5 ms·

We should. I've seen an analysis which concluded that your chances of dying in a meteor impact are about the same as your chances of dying in a car crash -- eg.

by nkoren 5y ago

We should. I've seen an analysis which concluded that your chances of dying in a meteor impact are about the same as your chances of dying in a car crash -- eg., really quite high. This doesn't sound right, because at as an individual, you're obviously far more likely to die in a car crash -- it's extremely unlikely that you'll personally die from a meteor impact. However in the very rare event that you are killed by an impact, then there's a very high probability that anywhere from tens of thousands to tens of millions will also be killed by the same event. So overall the numbers roughly balance out, and are high enough to be worth taking seriously. Fortunately there are groups that are doing just that: https://b612foundation.org/ https://b612foundation.org/

vkou 5y ago
The main problem here is that detecting a city-killer meteor before it hits you is incredibly difficult, which really puts a damper on your ROI. Meteors large enough to detect are both incredibly rare, and are very difficult to deal with, and meteors too small to detect will hit you before you see them. Not to mention that any detection will come with very large uncertainty bars. Suppose that you somehow discover that a ~500 KT meteor (Like the Chelyabinsk bolide - which was only ~20 meters across - good luck figuring out an accurate orbit for it) is an impact risk. The overwhelming majority of the Earth is covered with water. The overwhelming majority of the rest is... Not densely populated. And observations put it at a 0.5% chance of striking the Earth next year, with zero ability to predict which part of the Earth will be struck. That's the most likely outcome of a detection program. Not '100% chance', not '90% chance', but a '0.5% chance of a rock that's scary only if you're in its immediate path'. Is that worth doing anything about?
- ClumsyPilot 5y ago
  What's the cost of a nuclear missile (or X chosen method?) Whats the cost of NYC turning in a smoldering crater * 0.5% (or whatever)? The cost of all rockets ever launched is a pittance compared to NYC real estate Also there is a project for a space telescooe spesifically designed to locate asteroids, its not that difficult or even expensive. https://en.m.wikipedia.org/wiki/Sentinel_Space_Telescope https://en.m.wikipedia.org/wiki/Sentinel_Space_Telescope
  - dr_zoidberg 5y ago
    Having nuclear missiles ready at all times, all over the world (near populated areas) is a risk on its own... In a politically stable world without conflicts, sure, but we haven't had that kind of world for centuries...
    - kadoban 5y ago
      That's true, but we already have that. There's nukes all over the place. Not in all countries, but many.
      - yesenadam 5y ago
        > Not in all countries, but many. In 9 out of 195 countries.
        kadoban 5y ago
        True (I think? Right ballpark anyway). But, how much of the population does that cover? Between China and India to start with, should be quite a lot. And then you have alliances, the US has nukes in Europe and submarines a bunch of places. And that's just all the publicly known ones.
        deleted 5y ago
        [deleted]
        dr_zoidberg 5y ago
        You're not wrong. Possibly the biggest issue would be how can you quickly launch one of these without triggering WW3. Another issue I'm thinking is that I don't know the state of the art of meteor/bolide trajectory estimation (it's apparently very poor), so you'd probably need to fire a bunch of these (or a very large one) along an (uncertain) path hoping for it to affect the impactor. So this is just more of the same problem: how do you fire a barrage of nuclear missiles over a region to stop an impactor in such a way that you're not mistaken for a madman starting nuclear war?
- VLM 5y ago
  The global reaction to COVID is highly relevant to this discussion. As with covid the secondary and tertiary effects will be vastly greater than the primary effects. There is a fascinating logistics and timing feature to this whole topic. Aside from global panic'd masses. There is a huge logistical difference between sudden and unplanned electrical grid shutdown and subsequent black start vs a pre-planned five minutes outage (assuming we can predict impact to five minutes). Another interesting electrical utility issue is the radiological damage from a melted-down nuclear power plant varies exponentially with time... There's a huge difference in expected damage between whacking the coolant pumps a month in advance vs a day in advance vs a minute of warning vs no warning at all just no coolant flow.
- jtwaleson 5y ago
  About the water part: Historically you are completely right, but with the crazy amount of global shipping in the 21st century, I think lots of sea impacts would be detected and/or sink a couple of ships. Take a look at vessel finder and you'll see that there are only a few areas where ships are really far apart.

