Asteroid Destruction Sim Using Super Computer

[Mike DiCenso]

I found this video of the Sandista National Laboratories' simulation of the destruction of asteroid Golevka. The basic assumption is that a 10 megaton nuclear device is planted in the center of the asteroid, and then dedonated to see what would happen.


http://www.youtube.com/watch?v=e4HCTcQ-IWA


The asteroid in the sim is a real asteroid, choosen because it's properties are fairly well understood. The Sandista National Laboratories' image and description on the asteroid and the simulation:

http://www.sandia.gov/ASC/library/libra ... eroid.html

The dimensions given are rather interesting as well as the crack propgation and break up of the 500 x 600 x 700 meter asteroid. It's also a reminder of how overly simplistic our calculation models are for much of the versus debate when it comes to things like this.
-Mike

[GStone]

The htm link image makes me think of a brain scan. The video was cool. When it was breaking apart, it looked like liquid metal.

[Mike DiCenso]

Still the mechanics of the explosions effects is rather interesting. It looks as though the asteroid's center was vaporized into a nearly spherical hollow spheroid, and then the rest of the asteroid is shattered. Now compared the effects here to the results you might get on Wong's asteroid calculator, and note the disparity between them. A 10 megaton nuke shattered a 700 meter wide asteroid, whereas according to his calculator (assuming igneous rock, of course) that all you need is 343 kilotons. A factor 29 in difference!

I would say that this allows for a new reassement of firepower at least some parts of the versus debate.
-Mike

[Mr. Oragahn]

Still the mechanics of the explosions effects is rather interesting. It looks as though the asteroid's center was vaporized into a nearly spherical hollow spheroid, and then the rest of the asteroid is shattered. Now compared the effects here to the results you might get on Wong's asteroid calculator, and note the disparity between them. A 10 megaton nuke shattered a 700 meter wide asteroid, whereas according to his calculator (assuming igneous rock, of course) that all you need is 343 kilotons. A factor 29 in difference!

I would say that this allows for a new reassement of firepower at least some parts of the versus debate.
-Mike

There may be some points to revise, but let's also consider that the simulation shows a reaction that takes out a significant amount of the asteroid.

Slightly more than a half of the asteroid seems to be vaporized, while the surrounding layer of rock is definitively compressed and cracked.
What about the interlayer that should be somehow melted btw?

After all 219 kilotons is still a huge amount of power, and 600 meters is still an extremely short radius.

That 10 MT bomb looks a bit like an overkill, and the final debris It clearly turns the asteroid into small enough debris which Earth's atmosphere would have no issue to deal with.

For example, assuming that this asteroid is roughly 600 meters wide (average value between both high and low end dimensions), then the spherical void has a diameter of 230 m (approx.).

Check out Wong's table then, and you'll see that he may even be actually overgenerous in his figures, where vaporization yields for hard granite and nickel-iron are respectively 46.8 MT and 91.1 MT.

Thus, much more than what would seem to be necessary to actually instantly vaporize a spherical mass of rock with a charge detonating in its center.

And if the core that disappears is only ruled out by the computer as it is melted, then 10 megatons is surprisingly well within both hard granite's and nickel-iron's figures, respectively 9.4 MT and 15.3 MT.

So let's wait a bit and see what happens next.

[Nonamer]

Still the mechanics of the explosions effects is rather interesting. It looks as though the asteroid's center was vaporized into a nearly spherical hollow spheroid, and then the rest of the asteroid is shattered. Now compared the effects here to the results you might get on Wong's asteroid calculator, and note the disparity between them. A 10 megaton nuke shattered a 700 meter wide asteroid, whereas according to his calculator (assuming igneous rock, of course) that all you need is 343 kilotons. A factor 29 in difference!

I would say that this allows for a new reassement of firepower at least some parts of the versus debate.
-Mike

I can hear the spin already.

[Mike DiCenso]

Mr. Oragahn wrote:

That 10 MT bomb looks a bit like an overkill, and the final debris It clearly turns the asteroid into small enough debris which Earth's atmosphere would have no issue to deal with.

That is not the case with the simulation's conclusions for Golevka's destruction:

http://www.usatoday.com/tech/science/sp ... roid_x.htm

In addition to avoiding the need to drill into the asteroid to plant the explosive, the smaller yeild nukes avoid the risk of leaving significant debris, which is what we see in the simulation. Lots of chunks of debris that would survive entry into Earth's atmosphere, and cause widespread devastation over the globe.

For example, assuming that this asteroid is roughly 600 meters wide (average value between both high and low end dimensions), then the spherical void has a diameter of 230 m (approx.).

There are some problems here, especially since according to some sources, Golveka has an overall average density of 2.5 tonnes per meter cubed. This means neither hard granite, nor solid iron are applicable here.

Check out Wong's table then, and you'll see that he may even be actually overgenerous in his figures, where vaporization yields for hard granite and nickel-iron are respectively 46.8 MT and 91.1 MT.

