An asteroid impact could wipe out an entire city — a space security expert explains NASA's plans to prevent a potential catastrophe

Catastrophe

"Science begets knowledge, opinion ignorance.
"To date, NASA has tracked only an estimated 40% of the bigger ones(opens in new tab). Surprise asteroids have visited Earth in the past and will undoubtedly do so in the future. When they do appear, how prepared will humanity be?"

"What is Planetary Defense?
Planetary defense is the term used to encompass all the capabilities needed to detect the possibility and warn of potential asteroid or comet impacts with Earth, and then either prevent them or mitigate their possible effects. Planetary defense involves:
  • Finding and tracking near-Earth objects that pose of hazard of impacting Earth;
  • Characterizing those objects to determine their orbit trajectory, size, shape, mass, composition, rotational dynamics and other parameters, so that experts can determine the severity of the potential impact event, warn of its timing and potential effects, and determine the means to mitigate the impact; and
  • Planning and implementation of measures to deflect or disrupt an object on an impact course with Earth, or to mitigate the effects of an impact that cannot be prevented. Mitigation measures that can be taken on Earth to protect lives and property include evacuation of the impact area and movement of critical infrastructure."
Cat ;)
 
I prefer the plan of the late Dr. Edward Teller i.e.: "shoot them or vaporize them with nukes". Personally, I wish such a capability was currently in place and fully manned by "Trigger Happy" types. I would willing pay more in taxes for such. Admittedly, this overt aggression on my part is likely a personally flaw, but then I like guns and technical weapons that "go boom". It gives a tentative sense of security. For a sobering analysis, read : "The Ends of the World" by Peter Brannen.
 

Catastrophe

"Science begets knowledge, opinion ignorance.
sam85geo,

There is no single simple solution. The "target" can vary greatly and react in a variety of ways.
For example you can have two ends of a scale. There is a lot of detail in the Asteroids - Agreed Terms thread - take, for example, iron meteorites. Asteroids themselves, are not very amenable to study, but we have lots of the pieces resulting from collisions, luckily (in most cases) delivered to us here on Earth as meteorites.
So-called iron meteorites consist almost entirely as iron/nickel, and some have differentiated, which means that they have melted and aggregated in the centre - later to be broken apart by collision. How uniform is the molten core (subsequently solidified)? What will be the result of a percussive hit? Will it react as a single body or are there planes of fracture?
At the opposite end of the scale there may be large simple aggregates. We can tell the proportion of low density "targets" and it is quite high. Depending on what you hit it with, it may explode into zillions of little bits (great meteor showers) or pass straight through.
At what angle are you going to hit it? Full on? Perpendicular - how you you plot impact course? Probably the best is at an angle from full on, i.e., approach at 5 or 10 degrees from full on. This will also slow down target a little - but before cheering too loudly look at conservation of momentum. The average case may resemble hitting a 20 ton truck, travelling at 100mph, with a rolled up newspaper.

No, do not think that a nuclear bomb will be the panacea of all ills. Before anything you need to know the course, momentum, mass (separately), and composition.
Although the Late Heavy Bombardment may be over, there is a billion year future of comets detaching from the Oort Cloud and heading inwards, not to mention perturbations of members of the Asteroid Belt to form more and closer Near Earth Objects.

Charge in, guns blazing, and all may be well. But, where ignorance is bliss , , , , , , as the old saying goes. At least prime your bombs with investigation. And a lot of preparation will have to do with getting your approach path sorted - and 100% accurate.

Cat :) :) :)
 
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Apr 29, 2022
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Even if we targeted them with nukes, The assorted fragments would destroy major areas around it. And also in space the Nuclear arms would not have as big of an impact because their shock wave would not be as large.
 

Catastrophe

"Science begets knowledge, opinion ignorance.
The truth is that we have only mapped a proportion of Near Earth Asteroids.

How frequent are near misses, and how soon before a not so distant hit?

Bombardments, as with dinosaur time, may be a thing of the past, but what about comets or other objects diverted from the Oort Cloud? What do we know about these? Are they not too far out to observe?

Cat :)
 
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Catastrophe

"Science begets knowledge, opinion ignorance.
Don't forget that the volume of space which has to be monitored for NEAs* increases with the cube of the radius - the distance from Earth. And it gets more difficult to observe small relatively dim objects. *Near Earth Objeects.

Cat :)
 
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OK; I just learned a bit to markedly modify my "shoot em up" approach to interdicting space rock devastation. Basically, there is no "sure shot" solution to the apprehension about an ELE asteroid/comet strike. Presently, considering the massive taxpayer and debt funding being diverted into the sustaining of the current political warfare, which seems to eschew meaningful negotiations by all involved parties, the salient "devastation" akin to space rocks appears to be from people not asteroids and comets.
 
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Here's a reference which may provide valuable insights in any emergency. "When There Is No Doctor" by Gerard S. Doyle, MD. Likewise, consider that emergencies, natural or man made, pose moral dilemmas of providing for family first while others have to be excluded. "Reasonable" preparation and planning seem logical for all. One data source for emergency preparedness preparation is the U.S. FEMA web site.
 
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