scientists do not understand

tony873004 · Jul 12, 2007

Why would it be travelling 30 miles per second? That's its solar orbital velocity. It is travelling 30 miles per second relative to the Sun. The spacecraft carrying the nukes would match trajectories and speeds with the asteroid, just like would be required for the Gravity Tractor idea. The Gravity Tractor won't work very well if it whizzes by at 30 miles per second. It needs to hover virtually motionless above the asteroid. I'd prefer to land the nuke on the gently on the surface before detonating it. Perhaps nuke it twice, once to melt the surface and form a rock vapor cloud so the second nuke would have a medium for its blast wave to travel through. I made a simulation of the trajectories of the fragments of an asteroid blown apart. Screen shots are included in the explanation. I started with Apophis, the asteroid that will make a close passage to Earth on April 13, 2029, and if it passes through a keyhole, will return to strike Earth in 2036. Apophis' orbit prior to being perturbed by Earth on April 13, 2029: http://orbitsimulator.com/gravity/images/n02.GIF Three years prior to Apophis' 2029 approach, I created another asteroid I call "Impactor". This object is placed 800,000 kilometers from Apophis, following a virtually identical orbit, except it will impact Earth on April 13, 2029: http://orbitsimulator.com/gravity/images/n03.GIF I then created 200 objects that radiated away from "Impactor" in random directions, half of them at 10 meter per second, and half at 1 meter per second: http://orbitsimulator.com/gravity/images/n01.GIF I choose 10 meters per second for the first group of fragments because if the Castle Bravo nuclear test could excav

oscar1 · Jul 12, 2007

Ah yes, but you are expecting that we might have to deal with a rock that subscribes to the Geneva Convention. I was thinking along the lines of two or more asteroids in the belt interfering with eachother such, that one of them alters course and comes virtually straight for our window. We would then have a mere couple of years at the very best, depending on when we spot the thing coming. I reckon that a guardian asteroid circling the Earth would be a kind of goal keeper on the bench, that can enter the game on rather short notice.

tony873004 · Jul 12, 2007

That's a fun idea. And we'd have a 2nd moon! But realistically, to capture an asteroid into Earth orbit would require that we slow it by several kilometers per second during the brief several hour window that it cruises through Earth's Hill Sphere. If we could do that, we could just deflect threatening asteroids directly using the same method. It's very unlikely that two asteroids in the belt could interfere with each other significantly enough to send one of them on an Earth-crossing orbit. And even if they could, such an asteroid would likely make thousands of orbits before finally meeting up with Earth, giving us a generous amount of prep time. Two asteroids that collide in the belt would do so at low velocity, since they orbit in the same direction. An asteroid travelling 30 km/s around the Sun crashing into one travelling 29 km/s around the Sun hits at only 1 km/s. They would fragment and the fragments would spread out in orbits nearly identical to their original orbits. This is theorized to be the cause of many asteroid families such as the Vesta group, whose asteroids share similar orbits with Vesta, and have similar spectra. It is believed that they were once part of Vesta and were created when Vesta suffered a collision. But there are pleanty of scenerios where we could be surprised by something that gives us only a few years warning to no warning at all: Aten asteroids. These asteroids spend most of their time closer to the Sun than Earth, so they are hard to detect. They often approach from the direction of the Sun, and are discovered after their close approach. All other asteroid groups: We tend to discover them when they're very close to Earth, and there are still a lot awaiting discovery. Long-period comets: I'm least worried about these. Their high velocities make them dangerous since their kinetic energy is increased by their velocity squared. But unlike Earth-crossing asteroids, who

qso1 · Jul 13, 2007

1: Currently, if an asteroid is detected heading our way. There is nothing we can do to stop it. This is why some type of system has been proposed from time to time. Problem is, the threat is simply not taken seriously enough to start building a system. A system could very simply be composed of a few ICBMs with nuclear payloads that would be used to deflect an asteroid while its still a considerable distance from earth. Like cancer, early detection would be the key. I know of no funded, dedicated project that anyone is working on at this time. 2: Nobody yet knows what causes gravity and for those with claims they have or are working on antigravity. They are shunned in part because they provide little in the way of proof. They usually do not even have any peer review of their work. One day this may change and if it does, it will in part because the research will be verifiable. I know of no plasma weapons that are operational. During the Reagan years, such weapons were studied but much of what was known as "Star wars" in his Presidency, never became operational due mainly to expense and ease of countermeasure development. 3: Science in public school these days is pretty poorly taught from what I have heard. The moon landing is briefly touched upon if touched upon at all. To say nothing of how gravity is taught. At least in the case of gravity, scientists themselves still know very little about how gravity works or what its source is. It does seem to have something to do with large collections of mass. And theoretically, even a mass as small as a dust kitty could possess gravity. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

