Simulate Asteroid Impacts on Earth | Hacker News Reader

Simulate Asteroid Impacts on Earth

neal.fun

407 pointsfaebi137 comments

I've always had a weird fear whenever I was in Duluth that Lake Superior would get hit by an Asteroid. The lake itself seemed like a much bigger and more likely target.

A couple people have commented as much, but I wish this took water into account.

I feel like I read somewhere that the K-T boundary asteroid is thought to have been more destructive due to hitting relatively near land than if it had been in the deepest ocean. I don't know how that would compare to hitting land.

Shouldn't make that much difference. Average ocean depth is about 3km, and the asteroid was 10km in diameter, so ocean not much of a cushion.

It wasn't so much that it hit near land as it was the type of land it hit- lots of gypsum, which meant a lot of sulfates injected into the biosphere at once, enough to acidify the oceans to the point of food chain collapse. It really hit in just the 'right' spot in terms of maximizing damage.

Feature suggestion: Add an option to switch to metric units (even after 40 years on this planet I can't imagine much when you show me feet or mph).

Weird, for me (in an european country) every data appears in metric units.

The app probably uses something `navigator.language` to determine which unit to use. Unfortunately the browser doesn't expose any API to get the user's preferred measurement units. I assume it works for you because your browser locale is not en-us.

I'm confused. A 100 ft asteroid that explodes 2.2 miles in the air seems to result in far more deaths from a 0.6 mile wide fireball compared to a 200ft asteroid that would hit the ground in the same location (Fort Lauderdale, FL).

100ft = 211,172 deaths

Is this correct? https://imgur.com/a/Elst6Q3

Air bursts give a wider area of destruction than ground bursts.

I knew this was true for nuclear weapons. It was just surprising that a smaller asteroid could be that much more dangerous than a larger one due to potentially exploding in the atmosphere.

Much the same mechanism sans radiation.

For the same reason nuclear weapons detonate over the ground. Greater destruction. https://en.wikipedia.org/wiki/Air_burst

Digging a giant crater localizes the destruction and consumes most of the energy An air burst doesn't bother digging a giant crater and has a larger fraction of it's energy dumped into the atmosphere for fireballs, high winds, and direct radiation.

I thought asteroids didn't normally produce any direct radiation; their explosions are purely from being superheated by the atmospheric friction. (Obviously, nuclear airbursts do produce a lot of radiation.)

Well potential energy is turned into kinetic energy, which heats up the asteroid. Any water, or gas inside could well result in an explosion.

Things like turning night into day release a fair bit of radiation, like light.

The Tunguska event is thought to be an airburst, that flattened many trees (80M or so), made an incredibly loud explosion, and it's claimed it was nearly as bright as the sun.

That's not radiation though. When people talk about "radiation", they don't mean light, they mean ionizing radiation, not everything across the entire EM spectrum.

"Radiation" here refers to thermal radiation --- the direct radiant heat released through atmospheric friction and blast.

The shockwave itself is also radiant energy, in this case a kinetic overpressure wave.

Net impact effects are "wind blast, overpressure shock, thermal radiation, cratering, seismic shaking, ejecta deposition, and tsunami":

<https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/201...>

Remember that "radiation" simply refers to any effect that radiates outward from an initial point or source, say, a radiator. Yes, common parlance has abbreviated "ionizing nuclear radiation" as "radiation", but that's only one of numerous types of radiant energy.

When someone says "a nuclear bomb releases heat and radiation", the radiation they're referring to is not thermal radiation. You're being pedantic.

The link I provided gives alternate usage. You might wish to reconsider your position.

can we take a moment and recognize that neal agarwal (the creator of this site) has made an incredible body of work like this that continuously has us thinking, laughing, and interacting?

https://news.ycombinator.com/from?site=neal.fun

nice one as always, neal.

I adore people who build stuff like this. The “absurd trolley problem” was genius.

