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These numbers are not what I expected at all. So you could actually make an argument that to a country like the US, full 100% reliable asteroid protection is o

These numbers are not what I expected at all. So you could actually make an argument that to a country like the US, full 100% reliable asteroid protection is only worth like $50M/year (even if an impact means full extinction)? So if upkeep for a detection/deflection system costs more than that we'd be "better off" just risking it?! Thats insane. I would have expected this number to be much higher than $50M/year.

andruby 1y ago
The economists calculated the value of 1 life. The calculation might be different if it extinguishes the whole of humanity (and thousands of other species). In a way, it also presents all future human lives. Should we include those?
- myrmidon 1y ago
  I don't believe that this would change the outcome much: It seems hard to argue that preservation of a nonhuman species would be worth more than a million lives (=> negligible) and assuming global loss of all human life is already unreasonably pessimistic in my view-- (e.g. the Chicxulub impactor would not have achieved this). I also think that fully accounting for multi-generational consequences is murky/questionable and not really something we do even in much more obvious cases: Eligible people deciding against having children are not punished for depriving future society of centuries of expected workyears, and neither are mothers/fathers rewarded for the reverse. But even if you accounted for losing 3 full generations and some change (for biodiversity loss), that still leaves you in the ~$200M/year range. Currently we don't have reliable asteroid deflection capability at any price (but it would be technically somewhat in reach), but just imagine a future NASA budget discussion that goes "we're gonna have to mothball our asteroid deflector 3000 because it eats 5% of yearly NASA budget and thats just not worth it"-- that could be the mathematically correct choice, which confounds me.
  - cogman10 1y ago
    I think where the calculations are breaking down is in the probability of asteroid strikes. All the math assumes that the probabilities will follow historic trends and is relatively static. With single digit events, we really have no way in knowing what the actual likelihood of impact is. It could be 1 in 100 million, it could actually be 1 in 1 million and we've been rolling a bunch of nat 20s. Before we build out the asteroid blaster 9000, the first step is detection. With that in place then we get actual good risk and probability calculations. If the detector tells us "There's no object that will strike earth in the next 1000 years" we can safely not put any budget into asteroid defense. If, on the other hand, the detector shows "Chicxulub 2.0 will hit in the next 100 years" then your probability of an impact is 1 and the actual budget worth it is going to be much closer to that $8e+16 number calculated earlier.
    - myrmidon 1y ago
      I agree that detection is a very helpful first step and almost enough on its own. But I'm unsure how far this can be pushed-- I think impact certainty for a century or more might be physically impossible, because of uncertainty in orbital parameters and chaotic behavior of the whole system. I also believe the approximate bounds we have on impact probability are good enough for this estimate and quite unlikely to be off by a factor of 100, because we can guess at both size distribution and impact likelihood from craters (on earth and moon), and if the >10km object impact likelihood was over 1/million years we would expect to see a hundred times more craters of the corresponding size...
      - cogman10 1y ago
        > I think impact certainty for a century or more might be physically impossible, because of uncertainty in orbital parameters and chaotic behavior of the whole system. We already have 10s of years of certainty with the current observations. Most of the uncertainty comes from the interactions of unknown objects. As the mappings of objects increase, our predictions will become much better. The other thing to consider is that large objects will have much better certainty. A 10km asteroid won't be influenced (much) by colliding with 100 1m asteroids. It will only be impacted if it hits or swings by something like a 1km asteroid. Rubin should in a pretty short timeframe (a few years) give us an orbital mapping of all the >1km asteroids, which is pretty exciting.
adgjlsfhk1 1y ago
one thing this analysis is missing is the smaller asteroids. for every planet altering asteroid, there are hundreds that could cause a tsunami that would wipe out a few cities
- myrmidon 1y ago
  Good point, but I think those are "worth" less from a risk-analysis PoV: 1km diameter is apparently about 200 times more likely (1/500000 years) according to wiki, but would need to kill 40M people to match the extinction-level asteroid risk (so basically-- unmitigated hit on Tokyo or bust). To be honest, I think the 1km diameter range might still be a major fraction of the actual risk, because the estimates around "human exctinction every 100Ma" are probably much too pessimistic.
  - ianburrell 1y ago
    There is also a difference between mass extinction asteroid like dinosaurs, and one that destroys human civilization. Smaller one wouldn't extinct humanity but would kill most of the people alive. 1km might be big enough to do that depending on the amount of dust and cooling.
  - adgjlsfhk1 1y ago
    they may be worth less, but each class of them bumps up the value of detection since detection helps against all of them.

