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HOW-TO: Asteroid -> Strategic Weapon
Beatlebum writes "A TEAM of British space scientists has devised a plan to nudge an asteroid out of its solar orbit and send it hurtling into the centre of a British Town. The story posted in the Electronic Telegraph describes how a few small atomic blasts could change a comet's trajectory enough to make it crash to any point on earth. The impact of even a small asteroid would make an ICBM look like a firecracker."
this is a way for the researchers to get a military size budget by pretending asteroids are weapons. the article says it takes 15 nukes to move an asteroid with the explosive power of 15 nukes. there is no point. asteroids are extremely rare.
This is actually very easy to postulate, but the actual implementation of this would wind up looking like a huge game of Pong. If two countries were trying to get this to hit each other, they would blast it back and forth, constantly changing the trajectory of the asteroid similar to the known universe's largest ping-pong ball with a catch, the asteroid could eventually explode and we'd all be in trouble.
Look on the bright side. India and Pakastan wouldn't be using it anytime soon on each other, unless they both want to go careening into the Indian Ocean.
Secret windows code
Clinton made me a Republican. Bush made me a Libertarian. Trump is making me question reality.
It's the new arms race! WWIII will be a billards game played out in space!
from even earlier, remember Star Blazers? Remember the Gammalons?
Remember Planet Bombs?
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
well, seeing as how England is an ISLAND, it's more likely that they'll hit some water nearby.
Big ol splash. Could possibly give Bath a Bath.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
well, if they did their presentation on power-point, maybe we need to be afraid. . .
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
slamming a comet into mars with enough water to be useful would also likely bring enough atmospheric dust to be a nuisance for a period of time longer than it would take for the water to sublime, and molecules to be blown out of the upper atmosphere by the solar wind.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
I assume these scientists were inspired by watching Babylon 5. Mass drivers can be fun!
The proposed mission puts 20 or so small nukes into independent orbits around the asteroid. I imagine the controlling processors would learn its exact mass profile pretty quickly. They also use a whole series of nudges to get it on target. The whole process takes a couple of years, so there no hurry.
The only real problem would be if the asteroid turned out not to be solid enough to deflect in one piece.
Read the article. The scenario envisaged is an unmanned launch disguised as a Mars or similar mission. This is "lost" and makes a rendezvous with the asteroid where it unloads 20 or so small nukes into orbits around the asteroid (ideally an otherwise unidentified one about 100m across). The nukes are used to alter the orbit of the asteroid, exploding when the sun is between Earth and the asteroid, leaving just one final course correction to be done in the final month of so before impact, shifting it from a near-miss to a collision.
In their simulations an average of 15 blasts was enough to hit a medium sized city.
Once the final blast is done, it could probably be nudged into a nearby ocean or something up to the last few days, but a hitherto unsuspecting opponent would probably not be able to launch a nuke beyond Earth orbit (an ICBM will not do) fast enough to do this themselves.
Budget, less than 100 billion $ for the first one, much less for subsequent ones.
Now, instead of "The Bomb" a rival country could be considered a threat if they have "The Asteroid".
The Mobile Suit Gundam anime series had the orbital breakaway state of Jion dropping asteroids on earth cities, and that came out back in the late 70's/80's.
Speaking of B5, MS Gundam also took a big O'Neil type colony, filled it with CO2, and turned it into a superlaser. Very cool, at least when it's safely ficticious.
Jon
All opinions expressed herein are my own, and not those of my employers, who are appalled.
but oh the collateral damage - Say London wants to take out ******, The Brits should at least expect some climatic changes to their island.
Think of MAD in terms of what makes people drive safely on the highways - it isn't traffic laws that prevent someone from bashing into you at 100 km/hr.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
Of course, with our luck, MS will bribe all the right people and send the meteor to San Jose. Good bye Sun, most of Cisco and Intel, Linus Torvalds, and a whole bunch of other threats to Microsoft's power.
