Airbrush

Yes, that's how it works. There are no shock waves in the vacuum of space. I have no reference; it just makes sense. You disagree? If you explode the nuke close enough it will melt the area facing the blast, cause outgassing (and a push), and quickly solidify because space is cold. If you explode a number of nukes close enough, each one will melt, fuse, and freeze rock, metal, and ice. You just keep exploding the nukes on the same side so you can push it in the same direction. Why not?

It doesn't get blown up. There is only an intense, very short, pulse of HEAT, no shock wave in space, that should melt any rocks or ice and they would immediately freeze again but fused together, and it gets a push from outgassing.

Y A A A A A Y ! ! ! !

That would be a good thing! It is not in the news that much is being done to develop a way to divert asteroids. Do you know of any such projects? Tell us about it! I think it would be a good thing to develop deflection methods, using whatever money is available, public or secret. "Coalesce due to gravity" would be a good thing. "Rain down radioactive material" wouldn't happen if done far away from earth. The "impact of politics" would need to be addressed. IF nukes are a good way to divert a wide range of composition and sizes of asteroids, then it would have to be made public and discussed. IF scientists could convince the world that the way to save earth would be by using nukes, then that method should be promoted and explained to the world.

I haven't heard a reason why a nuclear explosion near an asteroid would not work on ANY composition of asteroid, and a RANGE of sizes, but maybe not the largest ones. Do you know any reasons it would not? If you learned that an asteroid that will destroy a city, or a country, or life as we know it, would you not care? What composition of asteroid would a nuclear explosion not give a push? Also, loose rubble piles may be fused by the heat pulse, and thus keep it together while it gets pushed! I don't know if it will, but why not? You don't believe in secret, or black projects? I don't understand how what I posted about black budgets is "snarky." Can anyone explain?

When do you think we may hear in the news that a group of scientists and engineers are working on ways of diverting asteroids of various sizes, compositions, and times to impact, using supercomputers? And maybe they have a secret budget of a billion dollars, right? And they will reassure us in the near future that they have ideas for all sorts of ways to divert them in the near future, right? Apophis is 1,200 feet wide and is passing by earth in 2029. Does anyone know of any missions to this? Maybe an opportunity to slap it with a kinetic impactor to see the effects. The most efficient diversion method is one that will work on ALL compositions of asteroids, and it works on a range of sizes. When asteroid Apophis makes its close approach to Earth on April 13, 2029, it will be traveling at a speed of 18 miles per second relative to Earth. 99942 Apophis - Wikipedia

"Diverting an asteroid can be approached using various methods, each with its own timeframe for effectiveness. Among the methods you mentioned—gravity tractor, direct kinetic impactor, and nuclear explosion near the object—the gravity tractor would generally take the most time to work. Here’s a comparison of each method: Gravity Tractor: Mechanism: A spacecraft hovers near the asteroid, using its gravitational pull to slowly alter the asteroid’s trajectory over time. Timeframe: This method requires a prolonged period to have a significant effect, often taking years to decades to produce a noticeable change in the asteroid's path. The effectiveness depends on the mass of the spacecraft, the proximity to the asteroid, and the duration of the operation. Direct Kinetic Impactor: Mechanism: A spacecraft or projectile is deliberately crashed into the asteroid at high speed to impart momentum and alter its trajectory. Timeframe: The kinetic impactor method can produce more immediate changes compared to a gravity tractor. The effect on the asteroid’s trajectory occurs at the moment of impact, but the degree of change depends on the mass and speed of the impactor and the asteroid’s characteristics. While it acts relatively quickly, achieving significant deflection might still take years, depending on the warning time and required trajectory change. Nuclear Explosion Near the Object: Mechanism: A nuclear device is detonated near the asteroid to vaporize part of its surface, creating a jet of debris that propels the asteroid in the opposite direction. Timeframe: A nuclear explosion would result in a rapid and significant change in the asteroid's trajectory. The explosion causes an immediate reaction, potentially providing a substantial deflection in a short period. However, precise control of the outcome is more challenging compared to other methods. In summary, the gravity tractor method takes the longest time to work among the three, as it involves a slow and gradual alteration of the asteroid’s trajectory over an extended period. The kinetic impactor acts faster but still requires a relatively longer timeframe compared to a nuclear explosion, which can achieve immediate and significant changes." - ChatGPT

Depending on the size of the rubble pile, a kinetic impactor can blow it to pieces, and if that happens far enough away, it will scatter the pieces far and wide so only a few tiny pieces may make it to earth, if any do.

