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Comment by feral | Hacker News Reader

Not a specialist, but I don't buy this.

In this story, they have a 6-year warning of an asteroid with 35% chance of 700megaton impact.

I just know that with that lead time, and with such an aligning mission, humanity would be able to do amazing things.

The Apollo program was from JFKs speech in '61 to moon in '69, and that's built on a '60s technological and social infrastructure. We have tons more brainpower and tech now, globally.

This scenario would just be so politically aligning we'd be able to mobilize massive resources to stop it in that timeframe; way more than 6 launches. I'd be much more concerned about one they didn't see until 6 months out or something.

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> This scenario would just be so politically aligning we'd be able to mobilize massive resources to stop it in that timeframe; way more than 6 launches. I'd be much more concerned about one they didn't see until 6 months out or something.

So what you're saying is, this optimistic scenario where everyone pitches in to do the rational-but-expensive thing to save themselves is less like an imminent car crash that's unavoidably about to occur because an oncoming car has swerved into our lane, and more like... the steps we'd need to take to avoid drastic climate change?

That's the scenario where you don't believe we'd fail to do the right thing?

I had a similar thought. Leaving aside the merits on the short story and how realistic it is, I think the major distinction with climate change is that there is not a large group of wealthy and influential people profiting from the existence of the asteroid.

I disagree with your analogy, on the grounds of human factors.

If we were talking about budgeting money to detect an asteroid in the first place, the analogy would be spot on. And indeed, we do suck at detection, its a tragedy of the commons, its difficult to align on, all those things you mention. Because its abstract.

But, IMO, there is a huge psychological difference between trying to sell the public on detecting an asteroid, vs diverting one we know is coming. The one you know is coming is this concrete physical threat.

This is very easy to sell. At a visceral level, almost everyone has been hit by a rock. Once you believe NASA telling you its coming - and I bet policy makers will believe that piece - the rest sells itself.

This is the difference between getting someone to pay money for health insurance, vs getting them to pay to remove a tumor. The former is a much harder conversation than the latter, though they are functionally the same.

Climate change involves explaining the impact of potential changes to a complex system.

There have been very many action movies about asteroid deflection. Its simple, its dramatic, its sudden. Its like the moon landing. Climate change is this slow creeping abstract thing, and that honestly matters hugely in terms of human factors.

It's better compared to the effort made in a war, to fight nazis, etc. There wasn't much talk of cost - cutting once your country might be obliterated. And unlike nazis, asteroids don;t negotiate

Half the politicians will be telling people that the asteroid is nothing to worry about. That it's a wild goose chase cooked up by the other side, and that we should be spending our tax money on more important things.

I like your optimism. But I see most people just shrugging their shoulders if they don't see how it could affect them. Long term risk often hard for humans to comprehend.

At six years out, it’s unclear where the asteroid will strike. You think Americans will throw their national budget behind doing “amazing things” for the Caribbean?

How localized would the effects of a 700 megaton impact be?

You can get a decent idea of the effects up to 100MT here

https://nuclearsecrecy.com/nukemap/

Excellent calculator & visualization

Horrible mental exercise...

As localized as a 700 megaton nuke (compared to the 13-18 kiloton nuke that his Hiroshima). Reliable sources say that virtually everything within a 3 mile radius from the impact was heavily damaged in Hiroshima and everything within 1.6km / ~1 mile radius was obliterated so you should be able to extrapolate from that.

For comparison, the entire USA is ~3.797 million sq miles, so the equiv area of 184.35 entire United States would be utterly obliterated.

    700000000 - 18000 = 699,982,000 sq miles of totally obliterated things

For comparison, the entirety of planet earth is 196.9 million sq miles, so the equiv area of 10 planet earths would be heavily damaged.

    (700000000 - 18000) * 3 = 2,099,946,000 sq miles of heavily damaged things

Update: My math is totally wrong and people smarter than me explained it. Yay for internet people!

I'm a bit skeptical of your math. 700 megatons would be a bit over 10x the size of the biggest nuke ever detonated, which was still a city-killer, not a country-killer.

Yield isn't linear. It's a cube root relationship.

The difference between 100MT, 10MT and 1MT is hardly insignificant, but it's smaller than many people realise.

FWIW a ballpark estimate says 700MT would have a 1 psi overpressure radius - which would break windows but not buildings - of less than 100km.

It would be a huge bang and the noise would circle the world a few times. But if it landed on land, the total obliteration region would be smaller than a state. And the explosion itself wouldn't be extinction-level - although the winter that followed it would cause some severe problems.

Tambora, which is the biggest explosion in modern records, was estimated around 33GT, and the blast effects from that were very, very, very bad, but still relatively localised.

Chicxulub has been estimated as at least 20 billion Hiroshimas - and perhaps as much as four times that. That set fire to most of a hemisphere. And it still wasn't a complete obliteration/sterilisation event.

> Chicxulub has been estimated as at least 20 billion Hiroshimas - and perhaps as much as four times that. That set fire to most of a hemisphere. And it still wasn't a complete obliteration/sterilisation event.

Unless you were a dinosaur living at the time :)

Thanks for the cluebat, I've put an update on my post to note the math is all bollocks.

Depends where it hits. An ocean hit would wipe out coastal communities all around the ocean. A land hit would send up huge amounts of dust and plunge the world into a nuclear winter for some time. A hit in the right kind of coastal shelf could replicate the K-T impactor.

200 megaton https://en.wikipedia.org/wiki/1883_eruption_of_Krakatoa

Such a huge asteroid may be exactly what we need to slow down global warming - fighting one catastrophe with another:

"In the year following the 1883 Krakatoa eruption, average Northern Hemisphere summer temperatures fell by as much as 1.2 °C (2.2 °F).[12] Weather patterns continued to be chaotic for years, and temperatures did not return to normal until 1888.[12] The record rainfall that hit Southern California during the water year from July 1883 to June 1884 – Los Angeles received 38.18 inches (969.8 mm) and San Diego 25.97 inches (659.6 mm)[13] – has been attributed to the Krakatoa eruption.[14] There was no El Niño during that period as is normal when heavy rain occurs in Southern California,[15] but many scientists doubt that there was a causal relationship.[16]

The Krakatoa eruption injected an unusually large amount of sulfur dioxide (SO2) gas high into the stratosphere, which was subsequently transported by high-level winds all over the planet. This led to a global increase in sulfuric acid (H2SO4) concentration in high-level cirrus clouds. The resulting increase in cloud reflectivity (or albedo) reflected more incoming light from the sun than usual, and cooled the entire planet until the suspended sulfur fell to the ground as acid precipitation."

If your government is willing to spend trillions on adventures in syria and other countries, and they have no real impact on the life of an average american, they they will scrape together a few billion to save their collective asses.

That seems likely, considering the US provides the most foreign and humanitarian aid.

http://devinit.org/post/global-humanitarian-assistance-repor...

"...the US remained the single largest donor, providing almost a third (32%) of all assistance"

We also have much cheaper and more reliable access to space. SpaceX and eventually Blue Origin will continue to push this down significantly. The one downside of this is that the same types of tools in space to deflect asteroids would be quite excellent for pew pew against things down on earth. It could cause a whole new level of cold war style standoffs.

Faith in institutions, including the government has declined since. Maybe it's a chicken-and-egg problem, but as much as I want to agree with this I can't.

Interestingly it's increased in the military since Vietnam so maybe we should let the Air Force take charge of this if it ever happens.

https://news.gallup.com/poll/1597/confidence-institutions.as...

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