SpaceX's growing Starlink megaconstellation could be hindering the Earth's ozone layer from healing itself, researchers find.

Abstract from the paper in the article:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109280

Large constellations of small satellites will significantly increase the number of objects orbiting the Earth. Satellites burn up at the end of service life during reentry, generating aluminum oxides as the main byproduct. These are known catalysts for chlorine activation that depletes ozone in the stratosphere. We present the first atomic-scale molecular dynamics simulation study to resolve the oxidation process of the satellite’s aluminum structure during mesospheric reentry, and investigate the ozone depletion potential from aluminum oxides. We find that the demise of a typical 250-kg satellite can generate around 30 kg of aluminum oxide nanoparticles, which may endure for decades in the atmosphere. Aluminum oxide compounds generated by the entire population of satellites reentering the atmosphere in 2022 are estimated at around 17 metric tons. Reentry scenarios involving mega-constellations point to over 360 metric tons of aluminum oxide compounds per year, which can lead to significant ozone depletion.

PS: wooden satellites can help mitigate this https://www.nature.com/articles/d41586-024-01456-z

  • Dkarma@lemmy.worldEnglish
    320·
    6 months ago

    I love it when ppl from small countries don’t get why there isn’t wifi / cell coverage literally everywhere…

    • Senshi@lemmy.worldEnglish
      51·
      6 months ago

      Finland is not a small country compared to its population density and distribution.

      Finland has 18 inhabitants per km².

      USA have 35 inhabitants per km².

      • Dasus@lemmy.worldEnglish
        3·
        6 months ago

        Huh. TIL.

        But these are sort of not that good indicators, because the US has huge population centers on the coasts, and nothing in the vast center.

      • ILikeBoobies@lemmy.caEnglish
        35·
        6 months ago

        That’s not a good measurement as populations are not spread evenly. You could have 10 000 people per km^2 in the US then have 0.001 people per km^2 in another

        • RunawayFixer@lemmy.worldEnglish
          10·
          6 months ago

          The Finn already addressed this in their first post: 97% of the country has 4g. That is country, not people in the country. So yes, a reindeer in Lapland has a better potential internet connection than many rural north americans.

          Edit: I found some recent numbers: this carrier claims to provide 4g to 99% of the population, 5g to 96%. https://www.dna.fi/wholesale/about-us/networks That 2nd statistic must be pretty damn rare, the country of Nokia indeed.

          • Dasus@lemmy.worldEnglish
            1·
            6 months ago

            Yeah since most people don’t live in the parts of the country no-one lives in, when looking at how many people are covered, it gets pretty good. And we didn’t take long to get 5g to a lot of people.

            Here’s a coverage map from Elisa. https://elisa.fi/kuuluvuus/

            • RunawayFixer@lemmy.worldEnglish
              1·
              6 months ago

              Tbh, that 4g coverage up north looks pretty damn good for how few people live there. To me it just makes no economic sense to provide that good a service there. So I’m curious and as a Finn you might know: does it make economic sense or was this investment done for other reasons?

              • Dasus@lemmy.worldEnglish
                2·
                6 months ago

                I wish I had a good answer, but I don’t, really.

                Probably a combination of just providing a service and having good technology to do so and companies which want to sell said technology, I guess?

                Everyone enjoys the internet. I might be assuming, but the sort of “if you want services, move to a city” sort of rhetoric that might exist somewhere in the US doesn’t really exist for us Finns. We understand wanting to live in the middle of the woods while still having access to basic services.

                The Northern part is very sparsely populated, yeah (well not compared to some other places in the middle of huge states in the US but) something like two people per square kilometer, but rural living is pretty common throughout the country, so the whole country understands the need for them, perhaps?

                Also, I think a lot of the towers are older towers for just 2g, going back from GSM to NMT, those towers always just being updated with newer technology, again perhaps? (I’m too lazy to research this now.) And the need to have just cellular networks to be able to call emergency services if you’re lost deep in the woods has always been a pretty high priority, I think?