Depending on the size and composition of the object, a big enough lump of lead traveling at a big enough speed could be very effective against the smaller objects, even rubble piles. Velocity is squared so twice the speed means 4 times the KE. If you hit a solid metal or rocky object far enough away a tiny impact may be enough to change its' course to miss earth. If you hit a rubble pile far enough away, you may scatter the fragments so wide that only a few small pieces will make it to earth. Discussion about saving the world from destruction may be emotional. 1 The technology needed for a gravity tractor takes more engineering, cost, and time, than a direct method like hitting it with a mass or exploding a nuke nearby. How much more time I don't know, but I think it would be significant. 2 We don't know when we might spot an asteroid, but after you do spot it, you hope you have time to do something. 3 Do you think it is worth trying to develop a 100-megaton bomb when we have thousands of smaller nukes. "...the US likely has around 100 nuclear warheads with yields of at least one megaton, primarily in the form of the B83 bombs. This number is a rough estimate and may change due to ongoing disarmament efforts and modernization programs." - ChatGPT If you have 100 warheads that yield at least one megaton, that sounds like enough individual impacts to address most threats. No mention of comets so far, why not? Because comets come from ANYWHERE, not just the plane of the solar system, and are much harder to detect.

It seems to me an indirect method as a gravity tractor, will take much longer to put into action, than a direct method of launching a series of strikes on the asteroid. At least get a few rocket nukes on their way to the object. We don't know how much time we have. We don't want to be late in saving the world from massive destruction. There is no 100-megaton nuke. Tzar Bomba was less than 58 megatons. Better to send what we already have thousands of small nukes to "fine-tune" changes to the object's trajectory. You blast it with one and measure the response, then hit it with another. It will be rotating, but that's ok, just keep pushing it in the same direction.

Obviously, humanity would use the nukes that are available, which already exist, and are plenty powerful and numerous. Nobody will try to create a 100-megaton nuke for this project.

Yes, find a rubble pile out in the asteroid belt and experiment fusing them with nukes. That is far enough away. People will complain about launching such a rocket. Would there be any risk of it accidentally exploding and scattering radioactive material in the atmosphere? It would not be an accidental nuclear explosion, right?

There would not be a shock wave. It would be just an intense, short pulse of heat. ChatGPT says: "The distance of the explosion from the asteroid and the yield of the nuclear device would be crucial. For rock fusion to occur, the heat and energy must be sufficient to melt the surface material. If the explosion is too far or the yield is too low, the energy might dissipate without causing significant melting." "In theory, a nuclear explosion could cause surface melting and outgassing, potentially pushing a "rubble pile" asteroid. However, the practical implementation of such a strategy would require precise control over the explosion's distance and yield, careful consideration of the asteroid's composition and structure, and strategies to mitigate the risk of fragmentation. More research and testing would be necessary to evaluate the feasibility and safety of such an approach."

There are 3 things necessary to intercept an asteroid: find them early, find them early, and find them early. We don't know when, so we need to think of a method than can be put into action sooner than gravity tractors can. How far away CAN we send nukes to intercept? As far as you can send them. So again, you need to find them early so you have time. Also work on gravity tractors, in case we have hundreds of years to prepare, but they will take a lot longer to be ready for action, and we may not have that much time. If you break it apart far away, the pieces will fly apart, but I am wondering if a nuclear blast, at the correct distance, would melt and fuse loose material together, and it would not break apart a rubble pile.

