If an extinction level astroid was heading straight towards Earth

[Darththeo]

Why do people think that having the Asteroid in smaller parts come in would be better than coming in whole? The amount of energy transferred to Earth will be the same regardless unless you destroyed mass.

[Deleted]

So if you tape a firecracker to an empty coke can and set it off, the explosion will send the can flying.

If you landed a spacecraft on the periphery of the asteroid and the spacecraft had a nuke on it, when you detonated the nuke wouldn't it act like a rocket and push the asteroid off course a bit? The nuke would push against the surface of the asteroid?

Yes, but in the case of a worldending asteroid the coke can is filled solid metal all the way through and the firecracker is the size of a grain of sand.

[Orby]

They wouldn’t tell us about it if there was nothing they could do. Don’t want mass hysteria and panic.

Well I hope they give us some warning, my last moments before I die don't want to be on the toilet taking a poop :P

[Seranthor]

Do you think we would nuke it? Let's imagine for a minute that this thing was fairly close, we couldn't catch it in time to react in a uniformed manner due to a blind spot or such.

https://www.space.com/39971-asteroid...omb-study.html

It sounds like we'd basically have to throw every nuke we have at it from every nation. We don't have nukes big enough currently and most likely never will to actually 1shot an astroid. It would be a ridiculously big bomb the size of a house basically.

Do you think we'd survive or are we fucked if one decides to head for our tiny blue planet? Would everyone band together to destroy it?

Short answer, we are fucked..

[Gadion]

I would prefer if we could somehow accomplish speeding it up instead

[Raelbo]

I saw what you said, it's just wrong.

As an engineer who has actually studied subjects like physics, maths and applied mathematics I'd be very interested to hear the basis of this assertion.

The blast would either slow the asteroid (and possibly alter it's trajectory) enough to avoid it coming close enough for collision.

No it wouldn't. The blast would be massively insufficient to alter the momentum enough to make the required difference.

Think of it like a plane encountering a head on wind during it's flight and arriving late.

A shitty analogy. The relative ability of air to slow a plane is many orders of magnitude greater than that of a nuke to slow a 10KM asteroid. A better analogy is to think of the bugs that splatter on the windshield and the effect they have on the arrival time.

The distances/speeds involved in the asteroid scenario are so gigantic that it only take a small amount of speed bled off from the blast to allow the Earth to be well clear before it arrived at the collision point. To put it in perspective, the Earth travels 5-6 times it's width in an hour.

I already did the maths. Either tell me where I erred, or recognise that I am correct (or at least in the ballpark) instead of trying suck some random perspective out of thin air.

The blast would be much bigger than anything ever used/tested on Earth, it would easily be sufficient to slow the asteroids approach enough to avoid collision.

Just do the maths. You'd then see how wrong you actually are. To be successful we'd probably need a blast thousands of times greater than we have the ability to create with our current levels technology.

[I Push Buttons]

Why do people think that having the Asteroid in smaller parts come in would be better than coming in whole? The amount of energy transferred to Earth will be the same regardless unless you destroyed mass.

Would you rather be shot by 1000 Nerf darts (.465 Joules per dart with a 1g dart traveling ~100fps) or a 9mm bullet (467 Joules from one 7.5g bullet traveling ~1173fps)? Same amount of energy so they are exactly the same, right?

[Dsonsion]

Why do people think that having the Asteroid in smaller parts come in would be better than coming in whole? The amount of energy transferred to Earth will be the same regardless unless you destroyed mass.

Many reasons for that. I'll try to list the two or three big ones off the top of my head:
The resistance of wind is actually a force which can be approximated to being proportional to the speed of the object.
A smaller object is therefore going to suffer a greater deceleration.
Volume/Surface ratio also comes into play here, and it will also affect the likelihood that the different parts break into even smaller pieces.
The pressure applied to the earth's surface, or most likely the ocean's, upon impact is going to change if it's a larger amount of smaller projectiles, causing less deformation per point of impact.

[Lawlhero]

The sad thing is, we have the money to put into development systems and technologies that could probably redirect an asteroid, if we had just one thing in this world where everyone worked together, and isn't politically or monetarily motivated.

[Sialina]

I doubt we are capable of deploying most nukes below LEO, and hitting it that close is meaningless. The problem is not the nukes, the problem is getting them to escape earths gravitational pull. We don't have enough rockets to launch them fast enough.

[bloomy]

the first day or 2 would be spent peeling the batman costume off ben affleck, then we'd just need to round up bruce and the boys so they can go pop that bitch in half. i think we can all agree that in real life bruce is going to let ben keep that short straw and die for us, and ben would happily do it. such a batman move.

[Zaktar]

As an engineer who has actually studied subjects like physics, maths and applied mathematics I'd be very interested to hear the basis of this assertion.



No it wouldn't. The blast would be massively insufficient to alter the momentum enough to make the required difference.



A shitty analogy. The relative ability of air to slow a plane is many orders of magnitude greater than that of a nuke to slow a 10KM asteroid. A better analogy is to think of the bugs that splatter on the windshield and the effect they have on the arrival time.



I already did the maths. Either tell me where I erred, or recognise that I am correct (or at least in the ballpark) instead of trying suck some random perspective out of thin air.



