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NASA Plays Well With Comets
jmichaelg writes "Taking a page from Hollywood, NASA approved a Deep Impact mission to poke a seven story hole into Comet Tempel 1. It's a little tough to get past the grandstanding on NASA's part - the collision is scheduled for July 4, 2005. OTOH, hitting an asteroid something NASA has to demonstrate they can do. They missed on their first attempt at an asteroid rendezvous and spent a year chasing Eros. Clearly, they need a bit of practice. Last year, Los Alamos Labs detected two meteors impacting the earth. The bigger of the two explosions was estimated at between 6000-8000 tons of TNT which is 1/2 to 2/3'rds of the bomb's yield that was dropped on Hiroshima. The Tunguska comet/asteroid explosion in 1908 was the equivalent of a 15-40 megaton bomb. The Near Earth Asteroid Tracking observatory keeps turning up previously unknown near earth asteroids all the time so it's just a matter of time before NASA will have to deflect or destroy an incoming asteroid lest it destroy some part of us." We ran another story about this earlier this year.
50,000 miles per hour is 80,000 kilometers per hour, or about 22,000 meters per second. 0.5*(22,000)^2 = 242,000,000 Joules. That's 67 kilowatt hours, or 5.9 X 10^-8 megatons TNT per kilogram of haul-ass cosmic rock. Want a one megaton blast? A mere 17,000 metric tons of asteroid will do it. The density of rock is about 3 grams per cubic centimeter. So 17,000,000,000 grams of rock in a roughly spherical shape would be about 26 meters (or about 80 feet) in diameter. Lots of luck seeing that one coming, bucko!
When in the last...oh...thousand years have even 1,000 people died from a metorite strike on year?
Personally, I find your figure of 300,000 dying each cenury a little far fetched.
Unless you are counting all the dinosaurs that geeked it when the Big One hit back in 65,000,000 B.C.E.
Well, theres a lot of documentation out there about the Fire, and nothing points to metor strikes.
http://www.chicagohs.org/history/fire.html
"The summer of 1871 was very dry, leaving the ground parched and the wooden city vulnerable. On Sunday evening, October 8, 1871, just after nine o'clock, a fire broke out in the barn behind the home of Patrick and Catherine O'Leary at 13 DeKoven Street. How the fire started is still unknown today, but an O'Leary cow often gets the credit. "
NRO would provide image-processing and other sensor technology, and ops. They have some pretty sophisticated capabilities, both in Earth-sensing and data analysis, like their attempt to find the Polar Lander from MGS images.
NSA. Hmmm.... Comet smacking Earth, causing death and chaos... Couldn't possibly be a national security issue with huge implications for domestic and foreign upheaval, could it? 8/
gigantino.tv - Heavy but weighs nothing.
NASA doesn't really have the capability to do an asteroid deflection. There is only one organization, probably in the world, that could handle it: the US military.
Sure, NASA would be used for some consultation, but any deflections would be an AirForce/Boeing/Lockmart/NRO/NSA endeavour. The military is used to working under severe time and situational constraints, NASA is not. It might cost tens of billions of dollars, but the military will be able to accomplish it, whereas NASA would do something like forget to convert imperial to metric.
When the time comes (and it will), NASA will be a consultation and tech resource, nothing more. The rockets will be commercial Deltas or Titans, the nukes will come from the Air Force, and the failsafe methodologies will be purely DoD.
gigantino.tv - Heavy but weighs nothing.
The impact will go well. It's far easier to impact than to orbit and/or land. If the impact vehicle goes into "safe" mode at the wrong time, it'll just make a shallower pit. The more interesting question is how the observatory part of the mission is going to slow down to orbit the comet for observations ahead of the balls to the wall impact vehicle...
The willful destruction of cosmic property - the Aliens aren't going to like this. We should expect 'contact' shortly thereafter.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
300,000 people die each year from tobacco. I've heard numerous reports of people being added in that statistic for things like smoking while driving and getting in a car accident and other vaguely connected statistics.
As for your statistics, I think you are just way off based. Tunguska wasn't even really thought of as a meteor strike, and the closest town (Irkutsk) only showed a spike on a siesmograph.. I think the only large group of living organisms killed by that meteor was reindeer.
95% of statistics can be skewed to support an argument.
Dacels Jewelers can't be trusted.