ObJectBridge (GPL'd Java ODMG) needs volunteers.
Finding God in a Dog
It doesn't take a nuclear rocket scientist to know that this stuff is capable of destroying whole countries.
And it doesn't take a geologist to know that the world is flat, or a biologist to know that maggots spontaneously generate from rotting meat.
As for the former, the Castle Bravo test literally destroyed the island in question and left nothing but a huge crater in its place.
That island was somewhat smaller than North America.
-
I'm quite impressed with this work, not because it draws out a plan for using asteroids as weapons, but because it can offer a somewhat more compelling reason for governments to fund research into 'killer asteroids'.
Face it, if astronomers say that something's got a one-in-a-million chance of hitting us, or that it passes within 600,000 miles of Earth, it lacks a certain kick--it's just astronomy, and that isn't a top priority. However, if they successfully argue that the Other Guy(s) could use these things as weapons, the issue becomes one of national defense. National defense gets funded.
Of course, one has to make a good scientific case first. I'm waiting for an actual paper before deciding how plausible it actually is--though no matter what, it's still an interesting idea.
-W-
"Is it all journey, or is there landfall?"
-W-
Is it all journey, or is there landfall?
--Ellison & van Vogt, 'The Human Operators'
Since current theories regarding the mass die out of the dinosaurs seem to revolve around a collision of either a comet or asteroid with the Earth, one's got to wonder if these geniuses have ever heard of the term Mutually Assured Destruction.
Geez...
(Someone please tell me that this is an April Fool's joke that someone just found underneath a pile of magazines.)
--
CUR ALLOC 20195.....5804M
Well... At least this will solve the Middle East Conflict once and for all. No more whose is the holy city question to fight about.
Baker's Law: Misery no longer loves company. Nowadays it insists on it
http://www.sigsegv.cx/
Why asteroid. Kinetic harpoons which are a recent hit in some british sci fi will do nicely.
All you need is a high polar orbit platform. Minor orbit correction, and a delivery vehicle detaches and starts to deccelerate. After it has deccelerated enough it launches several properly shaped tungsten charges proteced by ceramics or composite material so that they can be slammed into the ground at proper speed without burning in the atmosphere. They hit the ground preheated to melting temperature and flying at several kilometers per second.
Precise when used versus stationary targets.
Deadly.
No fallout.
Very low maintenance costs once the platform launched. The platform if it is in polar orbit can hit any place on the globe within 24 hours. 12 platforms can cover the entire globe within the requirements of a tactical strike.
Yummy...
Baker's Law: Misery no longer loves company. Nowadays it insists on it
http://www.sigsegv.cx/
We have all seen Armageddon, I think. What would be the impact on the rest of us?
or...
"We will destroy your town with an Asteroid, unless you pay us...
ONE MILLION DOLLARS!!!"
Jethro
Quidquid latine dictum sit, altum viditur.
Is it me or is there one big mother of a middle man that can be cut out of the equation here?
Yeah, but think of the style points you would get...
the fact that asteroids aren't perfect spheres. In fact, they're pretty far from being ANY perfect shape. They're probably not of uniform density, either. Add to that the fact that it's probably rotating unevenly, and you have one hell of an unpredictable rock floating through the cosmos.
Finding the center of mass in an arbitrary asteroid and then finding a way to nuke the precise point on it's surface isn't going to be something you can calculate easily with a computer program; you're gonna need to go to the asteroid you pick, study it for a while and THEN experiment a little with changing it's trajectory. All this before you're ready to aim it at Earth and *maybe* hit your target.
I suspect the article linked to is meant to be read as tongue-in-cheek, just like the one a few weeks ago on using asteroids to change Earth's orbit when the sun starts expanding.
-Chris
...More Powerful than Otto Preminger...
And very importantly, you can destroy a nuke before it explodes, and it doesn't go off, you destroy an asteroid, well it may help some.
