Asteroid defense ideas

[Moontanman]

9 minutes ago, Mordred said:

Can you answer what happens if a radiated asteroid enters the atmosphere ? We cannot assume you will get 100 percent deflection.

Yes, if an irradiated asteroid enters the atmosphere it would drag the radiation it contains with it but it would only be the radiation from the nukes, how ever many modern nukes it took. 

9 minutes ago, Mordred said:

Secondly I mentioned you do not get the kinetic explosion that you do in the atmosphere. So you require higher a  megaton explosion to get the radiation caused outgassing. The 100 Megatons is simply a random approximation.

I am well aware of the blast effects in and out of the atmosphere, no one has a 100 megaton nuke and I see no one making one or being able to launch such a huge nuke and detonating it in the atmosphere would not work, the kinetic energy and mass of the asteroid would still impact the earth and you get the radiation too. So why would anyone so that? 

9 minutes ago, Mordred said:

As far as EMP the 1/r^2 relation is well known and understood it doesn't require citation.

No, you made an assertion that defies the physics of how an EMP works, you need a citation on that. 

9 minutes ago, Mordred said:

Lastly if you read back a page or two I mentioned nukes could be safely used provided you can

100 percent guarantee total deflection 

I say that is not necessary the amount of radiation released would be trivial over the entire earth compared to what we already have.  

Edited May 25 by Moontanman

[Mordred]

Funny how you made previous assertions that there is no risk due to radiation for the last couple of pages with others pointing out those errors yet you seem to think I'm incorrect for correcting you. 

An EMP emits gamma radiation that can cause nuclides Swansont also mentioned that detail previously the 1/r^2 relation is well known. As far citation goes those details ate mentioned in the links I provided had you bothered to read them but when you respond in less than 5 minutes after posting them claiming zero relevance I know you didn't even bother looking at them

[Moontanman]

4 minutes ago, Mordred said:

Funny how you made previous assertions that there is no risk due to radiation for the last couple of pages with others pointing out those errors yet you seem to think I'm incorrect for correcting you. 

I never said there is no risk, I am promoting risk mitigation, I say the risk can be mitigated. 

Can you or can you not back up your assertions about the EMP or the 100 megaton bomb needing to be detonated in the atmosphere or that the radiation from a nuke used to prevent an asteroid impact will be worse than the impact of the asteroid? 

Edited May 25 by Moontanman

[Mordred]

Yeah and I agreed with that 2 pages ago. Provided you can quarantee zero reentry.

[Moontanman]

2 minutes ago, Mordred said:

Yeah and I agreed with that 2 pages ago. Provided you can quarantee zero reentry.

I do not say that zero reentry is necessary or even possible. 

Can you provide a citation or not? 

Edited May 25 by Moontanman

[Mordred]

On 5/24/2024 at 12:13 PM, Mordred said:

Here this will help. This paper discusses the application of nuclear devices vs asteroids

https://ntrs.nasa.gov/api/citations/20205008370/downloads/Nuclear_Devices_for_Planetary_Defense_ASCEND_2020_FINAL_2020-10-02.pdf

The idea is feasible but has its own realm of problems. The paper mentions a few of them including political issues.

 

Here recall this study ???? Did you even bother looking at it ?

Citations have been provided try reading them

[Moontanman]

3 minutes ago, Mordred said:

Here recall this study ???? Did you even bother looking at it ?

Citations have been provided try reading them

Please show the paragraphs that support your assertions, its why we have the quote feature, I read it I don't see them. 

Mordred, I'm not asking you to do anything more than I or anyone else would have to do if called out on such an assertion. You made a claim that a nuke detonated close than the moon would result in a destructive EMP on the earth, you asserted a nuke wouldn't be effective unless it was detonated inside the atmosphere and suggested a 100 megaton nuke. 

Please provide a citation for these things!

Edited May 25 by Moontanman

[Mordred]

28 minutes ago, Moontanman said:

Please show the paragraphs that support your assertions, its why we have the quote feature, I read it I don't see them. 

Mordred, I'm not asking you to do anything more than I or anyone else would have to do if called out on such an assertion. You made a claim that a nuke detonated close than the moon would result in a destructive EMP on the earth, you asserted a nuke wouldn't be effective unless it was detonated inside the atmosphere and suggested a 100 megaton nuke. 