But first, the paniced masses must be given hope by the Hero in a 2.5 minute monologue, followed by cheers all over the world... :-)
(I don't dislike american action movies, but they certainly are predictable - just as the american view of the world and the american position in it)
I just don't see the obvious in US alone saving the world...
Yeah! Let Canada do it! Or Uzbekistan! At this point, it's not terribly likely that anyone besides NASA would be in a position to do this... Maybe the US can trade an asteroid deflection for forgiveness of unpaid U.N. dues...
Boss of nothin. Big deal.
Son, go get daddy's hard plastic eyes.
Expanding a vast wasteland since 1996.
The Air Force has been tracking this stuff for decades, tons of stuff hits the earth every mont, and a large, tunguska sized chunck hits on the average of every 10 years. We've been lucky so far, the tunguska asteroid came in at a very shallow angle, which caused the explosion to be amplified (and butterfly shaped if you care), and most of these rocks hitting us hit in the middle of an ocean, or near the poles, or some unihabited region. But they do hit, and the air force just released gobs of documents just recently about stuff they've been watching since the late 40's.
Statistically speaking, they say that 3000 people die in a year from meteror impacts. That's not to say that 3000 people die every year from this, its an average, 300,000 people die every century.
--Nuintari
slashdot : where an opinion can be wrong.
two words man, orbital mechanics. People need to realize that flying around in space is NOTHING like flying around in the atmosphere. Everything is in circles. You have gravity influence from the earth, which you are cirling, all and all the major local masses, especially jupiter and the sun.
For instance, you wanna get to a probe that it is the same orbit, and therfore, going the same speed as you. You speed up, which transfers you to a higher orbit, and you have to pass the thing by, and drop down to speed and it comes up behind you. IF you time it right. It takes supercomputers to calculate this stuff, the math behind it is so complex that it exceeds Einstein's physics.
People need to stop belieing that space travel is like we see it on Hollywood, cause its not.
--Nuintari
slashdot : where an opinion can be wrong.
Its all an estimation dude, because recorded history gets chopped before printing was invented, and even after that, most of it was religious for a long time. And again, I must reiterate, its an average based on data from a VERY LONG TIME. We haven't had any substancial impacts in this cetury, and we had one last century (in tersm of death toll, tunguska killed a few hundred people or so). But what about 500 AD? 0 AD? 500 BC? That's a long time and there are a lot of fluctuations in populations very small areas, and evidence of impacts occuring at th same time.
Stop thinking about it as a "3000 must die every year" its an average based on data pieced togther since man started walking.
--Nuintari
slashdot : where an opinion can be wrong.
in the fifties, this was all done by hand. Imagine doing stuff they teach in graduate level classes at universities with nothing but a slide rule and a pencil and paper. people can't even do that anymore.... well, nasa does claim to have a guy who can do orbital mechanics in his head, personally, I'd like to meet him. He's probably deranged.
--Nuintari
slashdot : where an opinion can be wrong.
I've seen a professionally offended societal go-gooder upset enough by something they imagined could be seen in an image of a solar flare's glowing burst of gas that they forbade it as a cow-worker's MS Windows wallpaper.
From past interactions with the religious types that might be paranoid about the same thing, I think it's a tossup whether they would blame NASA or that horrible Devil Comet.
Presumably the plume from the impact would dissipate fairly quickly, but for a while recognisable shapes might be crafted.
And then there are the commercial possibilities, the advertising value of having your company's logo displayed across the sky for all in viewing latitudes to see should be worth a big donation to NASA. Or maybe the initials of someone who has too much money to throw away, like amateur astronaut Dennis Tito, could be tapped to subsidize the mission.
The possibilities are as endless as the bounds of bad taste!
It's hard to tell for sure how much copper is involved. The site linked to, and the press release linked to from there, give 3 possible masses. Well, actually, one mass and two quantities of force - it will weigh a variable amount in pounds under acceleration and zero pounds once in free fall, but will maintain the same mass in kilograms throughout.
Okay, since copper is not a precious metal I'll assume we aren't talking troy pounds. So is the impactor:
770 pounds (349.272 kg)?
771 pounds (349.7256 kg)?
350 kilograms (~771.605 Pounds)?
Naturally, the USA news services that picked up the press release judt dropped the "350 kilogram" number. Hopefully NASA will figure out exactly what it masses before launch. Navigation would go so much better!
After accidently plinking Mars with that probe, hasn't NASA learned to work in the metric system yet?