"instead of hitting Chicago you hit Paris - try apologizing for that one."
Mad Scientist: Sorry, France, but we've blown up Paris.
French: Oooh, that makes us sooo mad. Hmph.
Mad Scientist (blinks several times, waits)....
French: Hey, did that grove of trees we planted to signify our version of the prime meridian help you with your targeting?
Mad Scientist: Uhm, I think I hear Igor calling.
French (puffs on cigarette, drinks glass of wine, goes on with life)
Not representing or approved by my company or anybody else.
The only rational assumption can be that this is a trial run to ensure that they can land an asteroid *directly* on target next time, when they choose to wipe Slough off the face of this green and pleasant land.
++ Say to Elrond "Hello.".
Elrond says "No.". Elrond gives you some lunch.
I can here it now...Stu-pid! Stu-pid! Stu-pid! ... You get the point.
There ain't no way in bloody freakin' hell they can target this thing with enough accuracy to make it worth their while. One innocently slipped decimal place or one graduate student intern using the wrong unit of measure and the asteroid you intended for the Presidential Palace in Baghdad lands in the Knesset.
Code commentary is like sex.
If it's good, it's VERY good.
My office has been taken over by iPod people.
This does sound like a Bond villian scheme, specifically like Octopussy. I do think it bears pointing out the other advantage of this scheme. You use 15 small nukes to get the equivalent of 15 very large nukes. If you know this is coming you can covertly prepare to protect your government. Whilst, most US citizens would rather see their government severely disrupted, this may not be true for the rest of the world. (No, they'd all like to see the US government disrupted too.)
So long and thanks for all the fish . . . !!!
I think you're right. Also I think there's an error in the original story.
In most articles on the subject, the adjective "small" is not found anywhere near the quantifier "1 megaton"....
(megaton-class Nukes tend to be fusion hence expensive and big. "tactical" nukes which are smaller and lighter and pure fission or fission-boosted are in the 10-500 *Kilo*ton range).
--
I'd rather have a bottle in front of me than a frontal lobotomy
you have to rachet it up a bit.
So some scientist tried to scare the public into diverting more funds into their pet projects. The public said, "Ho-hum. More Chicken Littles proclaiming that the sky is falling." So the scientist try a publicity stunt.
"I know what we can do, Dr. Bubba. Let's do some math that very few of the people understand that'll show how we can use nukes to alter the path of an asteroid so that it'll blow up an insignificant little town. That'll scare the bejeesus out of 'em fer sure."
"But Dr. Dufus, we don't have the technology to target asteroids. Remember, if it were that easy, we could just deflect them when they got close enough to be noticed."
"Yeah, you're right. But remember, people are DUMB. They'll never notice if we put enough equations and other mathy stuff into the presentation. Then we could do this neat graphical thing where a space shuttle has to blow up because the nukes don't do their job right."
"You're right. Let's do it, Dufus."
Nothing to see here but some scientist who aren't getting their pet projects funded trying to scare up some support.
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
(Pardon my speculation as to the content of the article; at the present time it is inaccessible to me). Using nuclear weapons to guide asteroids and comets is an interesting idea, but the choice of using it for warmaking is odd. From a practical sense, the object would be far from "stealthy;" an intense X-ray source emmanating from a chunk of sky would almost certainly be detected, given our current capability, and it would tell us exactly where to look. We'd certainly wonder about that object coming towards us, especially when it changes course en route to Earth.
Any state with the technological savvy and nuclear arsenal to conduct such an activity would be able to dispose of its enemies in another fashion, and its enemies no doubt could dispose of the aggressor. (If not, then more conventional modes of attack could be used by the aggressor with greater precision, flexibility, and lower cost). Besides, the number of possible adversaries a target state would have that could conduct such a mission is very limited, so the target state would know full well who lofted a big snowball at them, and they would merely respond in kind prior to impact with whatever arsenal they had available. The only real use I can see for such a technology is to somehow coordinate it with a first-strike nuclear attack, with the big space rock knocking out hard targets such as underground command centers.