andruby 1y ago

The economists calculated the value of 1 life. The calculation might be different if it extinguishes the whole of humanity (and thousands of other species). In a way, it also presents all future human lives. Should we include those?

myrmidon 1y ago
I don't believe that this would change the outcome much: It seems hard to argue that preservation of a nonhuman species would be worth more than a million lives (=> negligible) and assuming global loss of all human life is already unreasonably pessimistic in my view-- (e.g. the Chicxulub impactor would not have achieved this). I also think that fully accounting for multi-generational consequences is murky/questionable and not really something we do even in much more obvious cases: Eligible people deciding against having children are not punished for depriving future society of centuries of expected workyears, and neither are mothers/fathers rewarded for the reverse. But even if you accounted for losing 3 full generations and some change (for biodiversity loss), that still leaves you in the ~$200M/year range. Currently we don't have reliable asteroid deflection capability at any price (but it would be technically somewhat in reach), but just imagine a future NASA budget discussion that goes "we're gonna have to mothball our asteroid deflector 3000 because it eats 5% of yearly NASA budget and thats just not worth it"-- that could be the mathematically correct choice, which confounds me.
- cogman10 1y ago
  I think where the calculations are breaking down is in the probability of asteroid strikes. All the math assumes that the probabilities will follow historic trends and is relatively static. With single digit events, we really have no way in knowing what the actual likelihood of impact is. It could be 1 in 100 million, it could actually be 1 in 1 million and we've been rolling a bunch of nat 20s. Before we build out the asteroid blaster 9000, the first step is detection. With that in place then we get actual good risk and probability calculations. If the detector tells us "There's no object that will strike earth in the next 1000 years" we can safely not put any budget into asteroid defense. If, on the other hand, the detector shows "Chicxulub 2.0 will hit in the next 100 years" then your probability of an impact is 1 and the actual budget worth it is going to be much closer to that $8e+16 number calculated earlier.
  - myrmidon 1y ago
    I agree that detection is a very helpful first step and almost enough on its own. But I'm unsure how far this can be pushed-- I think impact certainty for a century or more might be physically impossible, because of uncertainty in orbital parameters and chaotic behavior of the whole system. I also believe the approximate bounds we have on impact probability are good enough for this estimate and quite unlikely to be off by a factor of 100, because we can guess at both size distribution and impact likelihood from craters (on earth and moon), and if the >10km object impact likelihood was over 1/million years we would expect to see a hundred times more craters of the corresponding size...
    - cogman10 1y ago
      > I think impact certainty for a century or more might be physically impossible, because of uncertainty in orbital parameters and chaotic behavior of the whole system. We already have 10s of years of certainty with the current observations. Most of the uncertainty comes from the interactions of unknown objects. As the mappings of objects increase, our predictions will become much better. The other thing to consider is that large objects will have much better certainty. A 10km asteroid won't be influenced (much) by colliding with 100 1m asteroids. It will only be impacted if it hits or swings by something like a 1km asteroid. Rubin should in a pretty short timeframe (a few years) give us an orbital mapping of all the >1km asteroids, which is pretty exciting.

adgjlsfhk1 1y ago

one thing this analysis is missing is the smaller asteroids. for every planet altering asteroid, there are hundreds that could cause a tsunami that would wipe out a few cities

myrmidon 1y ago
Good point, but I think those are "worth" less from a risk-analysis PoV: 1km diameter is apparently about 200 times more likely (1/500000 years) according to wiki, but would need to kill 40M people to match the extinction-level asteroid risk (so basically-- unmitigated hit on Tokyo or bust). To be honest, I think the 1km diameter range might still be a major fraction of the actual risk, because the estimates around "human exctinction every 100Ma" are probably much too pessimistic.
- ianburrell 1y ago
  There is also a difference between mass extinction asteroid like dinosaurs, and one that destroys human civilization. Smaller one wouldn't extinct humanity but would kill most of the people alive. 1km might be big enough to do that depending on the amount of dust and cooling.
- adgjlsfhk1 1y ago
  they may be worth less, but each class of them bumps up the value of detection since detection helps against all of them.