Thus, much more than what would seem to be necessary to actually instantly vaporize a spherical mass of rock with a charge detonating in its center.

And if the core that disappears is only ruled out by the computer as it is melted, then 10 megatons is surprisingly well within both hard granite's and nickel-iron's figures, respectively 9.4 MT and 15.3 MT.

So let's wait a bit and see what happens next.

Look more closely at the video, particularly in the highest resolution simulation; the core does not appear to melt or necessarily even vaporize significantly, but shatters and expands outward like much of the rest of the asteroid.
-Mike

[Mike DiCenso]

Still the mechanics of the explosions effects is rather interesting. It looks as though the asteroid's center was vaporized into a nearly spherical hollow spheroid, and then the rest of the asteroid is shattered. Now compared the effects here to the results you might get on Wong's asteroid calculator, and note the disparity between them. A 10 megaton nuke shattered a 700 meter wide asteroid, whereas according to his calculator (assuming igneous rock, of course) that all you need is 343 kilotons. A factor 29 in difference!

I would say that this allows for a new reassement of firepower at least some parts of the versus debate.
-Mike

I can here the spin already.

Well, sure, it would potentially up the Slave-I firepower. However on the flip side of the coin, it would also significantly up the lower-end firepower Trek examples, such as "The Pegasus" [TNG7] as well.

[Mr. Oragahn]

That is not the case with the simulation's conclusions for Golevka's destruction:

http://www.usatoday.com/tech/science/sp ... roid_x.htm

In addition to avoiding the need to drill into the asteroid to plant the explosive, the smaller yeild nukes avoid the risk of leaving significant debris, which is what we see in the simulation. Lots of chunks of debris that would survive entry into Earth's atmosphere, and cause widespread devastation over the globe.

The chunks are definitively too big, if they actually remain chunks. However, unless I missed it, the conclusion don't say if the chunks on the video still are assembled.
I was under the impression that the billions of nodes used for the sim didn't not necessarily show that they were still bonded to each other. They may just look assembled because they're micro fragmented, yet still close to each other.
In the case that they're still massive chunks, then it would be horrible. Some of them would be like way more than 100 meters large, 5 times more than the estimation diameter of the asteroid responsible of that 20 MT airbust at Tunguska.
That sucks. Big times.

There are some problems here, especially since according to some sources, Golveka has an overall average density of 2.5 tonnes per meter cubed. This means neither hard granite, nor solid iron are applicable here.

That's 2.5 g/ cm³, right? We're slightly above carbon. Add other denser materials, and that's it. Some asteroids have a mixture of nickel-iron and less dense materials.

Check out Wong's table then, and you'll see that he may even be actually overgenerous in his figures, where vaporization yields for hard granite and nickel-iron are respectively 46.8 MT and 91.1 MT.

Thus, much more than what would seem to be necessary to actually instantly vaporize a spherical mass of rock with a charge detonating in its center.

And if the core that disappears is only ruled out by the computer as it is melted, then 10 megatons is surprisingly well within both hard granite's and nickel-iron's figures, respectively 9.4 MT and 15.3 MT.

So let's wait a bit and see what happens next.

Look more closely at the video, particularly in the highest resolution simulation; the core does not appear to melt or necessarily even vaporize significantly, but shatters and expands outward like much of the rest of the asteroid.
-Mike

I really don't get that impression. It's all up to how fast heat can be transfered before the material cracks. At the core, I believe it's too densely packed for the material to crack and expand outwards, out of the vaporization range, before it's actually caught in that range.
It looks just impossible. How couldn't a 10 megaton nuke not vaporize, nor even melt the natural materials located in at least a 100 meters radius from the nuke itself?
The hole widens, but its edge remains to distinctive, clear cut; too precise, too clean.

[Mike DiCenso]

That is not the case with the simulation's conclusions for Golevka's destruction:

http://www.usatoday.com/tech/science/sp ... roid_x.htm

In addition to avoiding the need to drill into the asteroid to plant the explosive, the smaller yeild nukes avoid the risk of leaving significant debris, which is what we see in the simulation. Lots of chunks of debris that would survive entry into Earth's atmosphere, and cause widespread devastation over the globe.

Mr. Oragahn wrote:

The chunks are definitively too big, if they actually remain chunks. However, unless I missed it, the conclusion don't say if the chunks on the video still are assembled.
I was under the impression that the billions of nodes used for the sim didn't not necessarily show that they were still bonded to each other. They may just look assembled because they're micro fragmented, yet still close to each other.
In the case that they're still massive chunks, then it would be horrible. Some of them would be like way more than 100 meters large, 5 times more than the estimation diameter of the asteroid responsible of that 20 MT airbust at Tunguska.
That sucks. Big times.