Please provide a citation for these things!

Do you not understand that most of the destructive force from a Nuke is the result of superheating the atmosphere to generate the shock waves ? 

Is that something you do not understand with regards to how a nuclear explosion  works ?

Do you honestly require a citation for something as obvious as that ?

Well here you go

https://www.deepspace.ucsb.edu/wp-content/uploads/2013/01/Effects-of-Nuclear-Weapons-1977-3rd-edition-complete.pdf

 

As for quoting the section read the introduction.

There is tons of material regarding EMP let's start here

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

This includes the Starfish test

It certainly highlights the difference between atmospheric explosions vs one in space.

 

Edited May 25 by Mordred

[Moontanman]

15 minutes ago, Mordred said:

Do you not understand that most of the destructive force from a Nuke is the result of superheating the atmosphere to generate the shock waves ? 

Is that something you do not understand with regards to how a nuclear explosion  works ?

Do you honestly require a citation for something as obvious as that ?

Well here you go

https://www.deepspace.ucsb.edu/wp-content/uploads/2013/01/Effects-of-Nuclear-Weapons-1977-3rd-edition-complete.pdf

I understand exactly how a nuke works, evidently even reading it in this article it remains unknown to you. 

15 minutes ago, Mordred said:

 

As for quoting the section read the introduction.

There is tons of material regarding EMP let's start here

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

This includes the Starfish test

 

No place in that article dose it say a nuke detonated anyplace inside the moons orbit will EMP the Earth. In fact it only mentions EMP up to 300 miles or so, not 250,000 miles so do you have a citation to support your assertions or not! 

[Mordred]

You can do math correct ? You do understand you can calculate it yourself. You won't find any paper that specifically describes what can obviously be calculated.

[Moontanman]

12 minutes ago, Mordred said:

You can do math correct ? You do understand you can calculate it yourself. You won't find any paper that specifically describes what can obviously be calculated.

I'm going to assume your assertions around the detonation of a nuke in space compared to the earth is just us talking past each other. I know the effect is not as great in space as it is on the ground but that doesn't mean it won't work... 

But your assertion that a nuke would produce an EMP all the way out to the moons orbit needs to be supported or you need to simply admit you yanked it from where the sun don't shine and we can move on. 

 

[Mordred]

Fine whatever you wish to believe try starting with 10^20 joules /s for radiated power from a 1.4 megaton blast then multiply that by whatever megaton value you think will be effective on said asteroid. Then recognize that you won't get much Compton scatterings to prevent those gamma rays from reaching Earths atmosphere and simply use the 1/r^2 relation for a spherically symmetric burst. 

I'm done arguing with you

[Moontanman]

4 minutes ago, Mordred said:

Fine whatever you wish to believe try starting with 10^20 joules /s for radiated power from a 1.4 megaton blast then multiply that by whatever megaton value you think will be effective on said asteroid. Then recognize that you won't get much Compton scatterings to prevent those gamma rays from reaching Earths atmosphere and simply use the 1/r^2 relation for a spherically symmetric burst. 

I'm done arguing with you

You have no argument until you provide a citation for your assertions!

[Mordred]

As stated citations were provided you simply had to look through them many of them included related links if you can't do math involving simple 1/r^2 relation that isn't my problem. You could have easily taked to power generated from  the 1.4 megaton blast and assumed 100 percent efficiency multiplied that your new megaton value assuming linear relation and calculated that gamma rays will still hit Earths atmosphere even if detonated at the distance of the moons orbit..

Back of the envelope Calc would give roughly 800 joules/sec for a 100 megaton blast. 

Granted that's an extremely rough calc with several assumptions ie no directivity reflecting from the asteroid toward Earth. I plucked the 10^20 value from related research papers directly detailing Starfish explosion 

 

Edited May 25 by Mordred

[Airbrush]

On 5/24/2024 at 10:12 AM, dimreepr said:

ICBM's aren't designed to explode in space, let alone escape from the gravity well.

It's not as simple as nukes are the ultimate destructive power, therefore I'm protected if I unleash them.

It's like saying "rat poison, will save humanity"...