Fun, silly, sometimes a little weird, corners of the internet are what drew me in in the first place.

Every few years I check in on Zombo.com to make sure it’s still there.

It would be cool if it could factor in mountains - but I get why that is not an easy task. Fun isn't the best word to describe this page - but it was!

It's conceptually simple : use visibility based on viewshed for heat and direct blast concussion. Secondary effects (wind) would be harder.

But it's computationally extremely difficult, as you say.

Well, you could cheat.

There's so much cheap GPU compute used for mining shitcoins and training glorified Markov chains on Reddit dumps, surely someone could spare a few racks to run some CFD on a detailed GIS model of our planet, to create lookup tables that would allow everyone to cheaply simulate all kinds of fun events, such as nuclear detonations, asteroid impacts, "rods of god", relativistic kill vehicles, supervolcano eruptions, etc. anywhere on the planet, at the push of a button.

The social value of this would be immense - even if you and me never used those precomputed LUTs for anything, they would surely help Randall Munroe or Kurzgesagt or others answer even more high-energy "what-if" questions with even greater accuracy!

>surely someone could spare a few racks to run some CFD on a detailed GIS model of our planet, to create lookup tables that would allow everyone to cheaply simulate all kinds of fun events, such as nuclear detonations, asteroid impacts, "rods of god", relativistic kill vehicles, supervolcano eruptions, etc. anywhere on the planet, at the push of a button.

Nobody ever did a sequel to

https://en.wikipedia.org/wiki/SimEarth

shameless plug: https://store.steampowered.com/app/1482770/Terra_Firma/

I would love to mess with that, but I think it also be used for targeting weapons with even greater accuracy, not just theoretical questions

Security through obscurity?

A depressing picture that I agree with yet the way you left not a single thing unburned made me laugh. (Thanks, I needed it)

I don't think visibility would be all that hard to compute for the purposes of this site; I did similar calculations for radio "visibility" once (four thirds earth radius etc.):

  - Choose a grid of square cells of appropriate size (can be quite large here)
  - Put it on a plane tangential to an idealized flat earth ground at the center (easy in ECEF)
  - Offset by the desired height
  - Perform a "raycast" from the center cell to the center of each other cell
  - Calculate elevation from interpolated SRTM data along the way and store the maximum elevation* along the path (idea: something similar to DDA traversal through the SRTM data? Wouldn't be exactly linear, though…)
  - You can pretty much derive anything via linear algebra from there

* "Elevation" from the viewpoint of the chosen plane, obviously.

Visibility is not hard to compute. I said you could use "viewshed", which is the usual method of calculating line of sight to a given point from all points in an area. But it is a computationally intensive task to take a large enough area to accommodate any arbitrary asteroid impact. Orders of magnitude more than a web response, even accounting for down sampling and heuristics to restrict the size of the compute area.

Almost any GIS software package can do it for you.

https://en.m.wikipedia.org/wiki/Viewshed

What you're suggesting is that, except you didn't account for curvature of earth.

> Orders of magnitude more than a web response

That's likely where our different assesments come from, then. I was thinking more along the lines of "it's parallalelizable and easily offloaded to the client".

An addendum for completeness' sake, though :)

> What you're suggesting is that

Not entirely. I'd build a LUT of "how high up must you be to be visible here" per "pixel", instead of "is the ground here visible", which I'd argue is more useful for modelling here.

> except you didn't account for curvature of earth

I didn't spell it out explicitly, but that's not the case if you do your projections right. (And you have to project, as SRTM data is always relative to the EGM96 geoid.)

Where's my resulting tsunami info? ;-)

Came here to ask the same question :) I picked the impact location to be some ocean spot and it didn't kill anyone, I am not sure if that's optimistic.

Same. I just rewatched deep impact recently too so I picked somewhere off the east coast.

Edward Teller, the inventor of the hydrogen bomb and longtime head of Los Alamos National Laboratory, believed it was possible and even a good idea to place 1 gigaton yield warheads on orbital platforms for asteroid defense.