And is that Avoirdupois or Troy pounds?
ahem
NEATO -- Near Earth Asteroid Tracking Observatory
In mathematics, one does not understand things, one merely gets used to them.
--VonNeumann
Funny, I spent a large chunk of my earlier years attempting a women rendezvous and spent years chasing Eros (love/lust).
"Can of worms? The can is open... the worms are everywhere."
OK, clueless dude. "megaton" = equivalent yield to one million tons of TNT.
Therefore, Tunguska was anywhere from 2000 to 6700 times more powerful than the referenced explosion.
Sheesh! Can't anyone do simple math anymore.
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
For those of you having problems loading the animations from the NASA site like I was, here's a mirror:
http://deepimpact.umd.edu
an astroid strike on earth might really not be all that bad -- as long as it hits the right part of the world.... say, New York, Distict of Columbia, or California.
Of course, it would really suck if it missed DC by just enough to hit one of the nuclear power plants in VA....
Don't you think it's time to start communicating?
Does this mean that when we ram into it we will have a recording that says: BOOOOOOOOM SHAKALAKA!
Hmm...or was it The Learning Channel. I was just watching TV and they had the store camera video show (the one with the thief who puts down his rifle, but not the tank one). Oh well...aren't TLC and Discovery owned by the same company? Have to do some research tonight and make sure I have my facts straight.
"These people look deep within my soul and assign me a number based on the order in which I joined" --Homer re:
Sure, but they could at least get NEW ones once in awhile....that's my main beef with them, and not show the same ones five times a day!
"These people look deep within my soul and assign me a number based on the order in which I joined" --Homer re:
...The Discovery Channel.
If it's not police chases, it's Egypt.
If it's not Egypt, it's asteroids and comets
If it's not asteroids and comets, it's a feature on something that's being shown in the latest movie (Pearl Harbor, Egypt, etc)
That thing with the Russian comet air burst was on for *hours* last night...it was inescapable (except for a thing on minesweepers [yep, the game, obviously] on History Channel).
The Discovery Channel has become the "EgyptPoliceChasesAsteroidsTopicalMovieStuff" Channel, but must Slashdot follow suit?
And if I'm flipping through channels and I see that security camera recording of that convenience store robber who puts his rifle on the counter, and the clerk grabs it again, I'm going to have an anuerysm. That, or the police chase with that guy driving a tank down the LA freeway.
"These people look deep within my soul and assign me a number based on the order in which I joined" --Homer re:
Here is the BBC's article on it...1 351000/1351431.stm
http://news.bbc.co.uk/hi/english/sci/tech/newsid_
This is about research, not about blowing up comets to save the earth.
Got Rhinos?
Unless, of course, the software decides to trust the wrong gyroscope, sending your spacecraft into a spin and taking it months to precess back to the point where it can get enough power to thaw its fuel. :-)
BTW. Awsome work you guys are doing. And glad you guys were able to get it back after the accident. How's the SUMER instrument doing?
"You saved 1968." - Ms. Valerie Pringle to the crew of Apollo 8
I work with scientific spacecraft, and I'm still always surprised at the precision with which we can determine distances and positions of distant objects. SOHO is a million miles from Earth, and its radial position is known to within a few centimeters.
Barring egregious mismanagement, it's not that hard to hit celestial bodies -- we have the right tools for the job!
The chances of the earth being hit by a dangerously significant item from space are far lower than the chances I get hit by a car before I make it home tonight. People there is no news here, go home and relax and worry about something real like rising taxes and falling stocks.
"You can now flame me, I am full of love,"
No recorded deaths due to people being hit in the head or whatever, but a family died in Eastern Europe last year when a suspected meteorite crash set fire to their house. Basically, the biggest reason for there being no recorded meteorite deaths is that its blimmin' difficult to prove them as such - eyewitnesses say they saw something fall from the sky onto the thatch roof causing it to set alight, but without definite proof its another unconfirmed.
"I Know You Are But What Am I?"
Los Alamos didn't actually detect the meteors impacting the earth. They detected an air pressure wave given off by their entry into the atmosphere. They don't know whether they hit the earth or not. There was no actual explosion with energy equal to 6000-8000 tons of TNT. Instead the magnitude of the pressure wave was the same as it would have been if caused by such an explosion.
Physics, Cosmology and
I stand corrected, I meant to say metallic. And iron of course would be considerably more likely. Its one of those things the spell checker don't catch, and at this hour of the night neither does my brain :-)
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If you can't blind them with brilliance, baffle them with bull.
