It is possible to detonate a nuclear bomb in space, if possible then what will happen? In Armageddon movie we watched that, after discovering that an asteroid the size of Texas is going to impact Earth in less than a month, NASA recruits a team of deep core drillers to drill and blast a nuclear war-head. Is it possible?
You can detonate nuclear bombs in space, it's been done several times. There are technical challenges to it but nothing too complex.
In an atmosphere much of the damage from a nuclear weapon is from the blast wave which is caused by the heat and pressure of the explosion. This wave goes out from center of the explosion, and then back again as the pressure drops. This is why most nuclear weapons are designed for an air burst rather than a surface burst in order to maximize the destruction caused.
A nuclear weapon in space has a different effect than one detonated in the atmosphere or underground as there's no matter for the explosion to push against. What will happen is a burst of radiation and plasma which disperses evenly outward from the detonated device.
What would happen if you detonated a nuclear device inside an asteroid? That depends on the composition an size
- If it's small enough it could be completely vaporized, however if it's that small it's probably not a danger
- It could blast it into many pieces, which would be a bit better than one big asteroid as it gives the smaller pieces a better chance of burning up in the atmosphere, although the earth would get pelted by many smaller impacts rather than one big one, spreading damage over a wider area
- The asteroid could contain the blast and remain intact, or the force of the explosion could be lost through fissures in the body of the asteroid and also leave it intact. It is extremely unlikely that it would break into 2 clean pieces predictably as in that (awful, awful) movie.
A nuclear blast theoretically could be used to deflect an asteroid by being detonated close to it, the heat and radiation could ablate the side of the asteroid facing the explosion causing it to change course. The effect is likely to be small and would need to be achieved while the asteroid is a considerable distance away. We would need many years' warning to achieve this, which is why it is pretty important that we start tracking asteroids and comets far better than we do now.
Is it possible?
As depicted in that awful movie? No. The concept in general? Yes. A nuclear standoff explosion is widely regarded as the best, most realistic approach to diverting an incoming asteroid or comet, assuming some minimal amount of lead time. Weeks or months do not qualify as "minimal". We need a couple of years, at least, even with nukes.
A nuclear standoff explosion involves exploding a nuclear bomb at some distance away from the target object. (Note well: This is exactly how our every country that has nuclear weapons plans to use them, and has tested using them. This is a Technology Readiness Level 9 concept.) More than half of the radiation and neutrons created by the explosion go off into space, but a good portion will bathe the asteroid/comet with gamma rays, X-rays, and high energy neutrons. This will cause the outer layer of the part of the asteroid/comet that faces the bomb to vaporize. It is this secondary explosion that provides the needed impetus to divert the object.
We cannot divert all incoming objects. The asteroid that exploded over Chelyabinsk in early 2013, or a dinosaur killer comet that we don't see until months prior to impact: Those are problems for some future generation to solve. Those Chelyabinsk-level objects are far too hard to see. Diversion is not possible if we can't see the incoming object ahead of time. Suppose a dinosaur killer by some fluke of its trajectory manages to sneak up on us until just months before impact. We're already dead. At some point there is nothing we can do except say goodbye to one another.
What we can solve using current technology, or reasonable extensions to current technology, are potential impactors that we first detect years prior to the impact. The nuclear option is the only viable approach if we detect the impactor less than a decade prior to impact. With that short of a lead time, a non-nuclear approach would require hundreds to millions of launches and hundreds to millions of cooperating vehicles. A nuclear approach would require very few launches, typically, just one.
Non-nuclear approaches might work if we detect the impactor several decades prior to impact and if we take action soon after detection. That action includes spending a rather sizable chunk of money on technology that is not quite ready for prime time, and that spending needs to start soon after detection. The problem here is that that multiple decades of lead time is more than enough time for the uglier side of humanity to raise its ugly head. "Why should we spend such huge amounts of money to solve a problem that won't be a problem for half a century when we have so many pressing problems right now?" So we won't spend the requisite amounts of money. We'll instead twiddle our thumbs. We'll wait and wait until the problem is a decade away or less, making the nuclear option the only viable option.