An alternative, peaceful use for such a technology would be to bring resources such as H2O to places we'd like to colonize. Slam a comet into the moon or Mars to bring water there, for example. Unlike trying to precisely control the descent of a chunk of ice onto Earth, a dicey game at best, one could instead direct the comet toward a different celestial body and have a much larger margin of error.
I'm reminded of an article I read on nuclear launch systems a while back. When the guys in the silo turn the key, the missiles launch, right?
Wrong. It sends launch codes to the missile, and those launch codes might say "go now," but they could also tell the missile to wait minutes, hours, days, years, even indefinitely. (The last would allow a single pod to launch them in the future, instead of the multiple pods required for the first launch command.)
The rationale is to provide a "second strike" capacity - the missiles will be launched when the enemy is attempting to rebuild the military base, etc. Evem if your launch crew is all dead, those missiles will launch.
An asteroid strike would be a very compelling second-strike weapon. Silos could be destroyed, blocked, disarmed, etc. But the asteroid-tweaking mission could be launched during the initial exchange and then it's out of reach until impact.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
The amount of available nuclear bombs is still large enough to destroy the Earth ~10,000 times. A single H-Bomb can destroy whole countries and make them uninhabitable for years.
H-Bombs are evil, but this is FUD. Nuclear weapons can make areas of land inhabitable, and will dramatically affect the land for years - but the odds of a nuclear conflict that actually reduced the earth to ashes are completely improbable. Cities are the only targets that nuclear weapons effectively destroy - that, and perhaps large dams (think three gorges and the hoover dam). There's some doubt there too. There's little military strategic value in blowing up land nobody lives on, after you've wiped out all the cities.
Contrast this with a large asteroid. The resulting firestorm would burn everything on the planet that -could- burn. Humans just wouldn't be extincted, but probably everything more complicated than inscects and small rodents. There's no radiation of course (unless the asteroid was a block of uranium, which I find unlikely). Even then.
Then there's biological and chemical weapons. A genetically engineered virus, with the right incubation time, could kill us all in a couple of weeks.
Again, FUD. Biological and Chemical weapons are a particular pet peeve of mine, and my government (Canada) is no exception to the rule here - it absolutely disgusts me that people would invest time and (MY) tax dollars in developing stockpiles of nerve gas and biological weapons that serve NO defensive purpose - they're only offensive. Chemical and biological weapons are possibly some of the worst, more horrible ways to die that we've come up with, but even then, they're not going to kill us all. They'll just kill everyone in cities and urban areas, with developed nations the hardest hit.
Contrast with Mr. Asteroid - a good impact will, in one fell swoop, probably take out a continent! A whole continent! Unimaginable energies!
Ah well.. the only thing that will wake people up is a small asteroid taking out a major center (preferably American, because that's the only country with the resources to do anything). :)
..don't panic
Nor does it take a nuclear rocket scientist to realize that blast and radiation damage don't scale linearly with megatonnage.
Yes, Tsar Bomba was 100MT. No, even the Russians didn't make it part of their arsenal, because it cost a bloody fortune to build, and didn't do much more damage than a 25MT bomb.
With 1960s-era guidance systems, you needed large bombs to ensure that you took out the target, because you couldn't be sure your bomb would hit the target to within $BIGNUM radius.
With 2000-era guidance systems, you can hit the target, and you therefore no longer need to dump anywhere near the same amount of explosive power onto the target to take it out.
The future of warfare is precision munitions. Even for hardened targets, a penetrating warhead and a conventional load (or for soft targets, a big-ass FAE - fuel-air-explosive) can be far more effective than either a tac-nuke (multi-kiloton) or big-ass nuke (multi-megaton) device.
The target's destroyed - the fact that there's no fallout issue with precision-guided conventional munitions is just one hell of a nice fringe benefit for your troops.