Well I suppose it is a matter of time, but we could be talking throusands or even millions of years here.
Only nickel core objects can make it to the ground (everything else explodes in the upper athmosphere). These are rare enough. So a very large object would be needed before a big Megaton force blast is felt on the ground. And based on the size of the objects and how often these hit, the mean time between earth impact is large. On the order of thousands of years.
Personally, I don't think its something that is likely to happen in my life time. That said all these sky surveys for Near Earth Objects is to correctly assess the risk. The current margin of error in the calculations is large.
Then again I could get squashed by a giant falling rock before I fini
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If you can't blind them with brilliance, baffle them with bull.
Ah, but if I'm not mistaken, NEAR was operated by JPL, not NASA; perhaps that's what you meant?
Actually NEAR was operated at Johns Hopkins and funded by NASA. NEAT is operated by JPL and also funded by NASA.
Nasa can only be deemed capable of "planetary defense" if they get plenty of practice doing this kind of thing. Consider the Mars probes that failed for a variety of reasons and the jammed antenna on the Jupiter probe for examples of what can go wrong. The more practice NASA gets, the better off we'll all be.
From the report you cite....
The make up burn placed NEAR on a trajectory to rendezvous with Eros on Feb 14 2000, 13 months later than originally planned.
Granted, they recovered from the initial miss, but the fact is they did miss on the first try. It doesn't matter if it's "an engine burn anomaly," the result is a miss on the first try.
I'm not castigating NEAR or NASA for missing on the first try. My point was that if you're trying to deflect an asteroid, you had better be where you need to be on the first try - you may not have time enough for a correction. The way to increase the odds that a "hose up" won't happen is to give NASA/JHU APL/JPL/... lots of practice.
Hmm. I amend my statement to say "with the original sensors launched on board in 1993" since I do recall reading such a thing at that time. However, since the telescope can and has been updated in orbit with new instruments, it looks like they've overcome this. Notice that the moon photos were taken with "WFPC-2" ... there was a different WFPC earlier on.
i am a soviet space shuttle
Deep Space One is an experimental probe designed to test ion propulsion and semi-autonomous operation. Deep Space Two was an auxiliary payload on the Mars Polar Lander that was designed to send two impact probes to drive into the surface of Mars and perform tests (they were lost along with the lander for unknown reasons.)
What will happen when we get to Deep Space Nine? According to the back of one of my DS9 novels, the phrase is trademarked. Will Paramount raise a fuss when NASA gets far enough along in the project series to argue with them? I hope not, since it'd be great PR. Besides, I don't think you can really trademark the term when used that way. They also tried to trademark "USS Enterprise" some time back, but the Navy understandably got upset and gave them some smackdown. I'm sure the thousands of sailors who have served on her agree with the sentiment.
Still, I look forward to seeing what Deep Impact can do. It'll help us carry out a mission like the Messiah's in the future if it ever becomes necessary in reality. (The Messiah, by the way, is an incredibly cool design. Who would have thought you could combine the Space Shuttle, ISS modules, Energia/Shuttle booster rockets, spare external tanks, and a NERVA engine so exquisitely?)
i am a soviet space shuttle
To this day, the military has not specified what that payload was, though I speculate that it was likely a KH-12 spy satellite or a similar vehicle, which is reportedly very similar to the overall design of the Hubble telescope but optimised for looking back at the Earth instead of toward the stars. Using different sensors, of course; Hubble would be blinded if it pointed at the Moon or Earth. Hubble, incidentally, is one of the few payloads to even come close to filling the entire payload bay. Hubble filled nearly all of it; the emptiest shuttle mission ever was the first flight, STS-1 -- carried out in April of 1981 -- that carried no payload whatsoever.
Hoodwinked? No. They actually had input on the design and helped to make its development into a working vehicle possible. DoD stopped putting military payloads on the Shuttle because one has been lost. It seems that the military believes that one loss in 25 missions is unacceptable, even though to this day there have been none since in over 75 more missions. This is actually a good record, since there have been mishaps with just about every launch vehicle out there. It's just that the loss of the Space Shuttle results in huge publicity (rightfully so) while the loss of, say, a Delta II results in a collective national yawn and a flip of the channel to a football game. Even the Air Force's workhorse the Titan IV has failed several times, not just once.The Shuttle fleet is too busy right now to accept a military mission in any case, however, since three of the four shuttles are constantly flying to the space station and the fourth, Columbia, has not reentered service after its last Orbiter Maintenance Down Period (OMDP). Columbia is too heavy to reach the ISS, so she will be flying science missions as the shuttle did for years before the ISS began assembly in 1998.
i am a soviet space shuttle
The Near Earth Asteroid Tracking observatory
Am I the only one that sees the abbreviation for the Near Earth Asteroid Tracking Observatory is NEATO?
