An Asteroid Could Destroy the World Before Impact
lithub.com
lithub.com
Mistake #2, objects that we find which could hit us get within range of our rockets only a finite number of times. For a previously unknown large object with a several year returning orbit, that finite number is likely to be 2 - once when we found it and once when it comes back (at which point it is too late). A more realistic version would be that it is on a long trajectory that will hit Earth after 3-4 times. Which gives us a lot longer to prepare, and a clear timing on when we want to try to hit it.
I won't comment on the cultural mistakes. Except to note that "We're going to get hit but odds are good that it is over water and nobody gets hurt" might be less panic inducing than the story claims.
It also applies to asteroids, and is a standard concept used in these scenarios. See e.g. the materials from the exercise at this year's Planetary Defense Conference [1] (the story on LitHub is basically a variation on that scenario, which also features an asteroid splitting in two during the deflection attempt, a failure to use nukes, and a city destroyed by the impact: New York).
> objects that we find which could hit us get within range of our rockets only a finite number of times
There are more and less viable launch dates, clustered in launch windows, but the details vary depending on your vehicle and the orbit. JPL's NEO Deflection App [2] has several illustrative examples which you can play with, and which work pretty much as in the story.
I guess that the big question mark is time. If we know the path of the asteroid very precisely, and the path of the Earth very precisely, but we don't know exactly when the asteroid goes down that path, it would result in something like a risk corridor depending on where the asteroir was between leading and trailing the Earth at the point of impact. I wouldn't (in fact didn't) guess that.
Thank you for the references!
Nowhere in the article does it talk about "destroying the world." You'd suppose they were referring to some kind of near-miss from a massive body causing, I don't know, gravitational forces or something.
What it's actually saying is that there would be a lot of panic in the run-up to an impact, so that even a relatively small event could cause oil prices to spike and real estate values to drop in the impact area.
Hardly anything at all like the headline suggests.
In the 2015 PDC exercise [1] the asteroid is also split in two by the first deflection attempt (that happens a lot in these exercises, see also 2017 and 2019) and the new bulls-eye is in India. So India plans a nuclear deflection attempt, but China vows to stop it, by intercepting it if necessary, because the second deflection attempt could result in the asteroid hitting China instead.
Meanwhile Iran, also in the new risk corridor, but not in the old one, threatens retaliation against the countries behind the first deflection attempt if it's hit: the Great Satan (aka the US), EU, Russia and China.
Bottom line: a recurring worry in these asteroid deflection scenarios is that whoever changes the trajectory becomes responsible for hitting whatever ends up being hit, and if that happens to be a nuclear-armed country, the consequence could be WWIII.
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.
https://nuclearsecrecy.com/nukemap/
Excellent calculator & visualization
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
(700000000 - 18000) * 3 = 2,099,946,000 sq miles of heavily damaged things
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.
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.
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."
http://devinit.org/post/global-humanitarian-assistance-repor...
"...the US remained the single largest donor, providing almost a third (32%) of all assistance"
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...
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?
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.
In all seriousness, what can be done about this sort of thing(mitigating it)? Opinions(albeit ones from the internet) range from spacecrafts intercepting and mounting thrusters to divert the object's course, or planting nuclear bombs, and other "fantastic" sounding solutions. Is there anything to be done other than expect the unexpected?
The most important thing would be to make sure that we can see these things well in advance. No defense is going to work if you don't see the threat at all. Currently we can't see well in the region enclosed by Earth's orbit, in the direction of the sun.
The B612 foundation was going to launch the Sentinel Space Telescope for that purpose, but they lost their funding. https://en.wikipedia.org/wiki/Sentinel_Space_Telescope
The key, of course, is being prepared well ahead of time, and looking for these things. We're doing a terrible job of these.
If you're a stupid species like the dinosaurs and don't bother to prepare for these things decades in advance, then there's nothing to be done; just let it happen.
If you can lob one at an asteroid with a multi-year period as it passes near Earth, you can totally, reliably solve the problem for quite cheap. I'd like some significant redundancy in the mission just to be sure, but it wouldn't be that hard, inasmuch as one can say that about anything in space.
The situation gets once worse once that ceases to be an option. When you're back to using electromagnetic forces by touching it in some manner, by landing, pushing, exploding, whatever, you've suddenly got a lot more problems.
That's my whole point: if we were more serious about this, we'd have orbital observation platforms looking for all these objects and keeping track of them all, so that we aren't surprised by anything short of another asteroid from totally outside the solar system like that one a couple years ago.
We laugh at the flat-earthers, but I think you can estimate how sane an Earthling is by its attitude towards meteor defense.
My point is most of us are "flat-earthers" after a fashion. Most people don't really internalize physics and the structure of the Universe[1], but when you do, you have these moments where your mind resolves the inconsistencies in your worldview and it expands and these mind-blowing vistas spread out before you.
One thing you realize is that the sky is fucking terrifying.
The world includes gigantic explosions that happen literally out of the blue for no real reason other than there are falling rocks in the sky and gravity.
[1] If we did, solar power would have taken off the moment someone thought of it. The Sun is awesome.
The Democratic Republic of Congo, a near-failed state, managed to evacuate 300,000 people in three days from a Volcano. I'm pretty sure suburban Texas can handle it.
Let's say a forecaster projected the impact location and area of mortal danger, and you found out your house is 100 feet outside of the projection. How confident would the forecaster need to be for you to be comfortable staying home for the event?
Has humanity sat up and decided to take this threat seriously? Nope.
Most likely, this was a test from some aliens to see if we're smart enough to avoid a much larger, extinction-level asteroid headed our way, and to try to get us to prepare ourselves better without violating the Prime Directive too badly. We failed.
Save the day, collect the gratitude of a grateful nation, and then sell off all the property at an obscene profit to make back all the costs.
Tldr: asteroid defense is quite hard. Currently we are not adequately equipped to do so it safely.
That said, I agree with you, its stupid to blow up an incoming asteroid so that it can basically shred all of the satellites in orbit and cause a Kessler cascade and make it difficult if not impossible to put things in orbit for decades. But in defense of my comment, you have to work within the confines of the story, that is the rule of improv.
The real tricky part is delivering the energy to the asteroid in a way that causes it to actually break up. The nuke needs to be drilled down below the surface of the asteroid so it doesn't just heat up the surface, potentially fusing it into a more solid chunk.
Of course the actual effects are hard to predict. Maybe we should be flying around right now blowing up random asteroids? First job for Trump's Space Force?
Let's assume we don't do multiple launches and orbit rendezvous.