It might seem outlandish to us, but then again, so would a hydrogen bomb.

He's not entirely wrong. If we had a good way of getting a warhead to an incoming asteroid, it'd be a great safety mechanism. Unfortunately, today, there is no one trustworthy to put that sort of weaponry into somewhere that would allow it to strike any location on earth with less than a few minutes warning. Especially since something of that yield would devastate a large portion of earth.

Though lets be honest, anything in orbit is dangerous. A crowbar (aka Rods from God aka https://en.wikipedia.org/wiki/Kinetic_bombardment ) is even smaller and just as dangerous.

Imagine you we’re an insane billionaire with the ability to launch objects into say a lunar distance orbit. It wouldn’t require a lot of cold gas to drop some rods onto any spot on earth, and it would be undetectable until the explosion happens.

As space becomes easier to access the risk increases exponentially.

Well, fortunately we don't have any insane billionaires with the ability to launch stuff into orbit... /s

It would require quite a lot of it because you need to significantly change the orbit, especially if you want it to still be plenty fast on impact.

And it doesn't make much sense either. A billionaire can just pay a few millions to send a guy in a car bomb or a cessna full of explosives. It's way simpler and just as undetectable until the explosion happens.

IIRC nuclear weapons aren't very effective against asteroids in a vaccuum. Unless you can place the warhead inside the asteroid somehow.

Simple, just teach deep-core drillers how to be astronauts and send them to implant it.

That would make for a great movie, could be titled like it's the end of the world. Maybe Apocalypse Now?

A powerful nuke could certainly alter an asteroid's trajectory. However, most of the energy would be wasted. It'd be better to use a nuclear propulsion reactor strapped to the side of the asteroid to direct it more accurately, but we don't have that technology today, whereas we do know how to make big bombs.

Also, the idea of changing an asteroid's trajectory just before it hits the Earth is crazy. You need much more warning, because even a big bomb isn't going to move the asteroid that much, so you need to use it long before it's projected to collide.

Nuclear weapons which are optimized for wide surface area destruction or bunker busting are not very effective. Nuclear bombs like any bomb can be tuned to produce a variety of effects. See Nuclear shaped charges https://en.wikipedia.org/wiki/Nuclear_shaped_charge

Very cool. After trying numerous combinations of composition, velocity, and diameter... my takeaway is that most asteroids 70 feet or bigger would do substantial damage at 1 Hacker Way, Menlo Park, CA.

Too bad not everyone thinks in terms of miles, feet nor furlongs. I suggest you add an option for a metric system in your spare time. Otherwise great illustrative site!

Definitely more colorful than Nukemap. Would love to see something other than a simple circle for the various radii- surely the impact angle and local geography would shape the blast, no?

(I realize that is a very hard problem to accurately model.)

<click click click> this is fun, I should show it to the kids <scroll, scroll> hmm <scroll, scroll> ... <deletes from browsing history>

The kids have enough lingering anxiety from the pandemic I think

It's truly amazing how much stuff you can just dump safely in the middle of Lake Michigan. Of course... there's no calculation of the Seiche it would induce.

This was my experiment too - "What if it hits one of the great lakes?"

They become even more extraordinarily great lakes!

Some believe this has already happened.

https://www.greatlakesnow.org/2019/12/great-lakes-meteorites...

Lots of fun, Neal's work is always very impressive - not only on the technical implementation level, but the creativity as well.

Cool! Some info on tidal waves for water hits would be even cooler

It seems to me that the estimates of how frequent a given impact happens are off. An impact by a iron meteorite 200' in diameter at a speed of 20k MPH and 90 degree angle does not happens on average every 454 years.

When was the last time any that size rock impacted the earth?

