Ideas to protect the Earth from possible asteroid impacts

[Mlesnita Daniel]

Do you have any own idea, on a way to protect the Earth from a possible asteroid impact?

(You can not use technologies that are not invented yet, or imaginary. Those that can be invented in the next, let's say, 10 years, are allowed)

 

[phinds]

Do you have any own idea, on a way to protect the Earth from a possible asteroid impact?

(You can not use technologies that are not invented yet, or imaginary. Those that can be invented in the next, let's say, 10 years, are allowed)

What ideas has your research found so far?

 

[mathman]

First things first. Detection long enough in advance is necessary to do anything.

 

[rootone]

Not really.
If the object is massive enough and it's trajectory intersects with Earth, it will do massive damage.
Ideas suchlike we could nuke it don't work, Earth still gets hit but by a bigger number of fragments.
That might make things even worse.
As pointed out by mathman though, if it was seen coming early enough, we might be able to push it away with rockets or something.

 

[pinball1970]

Do you have any own idea, on a way to protect the Earth from a possible asteroid impact?

(You can not use technologies that are not invented yet, or imaginary. Those that can be invented in the next, let's say, 10 years, are allowed)

Two projects have resulted in landing probes on asteroids Ryugu and Churyumov.
If they can do that now perhaps in 10 years they could land a manned mission?
Once we have scientists there, they can work out how to deflect it, whilst carrying out important work involving the formation of the solar system.
A sort of two birds one stone scenario.

 

[Justin Hunt]

The two main proposed methods are either ramming a spacecraft into the asteroid at high velocities or landing and setting off a nuke on the surface. Both method's goal is only to slightly nudge the asteroids trajectory and require enough lead time to be effective. There is still work being done to map out and discover every threat to the Earth that is out there in the solar system. Right now we don't have a solution if we only have a short time in advance notice such as the case in the movie Armageddon.

 

[NateTheGreatt77]

There is another idea which I think was in the movie Armageddon from '98. Instead of blowing up a nuke on the surface, you drill into it and blow it up from the inside. This way you split the asteroid and then the larger pieces will be pushed away from Earth without changing the momentum of the asteroid.

Obviously this would cause other problems like having radioactive asteroid pieces shooting towards Earth but its an interesting concept. There are some clips from the movie on Youtube that you can find that you might enjoy.

 

[Justin Hunt]

@NateTheGreatt77 movies are for entertainment and are generally very unscientific. There are numerous major flaws with that strategy such as the window being to small, the depth required to dig, what would actually happen when the nuke went off, the technical difficulties of bringing the tools to the surface and also actually drilling the hole. The two methods I mentioned previously are the only two known feasible ones right now.

 

[bahamagreen]

It is a gruesome question, so we may as well consider a third class of methods that desperately suggests moving the Earth to dodge the hazard. This class of methods would bear unimaginable consequences even if successful, the only consideration being the possible avoidance of Earth's complete destruction.

There might be two general proposals to accomplish this. One might be to move the Earth indirectly by displacing the Earth-Moon barycenter by directly moving the Moon, the other might be to move the Earth directly.

With sufficient lead time and planning, moving the Moon might be the more attractive approach of this class if the long term result is that the Earth stays near its present orbit. So, perhaps this is a series of thermonuclear detonations (possibly consuming the whole world's nuclear arsenal) at a region on the Moon, positioned and timed to induce the Moon to shift orbit and dislocate the Earth-Moon barycenter enough for the Earth to miss the hazard.

With less lead time and more panic, moving the Earth directly may be the much more desperate approach but one which is designed to keep the long term Earth orbit near its present orbit. So, perhaps this is thermonuclear detonations over a large region on the Earth's equator, the resulting revolving continental fire timed to push the Earth out of and back into orbit during one revolution, the thrust coming from the fire.

Forest fires release on the order of 1 megawatt per second per acre of fire area
The Amazon has 1.4 billion acres of forested area
An Earth revolution is 86,400 seconds
So, about 10^23 Watts

I guess about half of that power would be available to displace the Earth and the other half would be needed to put it back, but both shifts would be curved paths, the minimum displacement would need to be at least one Earth radius for "small" hazards, and would need to be further for hazards big enough to suffer tidal demolition... I wonder if, and how big (or how slow) a hazard could the Earth miss with that power..?

 

[256bits]

As pointed out by mathman though, if it was seen coming early enough, we might be able to push it away with rockets or something.

