this post was submitted on 16 Apr 2024
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[–] partial_accumen@lemmy.world 15 points 7 months ago (2 children)

"Meteors only contain trace amounts of highly conductive metals" Solter-Hunt said. "Satellites, on the other hand, are basically entirely made of superconductive metals."

7% of meteorites that strike Earth are either entirely metal or partially metal. Additionally, the metallic ones are usually larger than the stony ones. I'm sure a PHD knows this, so I'm guessing the author of the article didn't include some context.

source

[–] wjrii@lemmy.world 10 points 7 months ago* (last edited 7 months ago) (1 children)

The numbers are kind of all over the place, and the verbiage in quotes from the PhD herself are oddly imprecise. For instance, she doubles down on the incorrect use of "superconductor."

"Satellites are mostly made of aluminum and aluminum is a superconductor," Solter-Hunt said. "Superconductors are used for blocking, distorting or shielding of magnetic fields.

Then, there is the amount of mass that the Starlink sats could leave behind:

50 tons of space rocks evaporate in Earth's atmosphere every day, leaving behind about 450 kilograms of charged dust, according to Solter-Hunt's calculations. That is three times less than what a single re-entering Starlink satellite generates.

The link in that passage says that the newer, bigger Starlink satellites are only 800 kg in total mass. I'm not entirely sure how an 800kg object leaves 1300+ kg of "charged dust" upon re-entry. Maybe there's compounding factors due to the prorated amount of rocket parts also burning up or something, but this whole thing seems... off. This is not to say that space junk is not a major issue or that a Musk-owned company would voluntarily do the responsible thing, but I say we put a pin in this for now and see what happens with her paper and any related research.

[–] partial_accumen@lemmy.world 8 points 7 months ago (1 children)

“Satellites are mostly made of aluminum and aluminum is a superconductor,” Solter-Hunt said. "Superconductors are used for blocking, distorting or shielding of magnetic fields.

"Though 100 Kelvin is still pretty chilly -- that's about -280 degrees Fahrenheit -- this is an enormous increase compared to bulk aluminum metal, which turns superconductive only near 1 Kelvin (-457 degrees Fahrenheit)" source

It doesn't get that cold in LEO or GEO, so I'm not sure why the author of the paper is bringing that up. This paper and its author are looking more suspect by the minute.

[–] intrepid@lemmy.ca 2 points 7 months ago

I'm pretty sure that the environment inside the satellite gets nowhere near that cold. There are a lot of things like propellants and batteries which won't work if it gets cold. They usually have an active thermal control system to regulate temperature.

[–] explore_broaden@midwest.social 9 points 7 months ago

I looked at the paper they’re talking about (which has not yet been peer reviewed), and I couldn’t find any past peer reviewed research from the author. The paper also doesn’t really explain any of its arguments past referencing sometimes unrelated stuff that “sounds scientific,” so I suspect it will be rejected from any reasonable journal. Some of their graphs seem to have problems and their comparisons to the mass of the Van Allen belts seem questionable. Also radiation belts don’t really “protect earth”.

Writing a news article based on a Arxiv article from an author that isn’t established seems extremely dubious.