In an EV thread, orbital debris is discussed. This re awakening might be more appropriate. It may seem paradoxical that increased CO2 in atmosphere could extend debris durations (lifetimes seems like the wrong word). It works like this: Troposphere heats, leaving less outgoing infrared. Then stratosphere cools (those parts are well studied). Stratosphere contracts, allowing the (further out) thermosphere to contract. At any given altitude thermosphere becomes less dense, so debris gets less frictional slowdown, and persists for longer. That increases probability of bumpercars. == All of that is counteracted by solar charged-particle fluxes. Notably when sun has lots of spots. Those have an opposite effect on thermosphere. Low earth orbit cleans itself a bit better of debris.
Concur. I'm still having a think about this. There's a lot of new 'panic porn' about this topic lately. Entertainment is where you find it..... 'Space Deathtrap': The terrifying way climate change could destroy low Earth orbit for good 'space deathtrap....' How DARE you!!!
" ...the asteroid that is going to hit us ..." A few months ago path calculations for 2024YR4 got above 3% IIRC. This was the highest % ever calculated for any of rocks out there. Additional observations were made causing the % to become known as much smaller Latest Calculations Conclude Asteroid 2024 YR4 Now Poses No Significant Threat to Earth in 2032 and Beyond – Planetary Defense
https://arstechnica.com/space/2025/11/landing-postponed-for-chinese-astronauts-after-suspected-space-debris-strike China's Tiangong orbital station has 3 on board who won't be re entering just yet. Their downgoer seems to have been hit by orbital debris and may not be fit for that purpose. I would have thought that another 3 would go up and replace then but apparently that was not the plan. Instead if the re-entry vehicle not used, another rocket will send one up uninhabited. There may be some irony in this. Space-launch nations have contributed unequally to the amount of orbital debris, and this nation has contributed quite a lot
Most orbital debris is not ferromagnetic Encountering schnutz with high relative velocity could disassemble a Wilson magnet, so this is not a great plan, sorry. Ars article linked above says that Taikonauts' 4 EVAs have been to add shielding against highly energetic little bits. Maybe it could not be launched with enough wrapping / shielding. Or risk from damage from such was underestimated? Talking here about not the most 'transparent' space agency. It is also well to note (again) that <1 cm orbital debris are not trackable from earth surface. By any disclosed way. == I reckon that 3 current Taikonauts will over stay their planned 6 months by not much, and that they have adequate oxygen, water, food stores on board to wait it out. I reckon that this inconvenience won't figure highly in media reporting - there is so much else to talk about!
One fairly effective method for small bits seems to be a layer of thin foil, or multiple such layers, with significant gaps between each and the vessel shell. The high speed bit and the piece of foil it hits first are all vaporized on contact, the plasma spreads out in a cone before it reaches the next layer, where it hits a much wider (and more mass) impact zone with less penetrating power, getting slowed and spread even more. By the time this hot gas cloud reaches the vehicle's pressure shell, it is much less able to puncture it. This sort of structure is too light and fragile to withstand the atmosphere and wind of a ground launch, so must be either behind a fairing, or deployed in orbit. Might the space agency be installing something such as this? A 1 cm impactor will blow through this structure and not vaporize much until hits something much heavier. Though a similar concept, of heavier layers and wider gaps, might do the job.
Actually, a number of asteroids have been calculated at 100%, first in 2008, then 2014, now numbering several per year. Impact warnings have all been under 24 hours, some as short as a couple hours. So far, all these have been of nice fireball size, nothing approaching the Chelyabinsk event, just gnats compared to 2024YR4. Here is a list of them: List of predicted asteroid impacts on Earth - Wikipedia These were detected late because they were so small. Larger ones can be detected from farther away. The intent of the search is to find and catalog as many of the dangerous ones as possible, as far in advance as possible. As the equipment improves, the detection rate of the small ones keeps increasing, while finds of new large ones keeps shrinking, statistically suggesting that most of the large ones have already been found. But plenty of mid-sized ones, still hazardous, remain un-discovered.