I think we had a posting here a while back where it was discussed if a person could push a big boat away from the dock, and with his tiny push compared to the mass of the big boat, it would be possible.
I have wondered though that with the new and improved orbit of the asteroid, how much time ( or orbits ) would it take for the earth-asteroid to intersect once more.
Maybe never.

 

[LURCH]

Nukes are the best way to go. I’m sure we’ve all heard the objections that using a nuclear weapon against a potential impactor will “turn one rock headed for the Earth into thousands of rocks headed for the Earth”. I hope that most people in these Forums can see the flaw in that statement.

The best course of action I can see would be a series of large thermonuclear devices, aimed at various points along the trajectory of the threat. As with any practical method of interception, early detection and accurate plotting are the key. If the first blast does break the object into many pieces, any of those pieces that are still on course to strike the Earth will pass through the later intercept points, and be hit again. The first strike should be a “bunker buster”, designed to punch a hole deep into the object before detonating. The follow-up blast could be the “stand-off” detonations often proposed for these scenarios.

 

[pinball1970]

Nukes are the best way to go. I’m sure we’ve all heard the objections that using a nuclear weapon against a potential impactor will “turn one rock headed for the Earth into thousands of rocks headed for the Earth”. I hope that most people in these Forums can see the flaw in that statement.

The best course of action I can see would be a series of large thermonuclear devices, aimed at various points along the trajectory of the threat. As with any practical method of interception, early detection and accurate plotting are the key. If the first blast does break the object into many pieces, any of those pieces that are still on course to strike the Earth will pass through the later intercept points, and be hit again. The first strike should be a “bunker buster”, designed to punch a hole deep into the object before detonating. The follow-up blast could be the “stand-off” detonations often proposed for these scenarios.

Would a base on the moon be better for this?
Assuming money was available? Less gravity and friction for launching?

 

[LURCH]

I was actually thinking of the devices in orbit around the Moon. Final assembly would take place in that orbit, just to avoid some of the political obstacles to the plan. Once the threat is detected while still many years away, the launch (escape burn, more specifically) could be timed to whatever moment is most advantageous, using the Moon’s motion to speed the devices on their way.

Much of the problem with using nukes is the fear that the one controlling the devices might decide to use them against someone here on Earth. This eliminates that threat, since any attack would take days to arrive.

 

[pinball1970]

I was actually thinking of the devices in orbit around the Moon. Final assembly would take place in that orbit, just to avoid some of the political obstacles to the plan. Once the threat is detected while still many years away, the launch (escape burn, more specifically) could be timed to whatever moment is most advantageous, using the Moon’s motion to speed the devices on their way.

Much of the problem with using nukes is the fear that the one controlling the devices might decide to use them against someone here on Earth. This eliminates that threat, since any attack would take days to arrive.

Yes It would have to be a global collaboration money wise and security wise.

If they can put together funds and technology for the James Webb then a missile station in orbit must also be possible

 

[Justin Hunt]

If you are going to make space installations I would think something like a rail gun would be more practical (potentially with nuclear rounds). It could be solar powered and store the energy over long periods of time. The biggest Issue i can see is that the shots would alter its course. maybe on the surface of the moon may work better. But, that is a rather expensive investment for something may never be used or may not even be very helpful when it is used.

 

[unusually_wrong]

It all depends on the size, what it's made of, and how soon we detect it. Nukes would be entirely useless against an asteroid the size of Ceres.

 

[davenn]

Nukes are the best way to go. I’m sure we’ve all heard the objections that using a nuclear weapon against a potential impactor will “turn one rock headed for the Earth into thousands of rocks headed for the Earth”. I hope that most people in these Forums can see the flaw in that statement.

ohhh ... I would love to hear your opinion/reason

 

[nikkkom]

It is a gruesome question, so we may as well consider a third class of methods that desperately suggests moving the Earth to dodge the hazard. This class of methods would bear unimaginable consequences even if successful, the only consideration being the possible avoidance of Earth's complete destruction.

There might be two general proposals to accomplish this. One might be to move the Earth indirectly by displacing the Earth-Moon barycenter by directly moving the Moon, the other might be to move the Earth directly.

What are you talking about?? Moving either the Earth or the Moon by even a microscopic amount is totally beyond our capabilities in the next few thousands of years. Moving an asteroid is way more practical.

 

[nikkkom]

Not really.
If the object is massive enough and it's trajectory intersects with Earth, it will do massive damage.
Ideas suchlike we could nuke it don't work, Earth still gets hit but by a bigger number of fragments.
That might make things even worse.

