imagine they could include some other solid mass that has a counter effect.
    - brewdad 2y ago
      Chemtrails!
- mathsmath 2y ago
  The satellites are typically much smaller than historic satellites. I think ~50-60 are launched in a fairing that would house 1 or two older-style satellite. Does the mass make a difference?
BurningFrog 2y ago
Catalysts don't get consumed by the reactions they facilitate, so the weight of the catalyst compared to the ozone doesn't say much about the effect. For example, consider that a car exhaust catalyst contains ~5 grams of platinum, and AFAIK, that doesn't really "wear out".

by jl6 2y ago

gmm1990 2y ago

I think it says its a catalyst, for some chlorine reaction. So its not out of the question 300 tons (per year) could effect ozone concentrations.

marcosdumay 2y ago
There's absolutely no estimation of the impact. Your 300 tons of activated chlorine per year idea is as baseless as the GP's 300 tons of ozone, but the GP is aware that his number is a complete invention. Any exercise in making numbers out of nothing is completely useless. (Besides, is chlorine activation really a bottleneck in ozone depletion? AFAIK it gets activated by UV light quite quickly.)
- gmm1990 2y ago
  GP never implied the amount of ozone just the amount of aluminum oxide. All I know is catalysts can speed up reactions by orders of magnitude. CFCs actually created a hole in the ozone layer so its not like human activities haven't accidentally created problems before. Probably something that at least needs to be ruled out.
  - deleted 2y ago
    [deleted]
  - oasisbob 2y ago
    Correct. That's the same way I read that comment. More fundamentally, chemical catalysts by definition are not consumed by the reactions they catalyze. Think: a cheese grater. It doesn't react with the cheese, so a few ounces of grater could make hundreds of pounds of grilled cheese. A hypothetical 300 tons of catalyst is not limited stoichiometrically to how much substrate it would affect.

ldoughty 2y ago

If starlink thinks it may have 40,000 satellites at full capacity[1] .. and we expect at least 1 if not 2 competitors.. With a 5-year lifespan for an LEO sat, that's potentially 120,000 deorbits every 5 years... That will add up quickly... I don't know the science of aluminum oxide increase to ozone depletion.. but this can certainly warrants more research and consideration 1: https://starwalk.space/en/news/spacex-starlink-satellites-night-sky-visibility-guide https://starwalk.space/en/news/spacex-starlink-satellites-ni...

deleted 2y ago
[deleted]
deleted 2y ago
[deleted]
aftbit 2y ago
https://www.antipope.org/charlie/blog-static/2024/05/on-mistaking-a-transient-state.html https://www.antipope.org/charlie/blog-static/2024/05/on-mist...
AtlasBarfed 2y ago
Can't they spray some ozone as they deorbit?
- s1artibartfast 2y ago
  No, but I imagine they could include some other solid mass that has a counter effect.
  - brewdad 2y ago
    Chemtrails!
mathsmath 2y ago
The satellites are typically much smaller than historic satellites. I think ~50-60 are launched in a fairing that would house 1 or two older-style satellite. Does the mass make a difference?

BurningFrog 2y ago

Catalysts don't get consumed by the reactions they facilitate, so the weight of the catalyst compared to the ozone doesn't say much about the effect. For example, consider that a car exhaust catalyst contains ~5 grams of platinum, and AFAIK, that doesn't really "wear out".