I bet they did that on purpose, those crazy astronomers!
Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
last i heard they landed a probe not even designed to land, right on eros.
to me that's more than half the difficulty of a 'deep impact' mission, delivering your payload to the asteroid.
i'd say NASA is quite capable of planetary defense.
// "Can't clowns and pirates just -try- to get along?"
You're thinking of the KH-11 series of satelites. The KH-12 was, I believe, a radarsat.
Shave the Whales!
How easy to compare and contrast!
Uh, did anybody *else* find this a source of confusion? Don't you think that 'megaton' is a familiar enough term in general use that it doesn't need to be translated or converted? Sheesh.
-- We all have enough strength to endure the misfortunes of other people. La Rochefoucauld
Be sure to watch for this one. According to another article i read on this in this months issue of Popular Science (page 64) It will create a pit 25 meters wide by 100 meters deep which will launch a slow-motion plume of gas and ice into space.
The theory also says that the plume may spew into space months after impcat providing tons of data on the compisition of comets (which belive it or not we know very little about other than theroy).
"Don't mess with him, he taunts the happy fun ball."
OTOH, hitting an asteroid something NASA has to demonstrate they can do. They missed on their first attempt at an asteroid rendezvous and spent a year chasing Eros.
First, Johns Hopkins University Applied Physics Lab did all the mission design.
Second, JHUAPL didn't "miss" Eros - see the report. ...the main engine's normal start-up transient exceeded a lateral acceleration safety threshold that was set too low. It was an onboard software problem. Also, please note that NEAR carried out much more than its planned mission even after the hose-up. You really can't accuse anyone of having trouble "hitting an asteroid".
If I find out that NASA shoots down a comet that is headed for my back yard, I'll be pissed. Further, I'll sue for 'wrongfull loss of comet'. The bastards are stealing good space minerals that you could sell to tourists. What is capitalism worth when you have a comie space agency taking good space cash out of your pocket?
What is all this talk about knocking the comet away from a collision with earth? The article actually says absolutely nothing about an earth impact. The only collision is between the impactor sent by the fly-by spacecraft and the comet. The idea is, you blow a hole in the comet, and then that allows you to see what is inside the comet. That is it. They aren't knocking it away from an earth collision. This is a research mission. Calling it deep impact might just be a joke or something (because they plan on making a deep impact) but it seems to have nothing to do with the movie.
and why does NASA have to do it? Maybe our time here is up and we should be obliterated. And this may be the only way to destroy the evil empire that is Microsoft. I say let the commet come and hope it hits Redmond!
Now, wait, there has been quite a number of probes which missed their targets; can you name any, other than NEAR, which caught up with their target after doing so at the first encounter? Perhaps Japan's Planet-B in 2003, kind of... And which performed a soft landing on said target? None so far.
Ah, but if I'm not mistaken, NEAR was operated by JPL, not NASA; perhaps that's what you meant?
NASA no longer is adapted to crash-course missions; they'll ask for 10 years and/or a few trillion dollars. Better contract with private companies...
Megaton = 1,000,000 tons. 8,000 tons of TNT = .008Megaton
The only casualty on record is some woman in Kansas or Oklahoma, who was bruised when a small meteorite crashed through her roof and hit her on the hip while she was napping on her couch. I think this was back in the 1950s.
I said "recorded," with the understanding that there's a lot we don't know. I've never heard of anyone being killed by Tunguska. I hadn't heard about the Eastern European incident last year, but I stand corrected on that one.
Sorry, just can't stand to see a good quote gone wrong.
Steven N. Severinghaus
Any chance you have a URL with some more info on this? (You can imagine what a Google search on 'band of material' brings up :). Unless you're talking comet debris, and most of that is pretty tiny, I'd be curious as to just where this material is coming from, and how anyone detected it.
Reminds me of a really neat book from 1987, Exit Earth. The solar system is passing through some kind of matter that makes the sun go semi-nova, and to save humanity these big space-arks.. well, read it youself, it touches on some points that you normally don't see in sci-fi disaster novels.
