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New Best Way To Nuke a Short-Notice Asteroid
doug141 writes "A scientist proposes the best way to deal with an asteroid on short notice is to hit it with an impactor, followed by a nuke in the crater. From the article: 'Bong Wie, director of the Asteroid Deflection Research Center at Iowa State University, described the system his team is developing to attendees at the International Space Development Conference in La Jolla, Calif., on May 23. The annual National Space Society gathering attracted hundreds from the space industry around the world.
An anti-asteroid spacecraft would deliver a nuclear warhead to destroy an incoming threat before it could reach Earth, Wie said. The two-section spacecraft would consist of a kinetic energy impactor that would separate before arrival and blast a crater in the asteroid. The other half of the spacecraft would carry the nuclear weapon, which would then explode inside the crater after the vehicle impacted.'"
...his name is the sound his plan would make.
Bong Wie!
If you have the time for it, sure.
As the article says,
A nuclear weapon is the only thing that would work against an asteroid on short notice, Wie added. Other systems designed to divert an asteroid such as tugboats, gravity tractors, solar sails and mass drivers would require 10 or 20 years of advance notice.
It's not really possible to put big rocket motors on an asteroid and push it out of the way, as transporting enough fuel to the asteroid would be unbelievably expensive and likely infeasible with current technology.
Don't asteroids usually spin? If you blast a crater on one side, then you have some serious aiming to do to hit the crater?
Pack your bags kids! We're going to the moon!
because it's less expensive than rebuild a city?
It's not DESTROYING the incoming asteroid, it's breaking it up into smaller pieces and changing their trajectory. The point isn't to get the asteroid to miss us entirely, it's to make it not hit us all at once in one spot.
Small impacts would probably be pretty devastating for those that survive the atmosphere(think early impacts from Armageddon, etc) but at least it wouldn't cause a near-extinction of all life as a giant single impact could.
If the only way you can accept an assertion is by faith, then you are conceding that it can't be taken on its own merits
If we're facing a potential wipe-out of several major coastal cities, I'm hoping we would get some leeway on expenses.
Probably not though. :(
I'm sure we would still be fighting over who would pay for it, or some other political bullshit when it hit and killed us all.
Nuke it from orbit. It's the only way to be sure.
The Tao of math: The numbers you can count are not the real numbers.
What, you think someone smart enough to design a mission to intercept an asteroid with an impactor and hit that crater with a nuke wouldn't know to take the spin into account?
All this study was doing is working out whether the idea would work, not designing a complete mission profile for a specific asteroid.
But if we fired off two or three hundred nukes we can claim those as part of the disarming campaign, test them in live fire conditions, increase the exposure of space travel to people, and watch a bunch of real big light shows.
that is like 5 wins.
i thought once I was found, but it was only a dream.
Yes, but by breaking it into smaller chunks you are increasing the surface area of the impactor. Its mass obviously stays the same, so the surface area/mass ratio changes in your favour, which means more of the asteroid will get burned up in the atmosphere before hitting the Earth's surface. Of course it depends just how many bits you can smash it into as to whether or not this will be worthwhile.
Try it with ice cubes - fill two identical ice-cream tubs with water and freeze them. Smash one into bits (you don't need a nuclear warhead for this, but if you decide to use one please post a video on youtube) and put all the bits in a tray. Put the intact ice-lump onto a second tray and leave them side-by-side in the sun. See which one completely melts away first. Same amount of water, different mass/surface area ratios.
Nonsense. You'd just use the asteroid *itself* as fuel.
That's what the nuke does. The asteroid provides fuel (as in mass), and the nuke provides the energy.
Ezekiel 23:20
Letting it wipe out all life completely is the cheapest option at all - you don't spend a cent on rebuilding anything. :-)
Ezekiel 23:20
It's this thing called physics and specifically, astrophysics. You break these roids up into smaller pieces. The gravity of nearby planets and the sun would have a far more drastic effect on the smaller pieces as well as the energy from the explosion modifying the trajectory of the pieces.
I believe we're quite capable of telling the composition from remote observation and adjusting the plan accordingly. Also, some M-type asteroids (such as 16 Psyche, to name the most notorious example) do have significant quantities of iron, but I don't think that the majority of even the metallic M-type asteroids are solid iron. "High likelihood" is really an exaggeration.
Ezekiel 23:20
1998 QE2 will be about 3 Million miles away. I think we're pretty safe, no Nukes needed. =)
Wouldn't that make for a good test case though? I'd hope our first attempt at deflecting an asteroid isn't our one shot at survival. With it being so far away you could do a test on it and gather some valuable data.
I still prefer the odds on the broken up asteroid than the guaranteed end of human life full asteroid.
In addition it could be that many of the pieces will miss us anyway. The relative speed of the asteroid to earth could be as high as 70km/s, so if we hit it with 24 hours to go, that's 86400 seconds for each piece to shear away from us from a distance of 6 million km. We only need to change the asteroid piece trajectory slightly to make it miss the Earth entirely. Indeed it may be prudent to have a second warhead to explode after the first one to give the pieces more momentum away from the line of impact (we'd need around 100m/s, that's a lot of momentum to be giving to potentially massive lumps of rocky iron).