by nkoren 5y ago

vkou 5y ago

The main problem here is that detecting a city-killer meteor before it hits you is incredibly difficult, which really puts a damper on your ROI. Meteors large enough to detect are both incredibly rare, and are very difficult to deal with, and meteors too small to detect will hit you before you see them. Not to mention that any detection will come with very large uncertainty bars. Suppose that you somehow discover that a ~500 KT meteor (Like the Chelyabinsk bolide - which was only ~20 meters across - good luck figuring out an accurate orbit for it) is an impact risk. The overwhelming majority of the Earth is covered with water. The overwhelming majority of the rest is... Not densely populated. And observations put it at a 0.5% chance of striking the Earth next year, with zero ability to predict which part of the Earth will be struck. That's the most likely outcome of a detection program. Not '100% chance', not '90% chance', but a '0.5% chance of a rock that's scary only if you're in its immediate path'. Is that worth doing anything about?

ClumsyPilot 5y ago
What's the cost of a nuclear missile (or X chosen method?) Whats the cost of NYC turning in a smoldering crater * 0.5% (or whatever)? The cost of all rockets ever launched is a pittance compared to NYC real estate Also there is a project for a space telescooe spesifically designed to locate asteroids, its not that difficult or even expensive. https://en.m.wikipedia.org/wiki/Sentinel_Space_Telescope https://en.m.wikipedia.org/wiki/Sentinel_Space_Telescope
- dr_zoidberg 5y ago
  Having nuclear missiles ready at all times, all over the world (near populated areas) is a risk on its own... In a politically stable world without conflicts, sure, but we haven't had that kind of world for centuries...
  - kadoban 5y ago
    That's true, but we already have that. There's nukes all over the place. Not in all countries, but many.
    - yesenadam 5y ago
      > Not in all countries, but many. In 9 out of 195 countries.
      - kadoban 5y ago
        True (I think? Right ballpark anyway). But, how much of the population does that cover? Between China and India to start with, should be quite a lot. And then you have alliances, the US has nukes in Europe and submarines a bunch of places. And that's just all the publicly known ones.
        deleted 5y ago
        [deleted]
        dr_zoidberg 5y ago
        You're not wrong. Possibly the biggest issue would be how can you quickly launch one of these without triggering WW3. Another issue I'm thinking is that I don't know the state of the art of meteor/bolide trajectory estimation (it's apparently very poor), so you'd probably need to fire a bunch of these (or a very large one) along an (uncertain) path hoping for it to affect the impactor. So this is just more of the same problem: how do you fire a barrage of nuclear missiles over a region to stop an impactor in such a way that you're not mistaken for a madman starting nuclear war?
VLM 5y ago
The global reaction to COVID is highly relevant to this discussion. As with covid the secondary and tertiary effects will be vastly greater than the primary effects. There is a fascinating logistics and timing feature to this whole topic. Aside from global panic'd masses. There is a huge logistical difference between sudden and unplanned electrical grid shutdown and subsequent black start vs a pre-planned five minutes outage (assuming we can predict impact to five minutes). Another interesting electrical utility issue is the radiological damage from a melted-down nuclear power plant varies exponentially with time... There's a huge difference in expected damage between whacking the coolant pumps a month in advance vs a day in advance vs a minute of warning vs no warning at all just no coolant flow.
jtwaleson 5y ago
About the water part: Historically you are completely right, but with the crazy amount of global shipping in the 21st century, I think lots of sea impacts would be detected and/or sink a couple of ships. Take a look at vessel finder and you'll see that there are only a few areas where ships are really far apart.