I think it's just based on impact energy

so for fun, i threw one at Los Angeles. Downtown specifically. By the animation of the fireball and sonic waves, it seems quite devastating. My question is if the fact that downtown LA is in a bowl, would the surrounding mountains lessen the devastation at all compared to the exact same asteroid hitting somewhere else much more flat like say Dallas? Like, would Burbank be less destroyed from an LA impact than say Frisco outside of Dallas with nothing to lessen/deflect?

then again, it's california, so the seismic damage might just set of the Big One(tm) resulting in even larger damage as california would just split off into the ocean giving arizona some much needed ocean front property finally.

Why do we enjoy simulating our own destruction so much?

I was seeing how big/fast an asteroid that hits New York would have to be to hurt me in Boston. Turns out it would have to be larger than I thought.

Would be nice to be able to click a place on the map and see how survivable that location is.

> I was seeing how big/fast an asteroid that hits New York would have to be to hurt me in Boston. Turns out it would have to be larger than I thought.

Did the same on my area with that infamous nuclear bomb simulator/map. Some of the historical warheads seem surprisingly weak relative to modern city sizes. That said, in both nuclear and asteroid impact scenarios, do consider that, while you may be out of range of the thermal and pressure waves, you might still be in range of "extreme disruption caused by survivors closer to the blast moving outwards, emergency services moving inwards, and the economy and social order going to shitters as the country deals with what happened" wave.

I can only recommend Threads (1984) if you want a glimpse into just how utterly bleak post-apocalyptic life might be.

https://archive.org/details/threads_202007

I tried dropping a big asteroid in an airport near me, ended up killing millions and causing mass property damage across the entire southeast.

I think this needs to be optimized for impacts that hit water and the effects that would have, because right now it doesn't do that so it feels a bit generic.

From the other comments here it would appear that this site uses imperial units, but I see it as metric. And no option to switch... Is this being inferred from my location?

Anyway, most deaths I've been able to get is with a gold asteroid, max width and speed, impacting near Dindori, India. The fireball would kill about 448 million. Impact angle makes very little difference.

It probably uses your default language settings; I'm in the EU with the OS set up in English and I see imperial units.

Is it just the Baader-Meinhof phenomenon ("a cognitive bias in which, after noticing something for the first time, there is a tendency to notice it more often") or do asteroid impact related things always go for Manhattan? I open this map and, bam, there's a map zoomed right onto Manhattan and a "select impact location" prompt.

Or sometimes Tokyo.

They've already got earthquakes and tsunamis, can Manhattan not have the asteroids? (Says the European, dodging all natural disasters)

I do remember Paris being destroyed in one film - armageddon perhaps. O’Neill comments on it in an SG1 episode.

Why is that cities in the northern hemisphere are always the ones destroyed in fiction? There's cities in the southern hemisphere too: destroy some of them!

Actually, I want to call out "The Expanse" for this (warning: spoilers): in the episode where one of Mars' interplanetary nuclear missiles gets through Earth's defenses, it strikes South America. But this is the only time I can think of this happening in disaster fiction; usually the entire existence of the southern hemisphere is ignored.

I think the name itself is a bit of a meme for blast radius calculations and the like.

Well, they go for Manhattan first, but then the second one is usually Berlin.

Typically true for those from a Leonard Shower.

Can't help but wonder what the heatmap of location choices looks like for everyone using the app.

Which is worse, a mile wide fireball in the sky or a mile wide impact? Seems all bad to me.

Nukemap: Visualize the extent of nuclear detonations

https://nuclearsecrecy.com/nukemap/

Found a bug, if the impact point is near the south pole/north pole, the regions aren't distorted to match the projection of the map.

First place I launched, the asteroid landed NE of New York City. One of the places just outside the crater was a town aptly named Dodgingtown, Connecticut.

If you are Brazilian, you can only think of Brasilia when you see simulators like this one. It's always your top of mind first target place.

Interesting.

What's the axis orientation for "angle"?

Perhaps estimations for not-just-normal-to-the-plane impact trajectories with entry angle and heading?