                The only places you maybe can’t get cell reception in Finland are some places in the middle of a few national parks in Lapland.

                • RunawayFixer@lemmy.worldEnglish
                  1·
                  6 months ago

                  Hey, thanks for taking the time to answer.

                  Afaik, high internet speed requires higher frequencies and high frequencies reach less far + have less penetration through/around obstacles. That’s what makes providing “4g” virtually everywhere easy (good enough for phone calls at least), but if they want to provide actual high speeds everywhere, then it suddenly becomes not so easy (nor cheap).

                  That the USA and Canada don’t provide proper high speed internet access/choice to many of their rural citizens is caused by the rent-seeking mentality of their network companies + the governments that enable this. Most of those rural citizens live in places where there are more than enough people for it to make economic sense to invest, but investing would lower short term profits, so they don’t. Instead those customers are stuck with the choice between a single provider who is offering bad service, or no service at all. And as we’ve seen with the Boobies American, they’ve got enough of their dumb citizens convinced that they are oh so exceptional that this is the best that they could ever expect.

                  • Dasus@lemmy.worldEnglish
                    1·
                    6 months ago

                    Afaik, high internet speed requires higher frequencies and high frequencies reach less far + have less penetration through/around obstacles. That’s what makes providing “4g” virtually everywhere easy (good enough for phone calls at least), but if they want to provide actual high speeds everywhere, then it suddenly becomes not so easy (nor cheap).

                    Why are you putting “4g” in quotes? It is 4g. Basic cellular networks cover the entire country, and using 4g speeds has been common for a long time. Hell, back when I was in the army, I had a laptop with a mobile connection. It was 3g back then, but it worked, even from the deepest of woods we were in.

                    The terrain of Finland probably makes this easier for us, as this is a rather flat country. We have literally no mountains. A few fells (=large hill, essentially) , but no mountains.

            • RunawayFixer@lemmy.worldEnglish
              4·
              6 months ago

              And why are you unwilling to accept that there is a lot of nothing land in Finland? Most of Finland is a lot of nothing land, plagued by mosquitoes in the summer and darkness in the winter.

              Your country is neither unique, nor exceptional in this regard.

        • Senshi@lemmy.worldEnglish
          2·
          6 months ago

          You are absolutely correct that distribution matters. However, Finland has an even more uneven population distribution than the US. 75% of the population lives in the costal cities, with 30% of the entire population living in the capital region( density of 193 persons/km²). The entire rest of the country is not empty dessert ( which would require no services), but very sparsely populated rural woodlands, down to 2 people per km².

          Density still is an overall useful quantifier given that extra knowledge, as providing services for a small population of only 5.6mio inhabitants is not easy either. Sure, providing coverage for the 75% in the cities is fairly easy. But that still leaves 1.5mio rural residents, which require huge investments in cable to supply with broadband. And due to the vast distances, you definitely cannot cover them with wireless alone, if you were thinking that.

          • ILikeBoobies@lemmy.caEnglish
            1·
            6 months ago

            Compare the diameter of the two countries

            If you only look at one line between LA and NYC, that is a lot more cable being laid. Now add something remote like the middle of Alaska vs the middle of Finland. We can assume for this example that they both service 100 people but the cost to do so for the US is a lot higher

            That’s why using density makes no sense

            • Senshi@lemmy.worldEnglish
              3·
              6 months ago

              Laying even 10 times the cable should not be more difficult when you have 60 times the total population (335mio in US vs 5.6mio in Finland) and hence more resources.

              And sure, Alaska definitely it’s expensive and inefficient to service, having a pop density of about 0.5 inhabitants per km². But unlike Northern Finland, most of Northern Alaska is in fact entirely void of human life and more akin to a desert. There really mostly are a handful of oil industry clusters and native communities. And still, the extremely low pop density means it’s only 730 000 people living in Alaska. That is 0.2% of the entire population of the USA. If you were to completely ignore and not service Alaska, you should have a an even easier time providing service to the vast majority of the US population in all the main states. I think it’s pretty clear this is a political failure and not a matter of financial resources or natural obstacles.