Nukes kick ass. But for the most part, they're obsolete except as a deterrent. They have a place in the arsenal, but the generals - from any nation - are aware that there are almost always better (cheaper and more effective) ways of accomplishing the mission.
If you want to worry about something, fear the rogue state that builds a basement nuke, or worse, chemical/biological weapons (e.g. the possibility that foot-and-mouth disease being a possible instance of bioterrorism or asymmetrical warfare). The nuclear arsenals of the superpowers are the least of your worries.
The first man that made 'er
Was an Engineer, of course
But then a bloody asteroid
Squished Godiva's horse?
The difference is that the rock leaves a lot less radiation I think. but I could be completely wrong...
//rdj
No one can understand the truth until he drinks of coffee's frothy goodness.
--Sheikh Abd-Al-Kadir, 1587
Ah ! You haven't read the article right.
It takes 15 1-megaton (read: SMALL) nukes to create an explosion equivalent to 15 H-bombs (read: BIIIIIIG).
No, silly. All you have to do is hit William Shatner on the head with a large rock so he loses his memory, falls in love with the Indian princess, and accidentally discovers the controls to the asteroid deflector. Sheesh. You people.
I am quite civilized, and I should be brought a beer immediately. -- Bruce Sterling
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crazy dynamite monkey
From the "Disperse Life" pages:
(An "inforb" is an orbit occupied by informational entities. A "biorb" is an orbit occupied by biological entities.)
The first biorb is likely to be around Earth growing out of the . It will grow Before growing far toward being heliocentric, the first biorb will need to begin the defense of Earth against celestial attacks.
Kinetic energy asteroidal weapons are the most likely technology to represent the greatest threat to Earth as a result of the growing solar biorb. Once asteroid mining begins in earnest, as it will once life becomes heliocentric, asteroids can be redirected via carefully planned celestial mechanics. Within a matter of decades, a malicious interest could send a swarm of tiny asteroids toward Earth at speeds comparable to that of the Swift Tuttle comet -- a popular candidate for global disaster scenarios. Since kinetic energy goes up as the square of velocity, the important thing is to find small asteroids with the right trajectories. This would most likely be carried out on the basis of a fairly complete atlas of the trajectories of small asteroids, searching for some large number of them that could be manipulated to converge on Earth with maximum relative velocity over a fairly narrow window of time.
The most economic defense will likely be the preemptive survey, cataloging and monitoring of all celestial objects (comets as well as asteroids) large enough to survive high speed passage through Earth's atmostphere with little loss due to ablation. This means the initial prospecting for asteroidal resources will be carried out by Earth shielding entities. It is difficult to second guess the technologies that would be available for this task so far in the future, but candidate technologies are already upon us and surveys are already being done.
Perhaps the most positive aspect of this situation is that when an asteroid is identified as a threat, it is also identified as a particularly attractive source of "fuel" for space transportation. Any asteroid that has a high velocity relative to Earth, or can be easily made to have such a velocity, and which has an orbit that can be made to come near Earth, can be used as reaction mass to navigate the inner solar system. Each time this is done, the threat represented by such asteroids diminishes. It's as though someone had discovered a way to burn nuclear fuel in jets without pollution. The bombs would get burned up due to economic demand.
Additional global threats to Earth are most likely decreased by removing technological civilization from its biosphere.
Seastead this.
While I'm not one of those enviro-nuts who worry about the 1 in 1e12 chance of a satellite's plutonium powercell exploding, I am somewhat leery of the science fiction premise that we'll get tons of new raw materials from the asteroid belt or moon.
The idea is simple: go to where the iron, nickle, cadmium, and other valuable minerals are, and ship them home. There's plenty of rocks up there.
The risks are high: you're guiding rocks of important sizes towards several billion sitting ducks. "Catching" the rock in Earth orbit is just a mite riskier than guiding a broken Mir into an uninhabited stretch of ocean.
