ESA announces upcoming asteroid impact.

[Dartz]

Unfortunately, it's a #fictionalevent as part of an excersise for Planetary Defense Conference to decide how to actual deal with an incoming city killer  and who needs to know what, and what if anything to do about it?

Had my hopes up for a minute but so it goes.

There's a fairly shite article from CNeT here

ESA's Twitter account is roleplaying the end of a small part of the world

So if we can redirect it, where exactly do we want the asteroid to land?

Oh sweet meteor of death.
Fall upon us and deliver us in fire
To peace everlasting

[robkelk]

Facebook HQ. Try ignoring the laws of nature the way you ignore the laws of countries, guys.

[hazard]

Well, when it comes to forcing the impact into a place less harmful? Well, if it's possible you want to crash it into Antarctica, into the ocean as far away from land as possible, or an uninhabited stretch of land that's preferably also not forested, and with as steep a trajectory as possible. The ocean is not a bad choice, but the impact is likely to cause tsunamis, having it land in an uninhabited stretch of land comes with rocky ejecta and dust, and the smoke from any ignited forest fires if it lands in a stretch of forest makes this worse. Antarctica is the best choice here because it's not floating on the ocean but still a very large, thick layer of ice that interacts well with the atmosphere and gets deposited back down fast.

You want a steep trajectory because that forces most of the force and energy deeper into the planet. The shallower the trajectory, the more of the energy gets used to create a spray of debris.

[Labster]

I'd recommend having it hit the Irish Data Protection Commission, because if it took the whole office no one would notice any difference.

[Dartz]

I'd recommend having it hit the Irish Data Protection Commission, because if it took the whole office no one would notice any difference.

You could say that for most of the Civil Service here.


Two Civil Servants meet each other in the office canteen. "Can't sleep either?" asks one.


I've to deal with them and I've never met a group of people more aggresively unwilling to do their job .

[classicdrogn]

At first I was thinking DC, but the Smithsonian's main exhibit halls and the Library of Congress are there. More seriously, Antarctica is probably a good choice but seems like it would be difficult to get the angles right for a polar approach. Looking closer to the equator gives several desert areas that would probably not take much note of a new crater and a few days of extra dusty air.As long as they don't mess up the calculations and drop it on a cultural site that sets off a holy war it's probably fine. On top of someones "secret" illegal weapons program site would be darkly hilarious, but that kind of precision seems unlikely with a randomly shaped rock of unknown and uneven composition.

[robkelk]

... More seriously, Antarctica is probably a good choice but seems like it would be difficult to get the angles right ...

I read that as "it would be difficult to get the Angels right". Second Impact, anyone?

[Rajvik]

Hitting the ocean is the last bloody place we want one to hit. Given odds its a higher likelihood granted, and the Pacific more likely than the Atlantic. That happens though, we're looking at a world spanning tidal wave tall enough to probably scour the pacific coastlines.

Hitting the Antarctic or the arctic would require the asteroid to either be coming in off the elliptic or would cause it to skip which as you pointed out would be a bad thing

Drogn has the right of it, try and hit a desert stretch with it if it has to hit.

[Norgarth]

If possible re direct it to strike the Moon. Luna's been Earth's shield for billions of years.

[ECSNorway]

Hitting the ocean is the last bloody place we want one to hit. Given odds its a higher likelihood granted, and the Pacific more likely than the Atlantic. That happens though, we're looking at a world spanning tidal wave tall enough to probably scour the pacific coastlines.

Hitting the Antarctic or the arctic would require the asteroid to either be coming in off the elliptic or would cause it to skip which as you pointed out would be a bad thing

Drogn has the right of it, try and hit a desert stretch with it if it has to hit.

If possible re direct it to strike the Moon.  Luna's been Earth's shield for billions of years.

These.

We do NOT want a tidal wave to make the one as caused Fukushima to look like a splash in a wading pool. We really don't.

The last time we had one this big, well, there used to be a great big wide open plain connecting Britain to Mainland Europe, place called "Doggerland". It... ain't there anymore. 

"Somewhere in the desert" is our best bet, preferably somewhere in the Sahara well away from anywhere populated. Or, y'know, the moon. That's how it got all those nifty craters you like to point your telescopes at.

[Norgarth]

I thought Doggerland was simply inundated by rising sea levels when the Ice age ended.

On the other hand, there's the example of the Chicxulub crater next to the Yucatan peninsula, which lead to massive extinctions at the end of the Mesozoic Era as an example of a sea based strike

[hazard]

I ran the numbers into an impact calculator with the following settings, presuming a general worst case scenario for size and density, so 300 meters wide and solid iron, the most common angle of 45 degrees, and a slightly above average speed at 20km/s.

Total energy release was 7.65x10^18 Joules, or about 2 000 MT of TNT equivalent. That sounds like a lot, and it is a lot. Of that energy about 90% is impact energy.

But the Sendai earthquake released 3.8X10^22 Joules, more than 9 000 000 MT of TNT equivalent.

Frankly, unless that asteroid hits an ocean close by an island, any tidal wave it generates is likely to be irrelevant compared to everything else it does.


Also Doggerland flooded as sea levels rose and the latest ice age mostly quit. And Chixculub is a poor example for the damage a sea based strike does; at the time of the dinosaurs Chixculub was a rather shallow sea, while the tidal wave did tremendous damage, it did not do as much damage as the massive fan of debris and ejecta that traveled the world and lit a good chunk of it on fire. That's what killed the dinosaurs, the massive global cool down that resulted from all the dust and soot in the air following the impact.

[Dartz]

They've projecting it to hit somewhere between lLos Angeles and the Southern Indian Ocean.

That's a big projection.

On a 100/1 shot.

If this were real I'd be betting a tenner on those odds. There';lll be at least an hour or two to collect the winnings before the ejecta cloud roasts the planet.

http://blogs.esa.int/rocketscience/2019/...al_impact/

[hazard]

Oh come one, it's just an 800 MT impact at the most. It won't have global results, not in that way. And frankly? From the Southern Indian Ocean to Los Angeles is a lot of water. If it hits close by land whatever bits of land are close are fucked, but that's about it.

Of course, if that were to hit anywhere in the Netherlands I'm dead. Seriously. If the Tsar Bomba were to be detonated at optimal height in the exact center of the Netherlands the whole country would die. And a good chunk of Belgium. And that one was only 50 MT.

[ECSNorway]

The current thinking on the Doggerland flood is that it was actually a tsunami driven by a massive undersea avalanche. Water levels were already rising and innundation was inevitable, but without that it would have been a much more gradual thing.

[classicdrogn]

I found an interesting video about desert glass that theorizes it was made by a Tunguska-like air burst from a disintegrating meteorite ala Shoemaker-Levy - I've linked to the conclusion starting about 38 minutes in, but the whole thing is worth watching if you have the time. Teal deer version: No, breaking a big asteroid up is not likely to make the situation better.

Nope, not embeddin' it

[hazard]

Yup, generally speaking if the rock's small you want it to disintegrate high in the atmosphere, where the heat and shockwaves will dissipate over a large area.

If the rock's big enough though? You want it to hit. The more energy sunk into the Earth directly the less energy ends up in the atmosphere as heat and shockwaves.

[Norgarth]

plus shattering it just means you're receiving a load of cosmic buckshot

[classicdrogn]

Indeed. A few minutes on from where I linked the video, it mentions the dude being covered finding what he thinks is geological evidence of that kind of strike happening some millions of years ago and turning pretty much the entire continent of Asia into a firestorm.