Just do the maths. You'd then see how wrong you actually are. To be successful we'd probably need a blast thousands of times greater than we have the ability to create with our current levels technology.

Your math appear to assume we are trying to slow the asteroid (speeding it up would have the same effect, i wonder if it would be easier?) Most of the articles I've read on this subject talk about altering trajectory, which appears well within our capability. It's detection that's going to kill us, not lack of sufficient force.

[Darththeo]

Would you rather be shot by 1000 Nerf darts (.465 Joules per dart with a 1g dart traveling ~100fps) or a 9mm bullet (467 Joules from one 7.5g bullet traveling ~1173fps)? Same amount of energy so they are exactly the same, right?

Are we talking getting all the darts at once or just one at a time ... because it isn't the same transfer of energy. Did you fail high school physics? Would you like one ton of sand dropped on you at once or a one ton boulder?

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Many reasons for that. I'll try to list the two or three big ones off the top of my head:
The resistance of wind is actually a force which can be approximated to being proportional to the speed of the object.
A smaller object is therefore going to suffer a greater deceleration.
Volume/Surface ratio also comes into play here, and it will also affect the likelihood that the different parts break into even smaller pieces.
The pressure applied to the earth's surface, or most likely the ocean's, upon impact is going to change if it's a larger amount of smaller projectiles, causing less deformation per point of impact.

Except the overall effect to us would be the same. It would effectively cause a mass extinction that humans would be unlikely to survive.

[I Push Buttons]

Are we talking getting all the darts at once or just one at a time ... because it isn't the same transfer of energy. Did you fail high school physics? Would you like one ton of sand dropped on you at once or a one ton boulder?

One ton of sand, thanks.

[AwkwardSquirtle]

Of course we wouldn't just nuke it. We'd send Bruce Willis up with a nuke to drill inside it so that it's blown up from the inside. Obviously.

[Gadion]

One ton of sand, thanks.

You'd be equally dead in both cases... but I can't help but be curious... anyone have any thoughts on potential magnitudes of "shplat"?

[Darththeo]

One ton of sand, thanks.

And you are still crushed to death ... the result is the same. Your body isn't going to be in any better condition.

You are the guy who thinks it is better to get hit by a ton of feather than a ton of bricks aren't you?

[schwarzkopf]

Do you think we would nuke it?

Nuke wouldn't help if it was that close.

[Nerovar]

We'd make up wild conspiracy theories about how the asteroid was a hoax invented by the globalists to trick us into giving up our nukes.

[Raelbo]

Your math appear to assume we are trying to slow the asteroid (speeding it up would have the same effect, i wonder if it would be easier?) Most of the articles I've read on this subject talk about altering trajectory, which appears well within our capability. It's detection that's going to kill us, not lack of sufficient force.

My maths was addressing directly @caervek's scenario. That being said the implications of the maths are pretty much the same. Whether you're trying to slow it down, speed it up, or move it sideways you still require to apply a similar amount of momentum to the object. And the amount of momentum we can apply to an object big enough to cause an extinction level event (ie like the one that wiped out the Dinos - ie a 10KM asteroid) falls massively short of what we'd need it to be.

It's a matter of scale. The Russians claiming that they think they can take out a 200m Asteroid using a nuclear weapon is one thing. Deflecting an object 125000 ties bigger than that is another matter entirely.

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One ton of sand, thanks.

Bear in mind that it's molten sand....

That's the real problem. If you broke up the asteroid into tiny trillions of tiny shards, they'd still create the same amount of heat when impacting the atmosphere. Large meteors can actually cause burns and eye damage (like arc-welding). Now imagine a scenario where this effect is amplified by a factor of millions. If a 10km asteroid was converted to small stones and they all hit the earth, burning up in the atmosphere, every living thing on the planet would be burnt to a crisp.

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We'd make up wild conspiracy theories about how the asteroid was a hoax invented by the globalists to trick us into giving up our nukes.

I'd tend to agree that until there is incontrovertable evidence of the impending catastophe, people would come up with all kinds of rationalisations to avoid committing the tax dollars (or other currency) of "hard-working" Americans (or insert any other nation) to prevent something that may or may not happen.

And the way that asteroid tracking works, it's not sufficiently accurate enough to predict with absolute certainly what the trajectory will be going into the future. For example, let's say we actually spotted an asteroid that was on a collision course with earth 10 years before it was due to hit. The problem is that when we first detect it we'll only know for certain that it will pass somewhere in the vicinity of earth with, say, a 5% chance of collision. At which point a leader like Trump will dismiss it and say that the economy is more important than worrying about low probability of getting wiped out by an asteroid in 10 years time. Even if put to the vote, most voters would rather avoid a $5000 a year increase in taxes to fund the program to stop it. And so we'd proscratinate, for years until finally we can all see the bloody thing with our own telescope, and the scientists can tell us that yes, they are 99% certain that it will hit us and wipe out 99% of humanity. But by then it will be too late to stop it, so again we'll vote not to raise taxes on a futile effort, and rather just enjoy the last year.

If you doubt this, just look at how the climate change debate has been going.....