[
So now I know why I was raised playing "Asteroids" and "Missle Command", I was unwittingly trying out to be the "Ender" of our generation.
- passion
How are you gentlemen.
All your small English town are belong to us.
Move all 'crumpet'.
For great justice.
This parody brought to by the SBAITGFGS - Society to Beat AYB Into the Ground (For Great Justice)
"Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased
...let me get this straight.
It would take 15 nuclear explosions to push a rock on to a collision course with Earth to create an explosion equivalent to 15 nuclear bombs.
Is it me or is there one big mother of a middle man that can be cut out of the equation here?
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Moderator's essentials
Why hairtrigger? This would work best to hurt an enemy state without being concerned about retaliation - it would look like an accident (or act of God, if you prefer).
sig fault
In order to prevent a meteor attack, raise chocobos until you have an ocean-going chocobo, and then summon Knights of the Round a few times!
-- @rjamestaylor on Ello
The Heavy Gear universe does this; 40 ton rods of Titanium, I believe. Point'em and drop'em.
Vintage computer games and RPG books available. Email me if you're interested.
Vintage computer games and RPG books available. Email me if you're interested.
Yes, but the CEP would still be smaller than the crater. :-)
Vintage computer games and RPG books available. Email me if you're interested.
6. Redmond
If you thought that the cold war with atomic weapons would leave the Earth cold and desolate, try sending an asteroid of any size to impact. According to the people they don't let out too often, a water hit is worse than a land hit as well.
Just something to think about before people get too happy about this as a defensive/offensive device.
DanH
Cav Pilot's Reference Page
Cav Pilot's Reference Page
UNIX - Not just for Vestal Virgins anymore
ABC-weapons are already pretty good at killing lots of people, and they are easy to get. Heck, even India & Pakistan got nukes. How about the Taleban? How about you? Get yours today!
--
So they plan to wipe out Telford on on Oct 16 2023, but "The impact would be accurate to within a few hundred miles...". So it's also very well possible that they miss England alltogether? Sounds like a good, well thought out, plan to me **chuckles**.
So an asteroid strike would make vast areas of land inaccessable for the masses? How is that like golf?
All in all, this is very much like golf - so it's a good comparison in my book! :)
Yeah, I can see the apology now: "Sorry we blasted Paris away, we thought we used metric values to calculate the trajectory..."
I'm sold on the concept so far. So do they want donations to help now or what?
All you need to do is nudge a small space rock.
This could be done with non-nuclear rockets...
An ion engine with a couple thousand pounds of fuel comes to mind. Storable, Efficent, Hard to Detect...
Remember they estimate size of the rock that caused the 1908 siberian explosion is 50 meters (1/2 a foot ball field).
Link here
Doesn't take much to change the orbit of a rock that small.
TastesLikeHerringFlavoredChicken
TastesLikeHerringFlavoredChicken
In the "One World/Black Helicopters" conspiracy mode....
What would happen if you dropped a rock on Jeruselam and then got the TV hair-do evangelists to chat up the "wrath of God" angle? What would the various sects argue about then?
According to the people they don't let out too often, a water hit is worse than a land hit as well.
There is a Scientific American article about the relative damage wrought by land and sea asteroid impacts.
While I think Science for Science's Sake is a very worthwhile endeavour as it always adds to our understanding of the universe, this story makes me sick.
I cant say anything more than "Why the fuck would anyone/country want/need/desire/imagine/devise/whatever a scenario to kill 10million people by dropping a fucking asteroid on them". The same logic that wants to put up ICBM missle defense grids are the same that want to spy on China are the same who want to extort apologies are the same that want to kill palestinians are the same that want to sign the FTAA are the same that want fund studies to divert asteroids into the planet - who the fuck are these people and who put them in charge?
Are they going to have a guy in a space suit and a cowboy hat, doing that scene from Dr. Strangelove as the asteroid goes down?
