Musk's space junk is a threat to us all

Pieces of space junk are falling to earth on a regular basis. On Techtonic this week I spoke with astronomer Samantha Lawler, who has been raising the alarm...

Creative Good
@markhurst @arstechnica @sundogplanets Gotta hand it to the billionaire "genius", their efforts endanger safety and security for all the planets inhabitants and for what? For their own profit.

@markhurst @arstechnica You probably already saw this, but there's a good analysis of threats to commercial aviation from reentries written by some of my colleagues here: https://www.nature.com/articles/s41598-024-84001-2

And it could have been a meteorite! One of my PhD qualifier exam questions was an order-of-magnitude estimate of how often a meteorite could take down a plane in flight, and I think about that a lot...

Airspace closures due to reentering space objects - Scientific Reports

Uncontrolled reentries of space objects create a collision risk with aircraft in flight. While the probability of a strike is low, the consequences could be catastrophic. Moreover, the risk is rising due to increases in both reentries and flights. In response, national authorities may choose to preemptively close airspace during reentry events; some have already done so. We determine the probability for a rocket body reentry within airspace over a range of air traffic densities. The highest-density regions, around major airports, have a 0.8% chance per year of being affected by an uncontrolled reentry. This rate rises to 26% for larger but still busy areas of airspace, such as that found in the northeastern United States, northern Europe, or around major cities in the Asia-Pacific region. For a given reentry, the collision risk in the underlying airspace increases with the air traffic density. However, the economic consequences of flight delays also increase should that airspace be closed. This situation puts national authorities in a dilemma—to close airspace or not—with safety and economic implications either way. The collision risk could be mitigated if controlled reentries into the ocean were required for all missions. However, over 2300 rocket bodies are already in orbit and will eventually reenter in an uncontrolled manner. Airspace authorities will face the challenge of uncontrolled reentries for decades to come.

Nature

@markhurst @arstechnica @sundogplanets I completely agree that all these assholes putting up thousands of satellites is a huge problem, and one reason is because all that stuff will eventually come back down.

But that said, there are vastly more meteors that enter our atmosphere than deorbiting human-made space junk, so in this particular case, it's far more likely the plane was struck by a space rock than by a chunk of satellite or launcher.

@michaelgemar @markhurst @arstechnica Show your work :)

Though I'd guess that the size distribution of meteorites vs. space reentry debris is VERY different, and that's pretty important for this estimate! But SpaceX and other commercial satellite companies haven't shared that data (and probably don't even collect that data, because they don't have to) so yeah.

@sundogplanets @markhurst @arstechnica The estimate I have seen is over 17,000 meteorites per year (and that's stuff that actually hits the ground).

https://pubs.geoscienceworld.org/gsa/geology/article/48/7/683/584575/The-spatial-flux-of-Earth-s-meteorite-falls-found

The spatial flux of Earth’s meteorite falls found via Antarctic data | Geology | GeoScienceWorld

@michaelgemar @markhurst @arstechnica Thanks for the reference! I don't know off the top of my head how to turn that meteorite size distribution plot into an aircraft risk plot, but probably someone has already done that...

(at least part of it is in this paper, with a focus on rocket bodies because they're real big: https://www.nature.com/articles/s41598-024-84001-2)

Airspace closures due to reentering space objects - Scientific Reports

Uncontrolled reentries of space objects create a collision risk with aircraft in flight. While the probability of a strike is low, the consequences could be catastrophic. Moreover, the risk is rising due to increases in both reentries and flights. In response, national authorities may choose to preemptively close airspace during reentry events; some have already done so. We determine the probability for a rocket body reentry within airspace over a range of air traffic densities. The highest-density regions, around major airports, have a 0.8% chance per year of being affected by an uncontrolled reentry. This rate rises to 26% for larger but still busy areas of airspace, such as that found in the northeastern United States, northern Europe, or around major cities in the Asia-Pacific region. For a given reentry, the collision risk in the underlying airspace increases with the air traffic density. However, the economic consequences of flight delays also increase should that airspace be closed. This situation puts national authorities in a dilemma—to close airspace or not—with safety and economic implications either way. The collision risk could be mitigated if controlled reentries into the ocean were required for all missions. However, over 2300 rocket bodies are already in orbit and will eventually reenter in an uncontrolled manner. Airspace authorities will face the challenge of uncontrolled reentries for decades to come.

Nature
@sundogplanets @markhurst @arstechnica That estimate is also what reaches the ground -- I don't know how many items would burn up between say 10,000m and the ground (although that would be true for both artificial and natural objects).
@markhurst @arstechnica @sundogplanets Yikes, this makes me kind of glad I retired from flying jets not long ago. We often went up to 45,000 feet and I hate to think of what slamming into space junk at near-supersonic speed would have been like up there.

@markhurst @arstechnica @sundogplanets

What I take away from this is that while Boeing struggles to design their doors so that they remain attached during flight, they do apparently build pretty good windshields.

@markhurst @arstechnica @cjmoorehead 8000 tons sounds like a lot, but 50 tons of natural meteorites hit the planet each DAY, and many are made of heavier metals like Iron & Nickel. That’s 200 BILLION tons of metals over 4.5B years. And we don’t appear to have suffered.

Mentioning this to Sam is likely to get you blocked, FYI.

@markhurst @arstechnica @sundogplanets

Matter of Russian roulette… can wait for it in fact…

@markhurst @arstechnica @sundogplanets look I dislike Musk and space junk just as much as the next person but the Ars article literally states that it is more likely to have been a meteor, although we don't have any details yet.

@sneako @markhurst @arstechnica @sundogplanets The most recent update I saw last night indicated it was a weather balloon.

The balloon launch company confirmed their balloon was in the vicinity at the time of the collision.

@markhurst @arstechnica @sundogplanets clearly killing people on the roads is just not enough for musk, he wants to be a threat to all modes of travel...🤣