fingle · Jul 13, 2007

I'm not sure but isn't one of the reasons that nuclear bombs are so destructive, is because our atmosphere causes overpressure which directs or confines the concussive force of the blast down and to the sides ? So any design that is intended to shatter and scatter an asteroid would have to mimic that overpressure to achieve the same effects. Otherwise a lot of the destructive power would be wasted. I guess the bomb package could be made to dig or smash in by several feet sort of like bunker buster bombs. It would be really great if it could be tested, what ever happened to the nuke that some scare monger claimed the deep impact mission had ? <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

qso1 · Jul 13, 2007

Ooops, forgot to mention. The intent of the kind of asteroid mission I would design if I were designing for more than just stories...would be a mission of deflection. Not destruction. Change an asteroids course by a degree or two millions of miles out...and it misses earth. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

fingle · Jul 13, 2007

Even with deflection as the goal, the bomba will need to impart a large amount of force. So some method of getting the most bang for the buck is desirable. Yes ? No ? <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

oscar1 · Jul 13, 2007

"..to capture an asteroid into Earth orbit would require that we slow it by several kilometers per second.." Something like that, yes. I wasn't suggesting that we could do that in a relatively short period of time; it would in fact take decades. In my scenario we do of course need any rogue rock out there to postpone its diabolical plans until after we have our guardian asteroid in place. If that rock doesn't adhere to our 'needs', well, then we are buggered! "It's very unlikely that two asteroids in the belt could interfere with each other significantly enough to send one of them on an Earth-crossing orbit." What is the term "unlikely" worth in this context? We know that we did get hit in the past, but we don't know by what kind of rock. It could have been a comet, an asteroid, or part thereof, or even a chunk of material from beyond our solar system. Whatever it was, it would be unreasonable to assume we will not be hit again by 'something' some time in the future. So I reckon that if we are going to some day spend a trillion or so, we may as well spend it such that we exclude 'unlikely' alltogether; two for the price of one so to speak!

nec208 · Jul 13, 2007

The sheer velocity of the incoming rock would reduce a nuclear blast to no more than a pinprick. How so But I am referring to a major collision (no nukes involved), whereby a required portion of the mass of the projectile is [hopefully] instantly converted into 'path altering energy'. You mean not nukes but some big force that hit the rock.A collision that its the collision ? Ever see a fast car that is speeding and other fast car hits that other fast car? The biggect problem of course, is where can you get, and how do you harness the energy required. You need energy to move any mass. that mass is the cause of gravitation of matter is only an assumption albeit as sure an assumption as that one that the sun will rise and go down in the evening for example . Th bigger the planet the more gravity and your point is? reason is that no 'mechanism' of gravitational force is not known, we don't know how the mass is bending space and so it is I think just an assumption although it is as strong link (btw mass and gravitation) as it gets and you can take is for a fact unless you work on the theory of gravitation trying to show what the real mechanism is, in that case you consider the subject as open and call that an assumption From what others say here know one today know what causes gravity or much about gravity other the effects of gravity . <div class="Discussion_UserSignature"> </div>

kelvinzero · Jul 13, 2007

Hey, I think I might have thought of a way to compare nuclear weapons and asteroids without using all that pesky science. Nuclear weapons are described in terms of megatons of TNT. TNT would be not more effective than the same tonnage of hydrogen/oxygen rocket. A one km cube of asteroid would mass a billion tons (if it happened to have density of water), ie a thousand time more than our 'million ton rocket', assuming a one megaton warhead. I would guess from this that a megaton rocket could give some sort of nudge to a 1km asteroid if far enough out, but not come remotely near stopping or vaporising it.

wize1 · Jul 13, 2007

Sounds like a pretty good explanation to me MeteorWayne. We should however try working a little harder at comming up with a plan for asteroid protection. I agree, considering we don't have to prove that it does take place, it is a event that keeps happening, whats to talk about, lets get moving people.