Cool, nice addition would be to recognize sea or ocean and then calculate size and destructive power of a tidal wave.

I am a bit underwhelmed I can't get an asteroid there that will allow me to completely destroy life on Earth.

Yeah.. The biggest fastest asteroid doesn't seem to cause a planet wide issue. What killed the dinos then?

Jk... I do not have enough info about the dino extinction, and I understand this is a fun internet toy. Very cool and neal.fun is amazing in general.

[Feature Request] If the asteroid falls into the sea, there should be a simulation for tidal waves.

An impact this size happens on average every 25,000 years

A comet on default settings. T-that can't be right, r-right?

Don't worry, we're overdue a climate-altering / mass-extinction-triggering supervolcano eruption anyway.

I'm sure you know this, but just to point out, we're no more "overdue" for a supervolcano because it's been longer than average since an eruption than a gambler is "due" to win because they've pulled the arm on their slot machine enough times. (Though iirc some volcanoes are periodic. But unless I'm quite mistaken, supervolcanoes aren't periodic globally.)

Is there really no memory in this process? I imagine to some extent, some tensions would be building up or something like that.

I don't feel qualified to say there is no "memory", if I make claims any stronger than I've made already I'll be out of my depth, but see the information below for instance:

> Most volcanic systems that have a supereruption do not have them multiple times. When supereruptions do occur more than once in a volcanic system, they are not evenly spaced in time.

https://www.usgs.gov/faqs/yellowstone-overdue-eruption-when-...

I think these are just very complex systems with many different factors, like the kind of rock they're under, what's going on with the continental plate at that time, etc. We don't have a good understanding of what's happening in the mantle, which is especially relevant for hotspot volcanoes like Yellowstone that are fed from the mantle (note that this is not how all supervolcanoes work).

Allow me to leave you with an awesome animation of the formation of a very different supervolcano: https://youtu.be/sx3_WJHAERc

no need to need luck - we'll extinct ourselves with co2 quite soon, gg

All y'all in here worrying about once an eon events when CMEs be like "shit I'm late for my centennial"

There’s currently controversial archaeological evidence for a younger dryas (12,900 years ago) meteorite impact which caused mass global cooling, though thats one of several theories.

There’s also speculation and some small amount of material evidence that a meteorite airburst the middle east/levant[1] maybe leading to myths of cataclysm like Sodom.

The 1908 blast at Tunguska in Siberia is now widely regarded as a result of a cosmic airbust.

There seems to be a growing body of evidence that large, city-destroying asteroids are actually quite frequent in geological terms. The odds of hitting an actual city are low, but I don’t like those odds

[1] https://www.livescience.com/64179-ancient-cosmic-airburst-mi...

Certainly the Chelyabinsk event should give us all some pause.

That means that size would happen on land about once every 100,000 years, and about 1/3 of those wouod land in a desert (mainly Antarctic, Arctic tundra, or Sahara)

There's something immensely satisfying with the idea of a 500m space rock vaporizing Jersey City!

pretty neat. I wish it would tell you an approximate terminal velocity for the mass of your asteroid.

Third field down after simulating the impact.

There is a nice calculator for terminal velocity of a sphere in air here:

http://hyperphysics.phy-astr.gsu.edu/hbase/airfri2.html

That being said, I'm not sure how relevant terminal velocity is for anything but the smallest/slowest ends of the parameters of this app. For an asteroid going 38,000 mph (default speed on linked page), drag just doesn't play a big part - the asteroid passes through the atmosphere in ~5 seconds, not enough time for it to slow down significantly.

Speed is limited to 100km/s, our Voyager 1 is going 17 km/s doesn't sound so fast.

I remember a similar app - way less sophisticated - at the Griffith Observatory in Los Angeles.

this is not taking into acount the elevation data from the geography, it is assuming everything is on a flat plane... elevation would be nice, like a mountain would act as a barrier or something

I could kill approx 500 million people in the fireball. Anyone higher?

