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

  • Hadriscus@lemm.ee
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    6 months ago

    damn, starlink is my only way to access the internet. I wish there were an alternative that’s usable. Traditional access providers don’t work and cell data is extremely slow and there’s no coverage where I live. I pay for Starlink with a bitter taste

    • Dasus@lemmy.world
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      6 months ago

      Might I enquire as to where this remote location might be?

      Like on a general basis, no need for addresses.

      As a Finn I’m forever spoiled in terms of wireless coverage. We got tons of solitary forests. But you can get an internet connection in literally all of them.

      97% of the country gets 4g. And not of the people. The country.

      • enbyecho@lemmy.world
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        6 months ago

        I live in rural California. We only just this year are able to pick up a faint LTE signal. I think it might get us a very unstable 1-2 Mbps if we hold the phone just right. We have no cable, DSL or other land-based options and because of the topography can’t pick up the local wireless provider, which is very expensive anyway - like $175/month for 50/5

        So without Starlink our only options are crappy regular satellite providers like Hughesnet which impose very low quotas - 10 GB monthly for day time usage - and have insane latency.

        It bugs the shit out of me I have to give money to that fuckwit but without it we live in the dark ages.

      • Hadriscus@lemm.ee
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        6 months ago

        We’re in Mayotte. Two undersea cables connect us to nearby continents (cf submarinecablemap.com) but they’re down most of the time. We haven’t had a connection in the last six months so we finally subbed to Starlink. Well, strictly speaking there was a connection but it would take anywhere between 5mn to 15mn to load the text of a static webpage, no images or anything else… forget about sending data, using forums… I had to get out and walk uphill for a minute or two to use my phone’s cell data

      • jj4211@lemmy.world
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        6 months ago

        My family has Starlink, they live in mountainous rural. Cell towers aren’t too far away, but mountains get in the way of decent signal. No one is running any cables their way, despite a local telco taking money explicitly for providing internet service.

      • nyctre@lemmy.world
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        6 months ago

        Rural US most likely. Place is too big, too few people to be worth for comoanies to invest. So many places only have 1-2 providers at best, afaik.

      • TheGalacticVoid@lemm.ee
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        6 months ago

        What about the remaining 3%?

        Also, to (hopefully) answer your question:

        Ignore Finland/Europe for a second and look at North America. The US has many population centers along the coasts and very few in the west inland. People still live there, so they need internet access, but oftentimes there aren’t enough people to justify expanding coverage across such a huge area without subsidizing said coverage with government funds or other customers, so there are bound to be coverage gaps if you don’t have unlimited money to throw at the problem. If you take a look at Canada, you can see how much worse the problem is as they have even more area to cover, and it reflects in the fact that they have some of the highest wireless prices in the world.

        Also remember that these are wealthy countries. Plenty of other regions have the same problems with population density and physical size, and they can’t throw money at the problem like we can.

        The TL;DR is that these deadzones exist in a ton of places because a lot of low-population areas are physically huge.

        • Dasus@lemmy.world
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          6 months ago

          I remind you that it’s the remaining 3% of the country, physically. It’s not 3% of the population. It’s just some places in Lapland which don’t have the greatest coverage. And the 97% figure is 4g, 3g has better coverage.

          The Northern part of Finland is very sparsely populated and people like internet and cables are very labour-intensive compared to setting up mobile network towers.

          But yeah, compared to the US, we’re not really that sizable. We’re like the size of Montana or so, and they’ve around a fifth of our population.

          tldr Yeah, it is about the size, but also, with Nokia and so on, we’ve sort of quite a lot of good know-how on building wireless networks. We’re the most sparsely populated country in the EU, but I think there’s quite a lot of Spain where there’s much worse coverage.

      • Hadriscus@lemm.ee
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        6 months ago

        lol that’s fantastic. Out in the forest with internet. How come, cell towers are closely packed ?

      • Dkarma@lemmy.world
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        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.world
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          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.world
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            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.ca
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            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.world
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              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.world
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                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.world
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                  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.world
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                    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.world
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                  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.world
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              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.ca
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                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.world
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                  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.