nexium · Jul 14, 2007

As several have posted, we don't have a good plan for exact charting asteroids 20 years in the future, nor do we have good plan for diverting an asteroid nor a good plan for disintigrating an asteroid or comet. If we throw lots of money at all three problems, better plans are likely. One of the reasons for heavy lift, is it allows us to get a 50 megaton H bomb into solar orbit. If we have many big H bombs in solar orbit, we have a shot at letting the asteroid hit the H bomb head on. Because the speed difference is as much as 30 kilometers per second, we have to detonate the bomb about one microsecond after impact, otherwise the H bomb mechanism will be too hot = vaporized to explode. So the H bomb explodes 30 microkilometers, below the surface of the asteroid. Unfortunately, that is 30 millimeters below the surface. Deeper would be better. Is it possible to design an H bomb which depends on quickly vaporizing the front of the bomb to detonate? This might double the penetration, and also cause the bomb not to explode if it entered Earth's atmosphere, where it would take more than one second to vaporize the front of the H bomb. My guess is 50% of the 50 megaton asteroids will be pulverized, by a 50 megaton H bomb exploding a few inches below the surface. The other 50 percent, will still have a chunk 25 megatons or more, which may hit Earth. More massive asteroids and comets, will only loose a small percentage of their mass, and will be diverted by less than one second of arc. One second of arc is just as likely to convert a near miss to a hit as it is to cause a miss, so we likely should not nuke asteroids with more megatons than the rating of the H bomb we hope to collide. A typical 50 million ton asteroid is approximately a cube 250 meters (less than 2/10 ths of a mile) on each edge. Can we put 500 megaton H bombs in solar orbit? Neil

tony873004 · Jul 14, 2007

"Something like that, yes. I wasn't suggesting that we could do that in a relatively short period of time; it would in fact take decades." Even if it were in orbit around Earth, it would also take decades to position it to hit an incoming target. With decades of warning, the same effort could be applied to the incoming target itself. It is also likely that if we were able to position it to intercept the incoming asteroid, much of the fragments from the collision would still strike Earth, as the impact would only occur a few hours before the impending Earth strike. Even in my above simulation, I had to go back 3 years to get the 98% of the fragments to miss Earth. It is likely in your scenerio that at least half the mass of the incoming intruder would still stike Earth because of the short period of time between the asteroid/asteroid impact and the impending Earth impact. "whereby a required portion of the mass of the projectile is [hopefully] instantly converted into 'path altering energy'. " This is an easy pyhsics problem. You just use conservation of momentum. P1 + P2 before = P1 + P2 after. P1=mass of asteroid * velocity. P2=mass of impacting object * velocity. Consider the asteroid to be stationary, placing all the velocity in the impacting object. Let's use Apophis as an example. It is roughly 20,000,000,000 kg. Let's make our impacting object 100,000 kg. This is quite massive compared to other things we've launched onto interplanetary trajectories, but it would be reasonable to assume that our budget is virtually unlimited. Let's give it a striking velocity of 10 km/s. Again, this is a very high number compared to the velocities we've acheived to date. Before: 20,000,000,000 * 0 + 100,000 * 10000 = 1000000000 After: v=P/M 1000000000 / 20,000,100,000 = 5cm/s Not too bad, but it would require a strike decades in advance, as the simulation I posted earlier shows that even

oscar1 · Jul 14, 2007

We can calculate as much as we like, but we are dealing here, or might have to deal rather, with an unknown (beforehand) projectile coming for us. Considering that we are doing nothing at the moment in this regard, and that whatever strategy we design will cost a heck of a lot of money (where we have no system in place where the cost can be devided along the lines of it being 'fairly devided'), we are beggars rather than choosers. So we want to concentrate on avoiding destruction of the kind that wiped out the dinosaurs, or worse. Smaller pieces hitting us would certainly cause havoc and dispair, but so do the wars that we continually engage in, i.e. those are not the ones (even if they are fragments of a large rock that we disturbed successfully) we can afford to defend ourselves against. I reckon therefore that a guardian asteroid is our best option. And once we have such an asteroid in orbit, we wouldn't really want to lose it (we would probably have also made use of it to accommodate a space station, incorporating perhaps a Hubble-style telescope), so we are likely to try the nuclear option before we would have to rely on our guardian asteroid in any case (we have afterall rockets and nukes standing by). The guardian asteroid would therefore always serve as Plan B, as well as being a deliverer of hope, if/when scary times arrive. And to not make this post too long, I will refrain from mentioning bad old Murphey.