You will need rockets that are designed to escape earth.  What will happen to ANY asteroid composed of anything, metal, rock, ice, rubble pile, cotton candy, or all those combined, when you explode a nuke at the correct distance from the asteroid?  There will be an intense pulse of heat for a fraction of a second.  What will that do?  It will melt, blister, fuse, cause outgassing, and explode volatiles, amounting to thousands of tiny rockets pushing in the same direction.  This will push the pile a tiny bit without breaking it up.  If you have a few hundred of these explosions, to make sure you have enough, you can fine tune for maximum course change.  This is way cheaper and faster to accomplish, than gravity tractors.  We have thousands of nukes.  We just need the technology to deliver them into the path of the asteroid.

Edited May 26 by Airbrush

[zapatos]

2 minutes ago, Airbrush said:

This is way cheaper and faster to accomplish, than gravity tractors.

How much is the relative cost compared to a gravity tractor?

[Airbrush]

7 minutes ago, zapatos said:

How much is the relative cost compared to a gravity tractor?

What is cheaper, to send a very massive object far away, with enough fuel for extreme, 180 degree, course changes, and enough fuel to keep pushing the tractor away from the object, and is massive enough to have an effect, OR to send a series of low-mass rockets, each with a single nuke and just enough fuel to accelerate to a very high speed to meet the asteroid as far away as possible?  Having many small missions acts as a fail-safe.  Having many gravity tractor seems much more expensive.  Mission accomplished by nukes years before a gravity tractor even gets started.

Edited May 26 by Airbrush

[zapatos]

1 minute ago, Airbrush said:

What is cheaper, to send a very massive object far away, with enough fuel for extreme, 180 degree, course changes, and enough fuel to keep pushing the tractor away from the object, and is massive enough to have an effect, OR to send a series of low-mass rockets, each with a nuke and just enough fuel to accelerate to a very high speed to meet the asteroid as far away as possible?

I don't know. You made the claim, that is why I was asking. I assume that either method is incredibly complex which means there are probably thousands of factors that must be addressed, all costing time and money. I couldn't possibly guess which method would cost more without any details of all those issues. I wouldn't even want to assume you need a "180 degree course change". Frankly I'd be shocked if we launched directly toward the asteroid in a straight line.

[Mordred]

You don't need a 180 degree course correction the further away you can induce a course correction the smaller the angle of change will be required.

 Nukes are fine far enough away how far that is will depend on how early you can spot the asteroid and how soon can you transport whatever correction method you use.

Every method requires fuel for starters our nukes are not designed for space. So you will need some craft simply to get the nukes to location.

I fail to understand why others cannot understand that simple fact.  You need a spacecraft to deliver the nukes. So where is the difference between that and a gravity tractor ?

Secondly outgassing is useless if the asteroid is spinning. It doesn't matter if you use nukes to generate outgassing. If the asteroid has a spin outgassing won't do any good.

Spin makes zero difference nor does asteroid composition for the gravity tractor method.

That isn't true for using nukes.

Thirdly we already have the capability of gravity tractors all you need is a spacecraft with enough fuel and mass. We already have that. Simply have a fuel reserve in space. 

If you can get to the asteroid early enough a mere 1/2 a degree correction would suffice. Quite frankly simply slowing the asteroid down would also work without an angle change. 

Edited May 26 by Mordred

[dimreepr]

6 hours ago, Airbrush said:

You will need rockets that are designed to escape earth.  What will happen to ANY asteroid composed of anything, metal, rock, ice, rubble pile, cotton candy, or all those combined, when you explode a nuke at the correct distance from the asteroid?  There will be an intense pulse of heat for a fraction of a second.  What will that do?  It will melt, blister, fuse, cause outgassing, and explode volatiles, amounting to thousands of tiny rockets pushing in the same direction.  This will push the pile a tiny bit without breaking it up.  If you have a few hundred of these explosions, to make sure you have enough, you can fine tune for maximum course change.  This is way cheaper and faster to accomplish, than gravity tractors.  We have thousands of nukes.  We just need the technology to deliver them into the path of the asteroid.

You're assuming the awful power to destroy here on Earth, would be replicated out there in space; for a start, we wouldn't be able to hear the bang... 😉

What's the point of blindly shooting nukes at the problem, they can backfire in a much more devastating way than a lump of lead.

Like I said on page one, our best defence is to keep our eyes peeled bc if we don't see it in time, we could fire every nuke on the planet and have no more effect on it's progress, than a spider's web in your path.