At 1-meter resolution, we still have chunks of significantly intact (read no obvious fracture) rock blasted away from the site of the original asteroid. It could be that the material will continue to break up into smaller pieces, but it will not be uniformly so. In any case, the conclusions of the simulation was that small nukes to nudge and deflect, but not a big one to blow up or "vaporize" such an asteroid is apparently the best policy.

There are some problems here, especially since according to some sources, Golveka has an overall average density of 2.5 tonnes per meter cubed. This means neither hard granite, nor solid iron are applicable here.

That's 2.5 g/ cm³, right? We're slightly above carbon. Add other denser materials, and that's it. Some asteroids have a mixture of nickel-iron and less dense materials.

Golevka has a mean overall density of 2.7 g/cm^3, which is about right for most S-type asteroids (2.5 g per cm cubed is also about the same as Earth's crust, btw). The much larger S-type asteroid 433 Eros, for example, has a mean density of around 2.4 g/cm^3. There may be iron mixed in, but there is also quite a bit of silicates in there as well, and we know now thanks to NEAR's study of 433 Eros that at least some asteroids are likely loose collections of rubble.

I really don't get that impression. It's all up to how fast heat can be transfered before the material cracks. At the core, I believe it's too densely packed for the material to crack and expand outwards, out of the vaporization range, before it's actually caught in that range.
It looks just impossible. How couldn't a 10 megaton nuke not vaporize, nor even melt the natural materials located in at least a 100 meters radius from the nuke itself?
The hole widens, but its edge remains to distinctive, clear cut; too precise, too clean.

The coloration bands are a measure of the velocities of the asteroid's material as it is broken up and flung outward by the force of the explosion. Unfortunately we don't have a scalar of how heated the material is, but it would appear that at least the outer portion of the brownish-colored "core" is still solid or at least not vaporized, and the material is breaking up much as the other outer material is.
-Mike

[Mr. Oragahn]

The brown outersheel of the core, I can agree that around this zone, the asteroid is solid, up to the surface.
The rest, it has to be vaporized. Nukes have been vaporizing all sorts of stuff, from concrete to steel cables IIRC, even outside of the fireball's radius, due to thermal conductivity.
That's why I think that if you seek fragmentation only, a 10 MT bomb may not be necessary, but as seen by the sim, even a 10 MT doesn't manage to break most of the asteroid down to 10 meters wide bits.
Now, the fragmentation figure Wong's calculator provies is for igeneous rock.

It would seem that the melt and vaporization are rather correct, but however inferior to what's necessary when it comes to fragmentation only, because apparently, or at least for the parameters they've entered, in order to achieve a throughout fragmentation to a majority of 10 meters wide chunks, you'll end vaporizing a huge load of the asteroid itself, by activating a warhead in the very core of the body.

What I know for sure is that I won't jump to conclusions so hastily, and nothing shows me that Wong's calculated figures regarding asteroid fusion or vaporization are inferior to what they should be.
It seems that only the fragmentation part is in dispute.

[Mike DiCenso]

Here's another image from the simulation showing a more "realistic" effect with the asteroid clearly breaking up into large fragments from the explosion:

Link truncated - JMS


As for the melt and vaporization on Wong's calculator, there are other flaws with that even, such as the use of elemental iron that make the whole thing a bit flawed, but the fragmentation issue is a rather interesting one as brought up by the Sandina National Laboratories' simulation.
-Mike

[Nonamer]

Please shorten up that link!

And it won't increase any calcs unless we see a total destruction of an asteroid, something that happens far less than claimed in SW.

On the other hand, there was an episode in ST:Voy where they were blowing up asteroids. I wonder if anyone had any info on that episode (forgot the title).

[Mr. Oragahn]

I agree, please shorten the link.

The picture tiself is extrmely interesting. If the luminosity is reliable, we see that in fact, only a moderate thickness of the asteroid's surface remains solid, while a large portion of the asteroid's inside is melted, which explains the compression, with in all logic the core being completely vaporized.

[Mike DiCenso]

Please shorten up that link!

And it won't increase any calcs unless we see a total destruction of an asteroid, something that happens far less than claimed in SW.

On the other hand, there was an episode in ST:Voy where they were blowing up asteroids. I wonder if anyone had any info on that episode (forgot the title).

Actually, you missed the point. It took a 10 megaton device planted in the center of the simulated Golevka asteroid to blow it apart. This is far different than overly simplistic models many Versus debators use, as well as the overly simple assumptions of the SDN asteroid calculator.

The melt and vaporization energies are another matter all together.

But anyway, I'am glad you brought up VOY's "Rise", as that episode's asteroid shattering (it was an artifical asteroid made in some part of two artifical alloys, plus natural oviline, and was not the natural nickel-iron asteroid that the crew had expected) benefits as the shattering energies may go up by an order of magnitude or so as result.
-Mike

[Mr. Oragahn]

Here's the Radar Observations and Physical Model of Asteroid 6489 Golevka (PDF).

If considered a sphere, the diameter would be 530 meters, more or less 30 meters.
It's an S-class asteroid (stony).