Interesting to see the usage of Apple Maps! Any specific reason?

I wonder if there's a log being kept? I'm at least mildly curious what percentage of visitors immediately pan over to Moscow and let one rip.

It'd also be interesting to break it down by geolocation of the visitor's IP address.

this only goes up to one mile. Chicxulub was six miles.

Sure, but the simulation doesn't include secondary effects like no photosynthesis for a few years.

How many people tagged NYC with an asteroid? Just wondering.

Trump at his place in Florida. Felt quite satisfying.

Oh the conspiracy theories that would cause.

Get well soon!

this reminds me of the most excellent robert-heinlein book "the moon is a harsh mistress", "we will throw rocks at them" !

highly recommended.

tanstaafl

Please at least make it in normal units which everybody use, not in glass of milk per hour or something.

Well, that was fun

I'm not very good in successful HN titles, therefore I let ChatGPT write that one for me with this prompt:

Rewrite the following twitter message as a hackernews title. It should be as successfull as possible and attract many readers

Original Tweet: New page! Make your own asteroid and launch it at Earth to see the effects.

This is simply insane at this point.

More than, that, if "Simulate Asteroid Impacts on Earth" is really what ChatGPT came up with, then color me impressed - it has done its job perfectly.

I want this for git commit messages.

I tried it just for fun yesterday: transforming Git commit message whose subject are too long and that are not in the imperative tense into short title using the imperative tense.

For this kind of thing it mostly works.

Did you try to post the patch and ask for a commit message?

Can it be used offline to, for instance, shorten the names of top secret projects?

You can use it online to shorten the names of top secret projects, but then they are no longer secret, and you will lose your job if/when your org works with OpenAI, which they should be.

Until it’s offline, sadly, I can’t even use it for company work.

https://devforth.io/blog/gpt-j-is-a-self-hosted-open-source-...

Do you mean this?

https://github.com/RomanHotsiy/commitgpt

Self-programming systems inch closer, and with that, the technological singularity.

When this happens, the machines will decide they don't need us any more and we'll be eliminated. I'm not entire sure the machines would be wrong.

"I'm not entire sure the machines would be wrong."

Well and if that mindset is coded (subconsciously) into the AI, it will happen as a self fullfilling prophecy.

But as of right now - the machines absolutely would need us. There is no machine capable of self replicating anywhere close in sight.

And when that happens I'll be in my garage working on EMP devices.

Resistance is futile.

Rob the casino first.

This is very cool, I can't wait until this is freely available. I wanna run it locally and screw around with it!

Chat GPT is freely available.

No need to wait! The singularity is nigh upon us.

https://openai.com/blog/chatgpt/

https://chat.openai.com/chat

What was your prompt for this comment?

I didn't think about going that far, but yes, that would have been the way to go.

Weird, for me it doesn't return anything close to this.

> "Discover the Ultimate Asteroid Simulator: Create and Launch Your Own Asteroids at Earth and Observe the Results"

> "Create and launch your own asteroid on Earth to see the impact - new interactive page now available"

> "Create and launch your own asteroid with our new interactive tool"

> "Create and Launch Your Own Asteroid to See Its Impact on Earth - A Must-Try Simulation for Space Enthusiasts!"

Sigh. What am I doing wrong?

This isn't the first time I've struggled to reproduce HN CGPT results.

https://news.ycombinator.com/item?id=33869423

Okay Google, tell Alexa to ask ChatGPT to apologize on my behalf running out of DALL-E credits to generate a meme reaction image to post on what's left of Twitter and Reddit.

The future isn't going to end well: there will be a bazillion bots catfishing and manipulating humans into doing who-knows-what possibly on the scales of the Pizzagate conspiracy theory, SWATing, sexting exploitation, and let-your-imagination-run-wild. Maybe people will catch on, decide to opt out of social media, and go fishing for actual catfish (the things can be damn heavy).

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