[Airbrush]

9 hours ago, Mordred said:

...outgassing is useless if the asteroid is spinning. It doesn't matter if you use nukes to generate outgassing. If the asteroid has a spin outgassing won't do any good.

Spin makes zero difference nor does asteroid composition for the gravity tractor method.

That isn't true for using nukes.

Thirdly we already have the capability of gravity tractors all you need is a spacecraft with enough fuel and mass. We already have that. Simply have a fuel reserve in space. 

If you can get to the asteroid early enough a mere 1/2 a degree correction would suffice. Quite frankly simply slowing the asteroid down would also work without an angle change. 

Correct me if I'm wrong, but most, if not all, asteroids are spinning.  A single nuclear pulse will last a fraction of a second, so the outgassing will last only seconds.  So, I believe outgassing will push for only a second.  Am I wrong?

Gravity tractors are an indirect method while a series of nuclear explosions in its' path works directly, thus mission accomplished sooner.  That is interesting having fuel reserves in space to somehow dock with the gravity tractor(s).  That will take a lot more time than nukes, and we DON'T HAVE TIME.

[Mordred]

How do you plan to get the nukes to say the orbit near Mars in time without using spacecraft ? After all the goal is to reach the asteroid as quickly as possible. Relying on the drift method aka Voyager 1 and 2 would take a good 6 months unless you have a good fuel reserve to speed up the trip.

For that matter simply load up the craft cargo space with nukes.

So I ask once again what's the difference ? Regardless if nukes are are used or not  you still have to get to the asteroid in the first place.

If the asteroid is already spinning outgassing will increase the spin rate. It will also continue until the surface cools down to the background temperature. Thermal radiation being part of the outgassing. 

Edited May 26 by Mordred

[zapatos]

33 minutes ago, Airbrush said:

That will take a lot more time than nukes, and we DON'T HAVE TIME.

Why don't we have time? Is there some asteroid we're about to collide with that I'm unaware of?

10 hours ago, Mordred said:

 Nukes are fine far enough away how far that is will depend on how early you can spot the asteroid and how soon can you transport whatever correction method you use.

 

This brings up a major concern of mine; how far away is safe enough to use nukes? 

Despite the talk of 'fine tuning' the use of nukes in this thread, I don't believe the words 'fine tuning' and 'nuclear weapons' go together. With a gravity tractor you have a pretty good idea how the asteroid will move, and it will all move in the same direction. If you use a nuclear weapon I feel like you run the risk of pieces of the asteroid moving in unanticipated ways. Perhaps if far enough away the risk is low enough, but if a gravity tractor would work, why introduce the risk of breaking the asteroid apart?

[Mordred]

How far away for nukes to be a safe option depends on megatons needed.

The back of the envelope calculation I did earlier showed that a 100 megaton nuke can still have EMP cause Compton scattering in our upper ionsphere from detonation at the moons orbit. Though from that distance it's minor in effect 

The EMP itself would be low enough not to cause electronic damage As  well.  

Now is a 100 megaton nuke excessive. Well hard to say we wouldn't be sending nukes unless the asteroid is large enough for an extinction level event. 

Edited May 26 by Mordred

[Moontanman]

2 minutes ago, Mordred said:

How far away for nukes to be a safe option depends on megatons needed.

The back of the envelope calculation I did earlier showed that a 100 megaton nuke can still have EMP cause Compton scattering in our upper ionsphere from detonation at the moons orbit. Though from that distance it's minor in effect 

The EMP itself would be low enough not to cause electronic damage As  well.  

Why would such a  warhead be used as an example here? Who has 100 megaton warheads? Who is capable of delivering a 100 megaton warhead? Why is the orbit of the moon being used as an limit? If all we would get is a minor effect why bring this up at all? This example is nothing but fear mongering, if you wait until an object is within the orbit of the moon you are up the creek, such an object is just hours, possibly minutes from impact at that point, do the math!

Why keep using these exaggerated examples instead of realistic scenarios? 

We need to plan ahead, get the infrastructure in pace before the threat looms over us but until that infrastructure is in place the easiest and fastest method should be used. Nuclear warheads delivered to the target via existing technology as far from us as possible would seem to be the best option we currently have. 

An asteroid impact is a serious event quite possibly apocalyptic anything other than our best efforts is suicide. Exaggerating the danger of nuclear technology does not serve us.