Endless arguments over trivial contradictions in books written by ignorant savages to explain thunder in the dark.
How about the fact that any reasonably sized asteroid is large enought to cause severe climactic and atmospheric damage. The equivilant of nuclear winter. A water hit is in some ways even worse than a dry land hit. If it does hit dry land you won't be building anything there for a long time. It would take quite a while for the crater to cool down and there would probably be seismic disturbances for decades. I'm willing to bet that any dangerous sizes body hitting the Earth would cause enough of a rumble in the crust to cause fault lines all over the world to release any built up pressure.
"If there is nothing you are willing to die for, then you are not really alive." Myself
At the moment there isn't another nation on the face of the planet with the resources and capability to pull off such a stunt. Please call again when yours can. Thank you have a nice day.
"If there is nothing you are willing to die for, then you are not really alive." Myself
They have the knowledge and capability to do it given enough time But I doubt if they have parts on hand and in working order that they could adapt to the problem in a reasonable amount of time. The ESA doesn't have anywhere near the launch experience we have and would have to get the approval from the member states which would be time consuming. Russia has the launch experience but probably couldn't cobble together a solution in enough time. There have been entirely too many PHA's that were right up on the Earth when discovered. The US is the only space capable entity on Earth with even a remote chance of cobbling together a solution quickly. Especially if that required solution would require multiple space launches to achieve. A creative and quick thinking genius could pobably work out a solution using only off the shelf parts.
"If there is nothing you are willing to die for, then you are not really alive." Myself
Right now, NASA is getting its budgets squeezed while the current administration promises large amounts of funding for son-of-SDI type programs. If NASA wants funding, perhaps it would be better off making peaceful, scientific, programs look like hard-core military projects?
--
KMSMA (WWBD?)
they named their project after the wrong movie
That does make some sense though. I think we all would agree that NASA has had some bad luck lately, and there isn't alot of popular support for the space program in the US right now, AFAIK. "Blowing stuff up" is more interesting to the average American when compared with research. Broadcasting the collision could make for a good media event, if done better than the J. Glen launch or the Mars landing. Potentially more... spectacular. I know I'll be watching.
Even if it looks like a duck, and quacks like a duck, you can't be sure until you see the RealDuck
If so, imagine we perfect cold fusion power, so we have an infinite source of electricity. Then we just charge up the asteroid with a like charge to some large body we can maneuver, and viola! It's deflected.
Or we could surround an area far above the earth with a metal net, and put opposite charge on the net and the asteroid so it will be caught. With infinite electrical power, I bet this would be possible.
Then again, maybe doing a magical fairy dance in your underware at sundown would do the same thing. Do I need a physics lesson?
Send 2 incredibly charged plates into space - no danger of discharge because space is a vacuum. When they near the asteroid, some gas is released that floods the region between the plates and surrounding the asteroid. Of course the gas ionizes, and one huge spark jumps between the plates, vaporizing the asteroid. The great thing about this method is it can't be used as a weapon, solving one of the concerns about nudging asteroid into earth's orbit.
Hubble would be blinded if it pointed at the Moon or Earth
Not True. Look here.
As far as I know, Mercury and the Earth are the only planets Hubble has never looked at.
Which fact ? The global warming hypesters have a lot of little psuedo maybe-facts wrapped up in their stuff. Has the earth gotten warmer in the past 20 years ? Yes. Was it due to CO2 ? That hypothesis requires a huge amount of tweaking specialized computer models to make it match up with the data -- predicting Florida election returns with trained neural nets is more respectable, in my opinion. Remember, less than 20 years ago these same "scientists" were trying to get us all riled up about a coming ice age. Will the sea level rise or fall if the average temperature increases ? They can tweak their models either way. Some of them even say that there will be more snowfall in glacial areas, and invent a process which puts us all in an ice age. The one constant in all the models is that we are just flick of a butterfly's wing away from a cascade of causes and effects that ends in total disaster. Because otherwise, the study would not be published.
