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The looming threat of NEOs
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Except that most of those Urban centers are near oceans. Oceans that make up 75% of the Earth's surface. A strike in the Atlantic Ocean would wipe out the eastern seaboard of North America, and much of Europe. A Pacific Ocean strike would do lots of damage to Southeast Asia and the west cost of North American. An Indian Ocean strike would have a death toll not worth thinking about.
I don't need a direct strike to do massive property damage and in fact a direct strike would do less property damage.
B: Any amount of fallout is acceptable when weighed against global extinction, until at least, you reach the level where it will cause global extinction itself.
You wouldn't see much fallout, most of it would remain in space and almost all of the rest wouldn't survive entering the atmosphere.
Though if they had a week, they could theoretically time the launches right so that the ICBMs hit at thier maximum range, which I assume is in the neighborhood of a little ways beyond the Thermosphere (600-km).
So basically, trying to blow an asteroid out of the sky might work, assuming it's the classic giant hunk o' rock people think they are. But if it's this hollow kind, you're just wasting explosives.
The bolded part is patently false, which makes me think the rest of it is BS.
Kinetic energy is (mv^2)/2. A hollow asteroid of a given composition will have less mass than a normal asteroid of the same composition, so if the two asteroids have the same speed the hollow one will have less kinetic energy and thus do less damage.
Well, yeah, mathematically less force, but at the weights we're talking about with supposed "global killer" asteroids, it's the difference between fucked and royally fucked.
The main thing about the segment was to show that despite being hollow, shooting a rocket at it wouldn't result in it being shattered. Nothing would happen. And not hollow as in it's just a floating Kinder Egg in space, but more porous, like a sponge.
But either way, I've tried to find info to back this up, but I'm coming up empty. So whatever. It was during a month where Discovery channel seemed to have a "We're fucked" show every week. Showing documentaries on all these things that'll kill a country, if not the world. Stuff like:
-As per the thread, giant meteor hits Earth, and we can't do anything but imitate the dinosaurs by looking up. Conclusion: We're fucked.
-A mountain collapses in Africa, sending a huge chunk into the ocean, resulting in a super tsunami aimed at the eastern American coast, with next to zero time to attempt evacuation. Conclusion: We're fucked.
-The tectonic plates shift in such a way as to result in a super earthquake, destroying cities. Conclusion: We're fucked.
-Supposedly there's a giant magma pocket under Yellowknife that, if erupted, would create a super volcano that would erupt for days. Beyond the obvious close range damage, the massive amount of smoke spewed would blanket the world for years. Conclusion: We're fucked.
-Super storms. Everything from supercharged hurricanes, to electrical storms big and powerful enough to knock out entire city power grids, which result in society crumbling. Conclusion: We're fucked.
I swear, between episodes of Mythbusters and American Chopper, they seemed to air a special that was nothing more than what natural occurring disaster will fuck over the world. Which do nothing but depress the fuck out of you for the rest of the day.
Unless you pay attention and realize the idea isn't to launch a nuke up there and blow it a few feet away. The idea is to make a nuclear rocket by attaching to the rock, and focusing the blast away from the rock to nudge it to a better path.
Of course, if you can identify the problem far enough into the future, even the small acceleration caused by detonating a nuke on the asteroid's surface could be enough. That's the reason early detection is so important—not only does it give us time to design a mission, but the mission itself is easier.
Get out of here.
Only by digging tunnels in the planet in careful, planned out ways. Also, having a friends where one is insane and can teleport and a flying lizard that has craazy venom helps.
-- (Terry Pratchett, alt.fan.pratchett)
nuclear fallout? why would it not survive entering the atmosphere?
Exactly. In terms of "nudging" it way in advance though you run up against the fact that multi-body gravitational problems are chaotic, so I doubt you would be able to know far enough in advance that you were going to be hit. If the asteroid is in a non-chaotic regime, then a tiny nudge won't do anything - it will lapse right back into the same orbit.
I know this would be one of the wild and weird conspiracy theories or whatever. I do not believe that a meteor killed the dinosaurs because of certain things that live on still today since that time.
Certain plants, sea creatures, insects, bats and so on.
I thought Yellowstone has the trapped pocket of brine that is under 6000 feet of superheated rock?
In theory that superheated mud would flow making a huge mess of everything?
Along with tons of ash.
When the Yellowstone fires happened years ago I found it odd that it was raining ash in Cheyenne a few days after the fire started
I thought Yellowknife was a city in Canada near a the Great Slave Lake and a mine complex?
If we spend a few million a year we will gain large numbers of highly useful observatories, and be able to track all the most dangerous NEOs. Should we find that one will hit us within say, 60 years, then it would be a trivial task to divert it. One that even a small team of scientists with a very limited budget could achieve.
If conversely, we rely on our relatively pathetic last minute warning if that system we have now, and we find one heading for the earth which will impact in 5 years it will take the entire resources of the planet and require millions if not billions to die or starvation since all the worlds resources will need to go into redirecting the comet.
So, its certain doom vs a few million spent on something which is a good idea anyway. Just because the certain doom scenario seems vaguely unlikely is not a good reason to choose it.
Whoops, my bad. I did mean Yellowstone. Old Faithful. That's the one that if it erupts just right results in a 4 day long erupting volcano that blackens the world.
Sorry 'bout that.
For a linear trajectory, sure. For a periodic system, no. Such systems automatically correct small deviations because they are stable, like a ball in a quadratic well. Give them a small push one way, and they quickly settle back in their former state (negative Lyapunov constant).
Gravitational systems can become unstable if you have non-negligible multi-body effects. This is why there can be two stars in a mutual orbit, but never three. In this case the system is chaotic, and it becomes impossible to predict long-term behavior, so we would have no idea whether objects in this regime were going to strilke Earth or not.
The heat of re-entry would vaporize it, but you wouldn't intercept in the upper atmosphere. Because the further out you can tag it, the less force you need.
How is vaporized nuclear material safer?
Dilution is the solution to pollution.
IE, 500g of plutonium dispersed evenly throughout the atmosphere of the earth is trivial, 500g of plutonium sitting next to you in your house is not.
Yes, but again, how could you ever know that these were going to hit Earth in time to do something about it?
still survives re-entry, and when talking about nuking the hell out of something near earth, it is going to be pretty well spread out.
I believe the particles are pretty small, unmassive, and are probably already oxides, so re-entering the atmosphere isn't going to do much. whatever conditions are, they are pretty mild compared to those the material went through a little while earlier.
if it is enough fallout to matter, it coming back through the atmosphere shouldn't make much diffrence, unless it all stays in the upper atmosphere or something. Maybe it would take a few centuries before it got down to earth? I'd buy that. I'd buy not enough getting to earth to matter too.
The whole not surviving thing. Well, that's not how fallout works.