Actually if you break a large object into many small objects the pieces still have the same total kinetic energy.
It isn't the kinetic energy in space that's the problem. The problem is the kinetic energy at point of impact with the earth's surface.
If you spread that same energy out over hundreds (or perhaps thousands) of miles instead of one small impact crater, there is a very real qualatative difference. Not to mention the fact that the more surface area per mass an object has, the more of it will burn up in the atmosphere (further disspating the kinetic energy it had in space). Small objects tend to burn up completely.
Think about it this way: Would your property fare better in a hailstorm with thousands of pea-sized hailstones hitting your yard, or just one large hailstone with the same total mass?
I guess it will heavily depend on the asteroid.
Most certainly. No objection here.
Remember that a nuclear explosion is not that big. Without an atmospheric shock wave by suddenly heated air and with an asteroid not that scared about radioactivity, for many asteroids a nuclear bomb might have hardly any effect.
I'd disagree here. With a moderately underground burst, a substantial mass of the asteroid (compared to the mass of the nuke - not compared to the mass of the asteroid, of course!) gets vaporized. Please remember that this is the mode in which a nuke airburst creates a fireball: The air is heated into incandescence by an extreme flux of X-ray radiation. In solid matter, the exponential falloff of the X-rays happens over a smaller distance, but you still evaporate a lot.
If you do it on the surface or a few meters underground, you'll probably waste a lot of the energy. You'll get a lot of high temperature plasma, but the mass will be still quite low. What you should be aiming for (pun intended :-)) is a detonation depth sufficient to create a substantial mass of solid ejecta propelled by the explosion in (mostly) one direction such that their speed won't exceed some reasonble value (between 10-50 m/s?). Remember; you're aiming for maximum impulse, not for a high-speed jet. The remaining mass of the asteroid will receive the same impulse in the opposite direction.
If it has an effect it might disperse it a bit but garvity might still keep it together
The escape velocity of any small asteroid is minimal. You could jump with just your legs off of a 20km body and get lost in space just fine.
Ezekiel 23:20
That is true, but it really doesn't matter all that much if 1.0e9 tons hit you in the form of a few large fragments or a million small ones.
Firing birdshot, buckshot and slugs has exactly the same effect on the target?
You are aware that our planet is continuously peppered by space debris, amounting to something like 10000 to 1000000 tonnes per year?
Seen any nuclear winters lately as a result of all those impacts? Or those "toxic nitrogen oxides from the atmosphere heating" you're talking about?
There's an ocean of air above our heads, thousands of kilometers deep, perfectly capable of absorbing all of the impact from the smaller objects - be it kinetic or chemical.
The big objects are a problem cause they make it through those thousands of kilometers largely intact.
Just like with birdshot.
Stand far away, and it won't even scratch the target.
Fire a slug of the same mass, from the same distance and with the same load, and it will go right through the target.
Mit der Dummheit kämpfen Götter selbst vergebens
What about when it's the size of a small city?
I believe the official Protocol involves bending over and kissing your ass goodbye
---Saying gnome 3 is better than windows 8 not so much a compliment as it is damning with light praise.
Build a triangular shaped ship and just blast the asteroids into smaller chunks, then smaller pieces and then finally destroy them altogether.
Never argue with a man carrying a water buffalo
Once again, this is for a short-notice event. Landing is hard, it takes a lot of energy. Crashing is easy, sometimes it happens when you're trying to land. Better to plan to crash.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Last month, the annual Planetary Defense Conference took place, this time in Flagstaff, Arizona (down the road from Meteor Crater). If you are interested in this topic, you really should take a look at the incredible video archive which has ALL of the presentations -- like 23 hours of them. Seriously, if you really want to dive deep into this subject, imagine me GRABBING YOUR SHOULDERS AND SHAKING YOU and saying loudly right into your face "watch these videos!"
Here is the conference webpage:
http://www.iaaconferences.org/pdc2013/
And here is the program, useful for navigating the video archive below:
http://iaaweb.org/iaa/Scientific%20Activity/pdc2013program.pdf
But you really want to go to the videos. Here is the complete archive:
http://www.livestream.com/pdc2013/folder
Particularly germane to the discussion here, check out this video which includes two presentations:
http://www.livestream.com/pdc2013/video?clipId=pla_48629586-65d2-44c3-a1f3-57c0c259d526
At the 1h21m point:
Overview of Collisional-Threat Mitigation Activities at Lawrence Livermore National Laboratory
Paul Miller
(very dry delivery, but very interesting review of nuclear weapon solutions)
At the 1h42m40s point:
GPU Accelerated 3-D Modeling and Simulation of a Blended Kinetic Impact and Nuclear Subsurface Explosion
Brian Kaplinger
(new PhD, on the same team as Dr. Wie, the author mention in the post that leads this thread).
These guys have thought about these problems far harder than you have. You might benefit from listening to them for 20 minutes.
Or, you know, just skip this and resume your underinformed opinionating :)
One simple rule for its versus it's