pyoko · Jul 14, 2007

I heard that Boeing has a team that is trying to figure out antigravity or something similar. Also, some experiments have been done with rotating superconducting disks, and the object above the spinning wheel was supposedly losing mass (but this has been disputed and put down to human error). <div class="Discussion_UserSignature"> -pyoko the duck It is by will alone I set my mind in motion. </div>

tony873004 · Jul 14, 2007

"Smaller pieces hitting us would certainly cause havoc and dispair" Not certainly. You would have to quantify that statement. Many small pieces would be no bigger than grains of sand. If 99% of the asteroid's original mass missed Earth, Earth would receive only 1% of the kinetic energy it would have otherwise received. But if there were large fragments that still posed a threat, we know exactly where they would be. They'd be on the asteroid's original trajectory since that is the trajectory that intersects Earth. Assuming that significant threatening fragments existed, we could deal with them the same way we dealt with the original asteroid. "Considering that we are doing nothing at the moment in this regard..." Actually, we are doing quite a bit to recognize and protect ourselves from previously unknown threatening asteroids. In the past 60 years we went from not even recognizing that a threat existed, to recognizing the threat, quantifying the threat (still lots to be done here). We've invented space-bound rockets, the techniques to navagite a payload to an asteroid (we've landed craft on 2 of them). We've invented nuclear weapons. And in recent years we've pumped up the effort to locate and characterize all threatening asteroids through programs such as Spacewatch, Near-Earth Asteroid Tracking (NEAT), Lowell Observatory Near-Earth-Object Search (LONEOS), Catalina Sky Survey, Campo Imperatore Near-Earth Objects Survey (CINEOS), Japanese Spaceguard Association, and Asiago-DLR asteroid survey (thanks Wikipedia

), as well as several amateur efforts such as the Shoemaker Grant. There's still a lot of work to be done, but we've definately started. The guardian asteroid idea is simply not realistic. The amount of force needed to significantly alter its position on moment's notice is magnitudes greater than the amount of force needed to directly deflect the incoming asteroid. Another problem is that we w

qso1 · Jul 15, 2007

fingle: Even with deflection as the goal, the bomba will need to impart a large amount of force. So some method of getting the most bang for the buck is desirable. Yes ? No ? Me: I'm not sure how much force would be required to nudge an asteroid of signficant size. There are asteroids that would be too large to be nudged sufficiently by any bomb in the megatonnage range tested so far. The largest device ever tested that we know of was the Tsar Bomba of Soviet Union design. Tested in 1961, this thing was thought to have been in the 57-92 megaton range. The shockwave circled the Earth 3 times according to the Guiness folks. Yet even this monster might not be enough to nudge a space rock tens of miles in diameter. As for bang for buck, I went into considerable detail for a book of mine as to a deflection scheme. But even that would be limited to asteroids up to a certain size and it does not include extreme sized warheads because no 57 megaton warheads are in production or service at this time. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

qso1 · Jul 15, 2007

fingle: It would be really great if it could be tested, what ever happened to the nuke that some scare monger claimed the deep impact mission had ? Me: Testing a nuclear device to deflect an asteroid would actually be relatively easy to do. The problem is budgeting such a mission. As for the Deep Impact mission carrying a nuke, I suspect that was more someone hypothesizing and coming up with a fairly credible scenario which caught on with the folks who do not realize how budgets impact mission plans and proposals. It certainly would have made sense to put a nuke on deep impact but it would also cost dollars. Dollars which are scarce enough as it is. And there is simply no hard credible evidence I'm aware of that a nuclear explosive was carried on that mission. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

scientists do not understand

tony873004

Guest

oscar1

Guest

tony873004

Guest

qso1

Guest

fingle

Guest

qso1

Guest

fingle

Guest

oscar1

Guest

nec208

Guest

kelvinzero

Guest

wize1

Guest

nexium

Guest

tony873004

Guest

oscar1

Guest

pyoko

Guest

tony873004

Guest

qso1

Guest

qso1

Guest

Similar threads

TRENDING THREADS

Latest posts

Share this page