Killer Asteroids

[JohnC]

With all the handwringing concerning what we should do if a large asteroid threatens Earth, I have a pretty simple idea. Embarrassingly simple.

The Japanese have already demonstrated we have the technology to land a spacecraft on an asteroid, so, we land one or more relatively small spacecraft on the asteroid, rotate the landing engines 180 degrees, fire them up, and literally push the asteroid into another trajectory.

Please spell my name correctly on the check, Mankind.

Edited May 19, 2014 by JohnC

[Mordred]

great now how did you anchor to the asteroid? in other words what is the composition of the asteroid? if its ice and rock have fun.

if you fire the jets you now have a spinning asteroid, may or may not change its course

 

F=MA how much force will your jets need to move that asteroid?

 

how early do you need to spot the asteroid in order to get everything ready for the rocket to leave Earth, arrive at the asteroid, anchor to the asteroid and deflect its course. How many jets will you need to maintain a stable non induced rotation? 2, 4? One won't then you also have the problem of synchronizing the rocket jets so they don't induce rotation.

 

Not to say your idea won't work, but there is an easier way assuming you have enough time. Simply place spaceship/rocket in orbit around the asteroid always facing between the asteriod and desired angle of deflection. Your ship will have a gravitational attraction to the asteroid and vise versa. Use your rockets to just maintain your position. Eventually the course will change. However in order for this to work you need a lot of prewarning. NASA already studied this idea as well as your rocket idea. So you probably won't get a paycheck

 

forgot to add NASA has numerous ways to deflect an asteroid, the problem is the composition, mass and rotation of the asteroid and how much warning we have.

Edited May 19, 2014 by Mordred

[CaptainPanic]

That idea has existed for a long time, as shown in this article (check the 6th idea how to move an asteroid), so I am not sure this is gonna make you rich.

 

The core of the problem in moving an asteriod is how to move it the most with the least effort. The problem with your idea is that you need to bring enough propellant to move it. And while it is easy to bring a rocket to an asteriod, it is a lot harder to bring the necessary fuel tanks and fuel (look for example at modern rockets: the large majority of any rocket is just the fuel tanks). This is why people now look at using mirrors to heat a part of the asteroid, so that the evaporating gases will be the engine and move the asteroid. Using the sun's power, the space craft won't have to carry all that propellant with it.

[Delta1212]

I suppose Indiana Jones could have avoided that sprint through the temple if he'd just thought to divert the boulder around him by blowing on it.

[Enthalpy]

Engineering is all about figures. How much propellant, how big the geocruiser?

[Airbrush]

A direct method of deflection is best in that is saves time. We can be blind-sided by a city-killer, or worse, at any time. Simply smacking against it with a good mass is fail safe. I would design a huge net that opens just before impact to soften the blow, spreading its' mass over a large area. This would work on asteroids of most consistencies. I don't know about the "cotton-candy" fluff balls.

 

If it is a solid rock, launch a series of nukes rockets at it to explode just far enough away to heat up one side to out-gass.

 

After you have such direct-method deflection methods up and running, you can work on better indirect methods, such as gravity tractors or landing rockets all around the asteroid as the op suggests, which is a very good idea, if you have the luxury of a long lead time.

Edited May 19, 2014 by Airbrush

[Enthalpy]

Once again: how big the impactor, at which velocity, to deflect what size of geocruiser? How big the launcher?

 

Because, figure that out, these are the questions that stop the experts from answering "we know how to do". Picking their list of research directions, of which experts know they're impratical, and adding your priority sequence based on unjustified reasons, brings little.

[Airbrush]

Once again: how big the impactor, at which velocity, to deflect what size of geocruiser? How big the launcher?

 

As big as practicable within cost constraints. First you build impactors that will be effective on smaller objects, and later you work on bigger, and thus more costly, deflectors that will be effective on larger objects. After that, you design indirect systems that will work on objects that won't hit us for decades.

[EdEarl]

The size of an asteroid or comet makes a big difference in what you must do. The largest thing ever to hit the Earth was very large, maybe the size of Mars, and it made the moon in the aftermath. The smallest things are subatomic particles. One might be so big-fast there is nothing we can do. Most things that hit the Earth don't affect anyone. At this time there are some things we can affect favorably. In the future, we should be able to deflect larger objects and see them further away; thus, we should expand our capability. But, there are some catastrophes that we cannot avoid; for them we need a colony elsewhere.

[Delta1212]

 

As big as practicable within cost constraints. First you build impactors that will be effective on smaller objects, and later you work on bigger, and thus more costly, deflectors that will be effective on larger objects. After that, you design indirect systems that will work on objects that won't hit us for decades.

And to defeat modern encryption, all you need to do is build a computer fast enough brute force any password in a few seconds.

[BearOfNH]

And to defeat modern encryption, all you need to do is build a computer fast enough brute force any password in a few seconds.

 

Good, but I betcha an Indiana Jones riff would have gotten you some +1s.

[Airbrush]

And to defeat modern encryption, all you need to do is build a computer fast enough brute force any password in a few seconds.

 

What does this have to do with the topic "Killer Asteroids"?

[Delta1212]

 

What does this have to do with the topic "Killer Asteroids"?

Saying that "all we need to do is build something that can solve the problem" ignores the fact that it's only considered a problem in the first place because building that something is an incredibly difficult piece of engineering that in many cases may not even be physically possible let alone practical to implement.

[Airbrush]

Saying that "all we need to do is build something that can solve the problem" ignores the fact that it's only considered a problem in the first place because building that something is an incredibly difficult piece of engineering that in many cases may not even be physically possible let alone practical to implement.

 

The fact is that if we don't start building defense systems, we may suffer for it IF we get unlucky during the next century. Something can be done soon to mitigate the threat of city killers. Globe killers just take longer to defend against. There is a big difference between city killers and planet killers, and a whole range of sizes in between. We can do something about events that occur once in a few hundred years, during the next few decades. Events that occur once in a few million years can be delt with later. Don't make the assumption that all that matters is defending against planet killers.

Edited May 31, 2014 by Airbrush