Gentlemen, we must not allow an asteroid gap. Otherwise we could lose our way of life and the essence of our precious bodily fluids.
The evolution of human warfare:
- Throw Rock
- Hit other guy with stick
- Hit other guy with sharp stick
- Shoot stick at other guy with curved stick
- Hit other guy with sharp copper stick
- Hit other guy with sharp bronze stick
- Hit other guy with sharp iron stick
- Hit other guy with sharp steel stick
- Shoot stick at other guy with REALLY BIG curved stick.
- Shoot stick at other guy with stick with trigger.
- Shoot metal rock at other guy with rock with trigger.
- Drop exploding metal rocks on other guy
- Drop unstable atomic metal rocks on other guy
- Throw rock
Wow! Isn't human progress impressive?
-PARANOIA is fun. D20 is not fun. The Computer says so.
-The Computer
Satellite exploded just when it hits the Earth atmosphere, we all die a long painful death. Then a giant asteroid hit the Earth. Million years later, giant intelligent ants (the new dominant specie on Earth) wondering if an asteroid wipe out the apemen. I am pretty sure that is what happened to the dinosaurs...
Are you thought the Russians are crazy!
====
Codeala - Just another mindless drone
NOT LA. I live in LA. Granted taking out 1. Hollywood, 2. Celebs, 3. The Church of Scientology tm, (C), etc. I'll move. Bastards.
Arathres
I love my iBook. I use it to run Linux!
stainless steel
Coventry is much more worthy of Annihilation!
:-(
Telford is on my doorstep, anyhow - so there won't be much left of me
New Slashdot poll:
Best place to plant an Asteroid:
1...Los Angeles
2...Seattle
3...Melbourne
4...Coventry
5...CowboyNeal
In their simulation, the expected error was a few hundred miles. In other words, aim at England, hit France or Ireland. Mostly this is because you can't adjust the power of the steering nuke blasts -- it's like putting with hand-grenades. Get a better propulsion system and you should be able to get pinpoint accuracy -- but it might take a few practice shots to figure out how much atmospheric entry will deflect an asteroid of a given size and shape. NASA's first manned flights came down up to a hundred miles off target, and those capsules were far more steerable than a rock.
Asteroids are next to useless as weapon.
Firstly it will take months to devise "fire solution" which is useless in terms of a hairtrigger engagement. The element of surprise is completely lost when your craft take of to rendevous with the asteroid, and all it would take to shut down your plan is a quick nuclear strike by the opposing side. Thirdly the path of your asteroid has to be so precise if you want it to hit an exact target at an exact time, and you won't get that kind of accuracy with nuclear blasts. All in all it makes a pretty poor weapon
let's work out the sums:
Impact speed : 11km/s (minimum) - escape velocity.
15 small nuclear bombs, let's say 20MT yield this gives 300MT.
1MTonne TNT=4.5x10^15 Joules IIRC.
Hence a yield of about 10^18 Joules.
Taking KE=0.5*m*v^2
This gives m = 2*KE/v^2
m= 2*10^18/(11000)^2 = 10^10kg (approx)
Using a density of about 10^4 kg/m^3, Volume is about 10^6m^3.
This means that we're talking about an asteroid of diameter 100 metres here. That's getting a bit big to be an unknown asteroid (subject, of course, to any stupidness on my part, and the usual rounding errors). This is not an infeasible size for the application though - we track a very small proportion of these objects.
However, a smaller asteroid (which are more likely not to be tracked) would still cause pretty major devastation.
The problem for any would be despots would, of course, be making an undetected launch to deflect the asteroid, rather than deflecting the thing. Also there's the problem of deflecting the object in a controlled way (the method given sounds a little hard to fine tune).
For a related weapon (this time rocks fired from the moon), read 'The Moon is a Harsh Mistress' by Heinlein. (Amazon.com/Amazon.co.uk)
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Murky
Murky
A wannabe geek with no money to geek with.