Correct me if I'm wrong, but most, if not all, asteroids are spinning. A single nuclear pulse will last a fraction of a second, so the outgassing will last only seconds. So, I believe outgassing will push for only a second. Am I wrong? Gravity tractors are an indirect method while a series of nuclear explosions in its' path works directly, thus mission accomplished sooner. That is interesting having fuel reserves in space to somehow dock with the gravity tractor(s). That will take a lot more time than nukes, and we DON'T HAVE TIME.

What is cheaper, to send a very massive object far away, with enough fuel for extreme, 180 degree, course changes, and enough fuel to keep pushing the tractor away from the object, and is massive enough to have an effect, OR to send a series of low-mass rockets, each with a single nuke and just enough fuel to accelerate to a very high speed to meet the asteroid as far away as possible? Having many small missions acts as a fail-safe. Having many gravity tractor seems much more expensive. Mission accomplished by nukes years before a gravity tractor even gets started.

You will need rockets that are designed to escape earth. What will happen to ANY asteroid composed of anything, metal, rock, ice, rubble pile, cotton candy, or all those combined, when you explode a nuke at the correct distance from the asteroid? There will be an intense pulse of heat for a fraction of a second. What will that do? It will melt, blister, fuse, cause outgassing, and explode volatiles, amounting to thousands of tiny rockets pushing in the same direction. This will push the pile a tiny bit without breaking it up. If you have a few hundred of these explosions, to make sure you have enough, you can fine tune for maximum course change. This is way cheaper and faster to accomplish, than gravity tractors. We have thousands of nukes. We just need the technology to deliver them into the path of the asteroid.

Because you need to intercept the asteroid when it is still very far away from earth, so a tiny push will add up to a major course change. Very far away from earth is a safe place to explode nukes. Gravity tractors are not effective against very large objects, because you need a lot more time to speed head-on at the asteroid, then decelerate to zero and accelerate to match the speed of the asteroid, which is moving about 10 miles per second. How much fuel will that take? After you are done with these fuel-expensive maneuvers, you still need a big mass to be effective.

Just reasoning that a gravity tractor takes a lot more engineering and time than a direct attack. I asked ChatGPT and here is what I got: "In summary, gravity tractors are effective for deflecting asteroids up to about 300 meters in diameter. Larger asteroids might still be influenced, but the effectiveness diminishes, necessitating longer mission durations and potentially additional deflection methods."

A gravity tractor requires sending a substantial mass to intercept the path of a small asteroid, but it also has to change direction by 180 degrees so it can fly alongside the asteroid. That takes a LOT of fuel to slow down, stop, and accelerate to match the speed of the asteroid. More efficient to directly smack it with something either massive or a series of nuclear explosions. We already have thousands of nuclear bombs.

Can a 10 km wide asteroid be a "rubble pile"? However, composition shouldn't make any difference. A series of nuclear explosions in the path of ANY 10 km wide asteroid will do two things: it would fuse together any loose rocks facing the explosion, and cause outgassing with each explosion. ENOUGH of these explosions, at the correct distance, can change its' course enough to miss earth. Why not? Remember, it won't get here for 100 years.

Suppose we discovered a 10 km wide asteroid that will definitely impact Earth in 100 years, what method of asteroid deflection would humanity use?

Yes, and I was wondering if a nuclear explosion at the perfect distance from the object to cause outgassing, nudging it, and not break apart a rubble pile? Maybe the intense heat from the explosion, at the perfect distance, would fuse the rocks together while also giving them a push. Then continue with as many explosions as it takes to cause enough of a course correction to miss earth.

Will a series of nuclear explosions in the path of a giant asteroid be enough to cause outgassing that will push it slightly, and without breaking apart a rubble pile?

What if it is a rubble pile? The "cable net" idea will work with any kind of smaller asteroids, but don't do the deceleration as someone suggested. Just open the net wide and crash into the rubble pile or rock with whatever mass is available. Of course, the "cable net" idea works only for smaller asteroids. For one 10km wide you better discover it many years before impact. How do you deflect a 10km asteroid?