If the US found a cheap, safe, pollution and CO2 free way to make as much energy as we wanted tomorrow, the Sierra Club and the European Greens would fight it tooth and nail. Why ? Because they don't care about these "facts" of global warming and oil shortages and whatever; what they have is a religion, a faith that says the United States and other industrial nations committed some sin by being rich, and we must pay for it, preferably by giving away a lot of stuff to third world countries, and by sacrificing and suffering and walking around in hemp sandles instead of riding SUV's until our minds are appropriately aligned with the sanctioned TRUTH. Greens and Sierre Clubers would find a technical escape from their invented apocalpse extremely upsetting. That's the main reason why I'm for nuclear and wind energy, not because I actually want to save the world or anything stupid like that -- it's just a great troll of those stupid Kaczynskites.
. . . announcing to slashdotters the depth of your ignorance. . .
That never stopped me before . . .
. . . the fact that you have done NO research in any of these subjects . . .
Well, all of my nasty sniping and hyperbole aside, you would probably be surprised to know what I've done and read. Of course, I took it beyound your level of browsing a couple of articles in Scientific American and Discover, and then masturbating to the thought of how enlightened and politicaly correct I was. Get of the net moron, I think there is a cup of wheat grass or carrot juice or $6 coffee calling your name somewhere.
TLC and Discovery have had a lot of impact-scenario shows on lately. What's the sudden fascination about? Simple: The fact that many times in the course of natural history, entire continental, and indeed, global populations have been wiped out by these impacts - and for the first time, Earth has produced a specied that can not only survive it, but entirely prevent it (maybe).
There is an extremely low chance of such a massive collision in the next few hundred years, at least - what should be worrying, instead, is a smaller impact in the Pacific, which could wipe east-coast Japan off the map. These impacts happen much more frequently, some claim once every 10,000 years, and one might be coming soon due to the band of material the Earth is soon to encounter. The effects of such an impact on the global economy are incalculable, and the probabilities of such an occurance are much higher. The Japanese government is growing increasingly concerned, and are considering a 2 to 4 million dollar annual budget for the identification, tracking, and destruction of likely impact masses.
In fact, if the Russian impact of 1908 were in fact a metallic body (as is almost entirely disproven, at this point), and had struck the Pacific instead, this destruction of Japan would have already occured. And when you think about it, a few thousand miles of earth's surface is not a very wide safety margin, relative to the massive distances traveled by these objects.
One comment made in a recent TLC program on this issue strikes me... "Think about it: The number of people we have who are specifically employed to track these objects is smaller than the staff of a neighborhood McDonald's"
think for yourself, you won't like the results if others do it for you.
If Hiroshima was 6-8 Megatons and Tunguska was 15-40 Megatons (a really wide range, mind you) then we should truly fear the "aging" soviet arsenal of "city-busters" reputedly in the 100 Megaton range. For comparison, charts I've seen of England show zones of absolute destruction from a 10 Megaton burst in the narrow "neck" of the island wiping out most of the island. 100 Megatons... well, it's a wash exactly how bad the damage is. Some scientists fear that city-busters are so huge they might actually affect the tectonic plates of the earth's crust. That's why I loved the U.S. military approach claiming that the U.S. maintained a "strategic" advantage because the Soviet missiles were "less accurate" than ours. Ha! One thing which a city buster does not require is micrometric precision in targeting. Modern MIRVS (Multiple Independently-targeted re-entry vehicles) reduce the yield of the individual warheads down to about 600-800 kilotons each, but such missiles are limited to 10 warheads per ICBM under the SALT treaty (there's a 12-warhead capacity on the U.S. Minuteman missile - but we don't install those last two. Really. We are prepared to launch off-balance missiles...) SO really, if you want to compare modern missiles with the crude devices lofted at the end of the Second World War, you would see that modern ICBMs can hurl about a dozen warheads, each large enough to utterly destroy a few square miles without leaving a single crater deep enough that it becomes a lake. Isn't progress wonderful?
"Me go fast in rocket. Boom-boom blow up comet. Wheeeeeeeeeeeeeeeee!!!
--Ben Affleck "Armageddon"
At least when intercepting an asteroid or come, you can get an idea of the thing's orbit from Earth (although with a comet you have to allow for random outgassing). However, to destroy or move an asteroid or comet, you have to know mass and composition. This is the sort of thing that would have to be determined by a probe, with a high degree of detail. Knowing the composition of a tiny piece won't do - you have to know what most of the asteroid is made of with a high degree of certainty, and where all the different material deposits are located in order to find center of mass.
Right now, we don't have the ability to do that. This interception is, in reality, rather meaningless from an Earth-protection point of view, although it is cool. And of course, there's always the scientific benefit.
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