Why this idea that "nukes wouldn't work" persists for so long? Try doing some back-of-envelope math. Nukes seem to work, unless we talk about 10+ km sized objects.

 

[rootone]

... unless we talk about 10+ km sized objects.

That is what I thought we were talking about.
Sure enough, if it was a 1 km meteor, a nuke could do the trick.
Then again, a 1 km object would probably not be seen in time to anything about it.

 

[nikkkom]

Then again, a 1 km object would probably not be seen in time to anything about it.

?!

The NASA Authorization Act of 2005 required the detection of 90 percent of NEOs of 140 meters (around 459 feet) or larger by 2020. Even though it seems that NASA will miss that tight target, the coverage of 1+ km sized objects is already better than 90%:

https://cneos.jpl.nasa.gov/stats/

"With over 90% of the near-Earth objects larger than one kilometer already discovered, the NEO Program is now focusing on finding 90% of the NEO population larger than 140 meters"...

 

[rootone]

I'm sure a that a 1km object could be seen, but probably only when actually near to Earth, leaving insufficient time to do much about it.

 

[nikkkom]

"Discovered" in that legislation means "orbit known with high precision". This means that positions of almost all hazardous 1+ km asteroids are already known for decades in advance.

 

[Vanadium 50]

The NASA Authorization Act of 2005 required the detection of 90 percent of NEOs of 140 meters (around 459 feet) or larger by 2020.

Politicians require lots of things.

The City of Berkeley, for example, requires that nothing radioactive - even a single disintegration - enters the city limits.

 

[256bits]

It all depends on the size, what it's made of, and how soon we detect it. Nukes would be entirely useless against an asteroid the size of Ceres.

What is it - 9 months to get to Mars and that's Mars and Earth on a good time.
One could use a bigger rocket and decrease the time.
Then there is the question - Where is the best place to hit the asteroid? A lot of then are clunky, with an uncertain interior composition, and sore spot.
Seems like a lot of room for failure just right there - failure including leaving a large chunk still heading to Earth after a successful hit.

 

[nikkkom]

Then there is the question - Where is the best place to hit the asteroid? A lot of then are clunky, with an uncertain interior composition, and sore spot.
Seems like a lot of room for failure just right there - failure including leaving a large chunk still heading to Earth after a successful hit.

Surface or near-surface blast may be preferable, it has a more predictable effect - part of asteroid is ablated away, pushing the entire remaining asteroid, still in one piece. Especially if you have even just an approximate control over the location of the blast and thus, the direction of the push, this is a nice, controllable deflection rather than "let's go with a big BOOM and hope for the best" approach.

 

[Ratman]

Surface or near-surface blast may be preferable

Absolutely! Deflection in one way or another is the only reasonable way of dealing with that threat. Hollywood's idea of nuking the asteroid into zillion pieces is fun and entertaining until you realize that the center of mass of resulting cloud of debris is still coming towards you. It may be unable to produce a huge crater, but it will affect much larger area in multiple impacts (reminder: you need only 20 m diameter asteroid to get Chelyabinsk-like fireworks), and don't forget that all that debris falling into the atmosphere over the continent(s) is now highly radioactive. Thank you Bruce Willis.

 

[256bits]

Surface or near-surface blast may be preferable, it has a more predictable effect - part of asteroid is ablated away, pushing the entire remaining asteroid, still in one piece. Especially if you have even just an approximate control over the location of the blast and thus, the direction of the push, this is a nice, controllable deflection rather than "let's go with a big BOOM and hope for the best" approach.

Any chance the shock wave, from a pretty much instantaneous heating zone of solid to liquid and gaseous, passes through the asteroid and blows out some material from the far side, negating the push from the vapourization on the near side. In fact, the main body of the asteroid could be "sucked" towards the blast from that effect, rather than away if that effect predominates. Has that been investigated at all?

 

[nikkkom]

don't forget that all that debris falling into the atmosphere over the continent(s) is now highly radioactive. Thank you Bruce Willis.

Completely negligible, considering the magnitude of catastrophe humanity is trying to prevent in this scenario.

 

[nikkkom]

Any chance the shock wave, from a pretty much instantaneous heating zone of solid to liquid and gaseous, passes through the asteroid and blows out some material from the far side, negating the push from the vapourization on the near side.

I imagine pretty much any type of asteroid has surface layer of dusty fractured regolith, similar to what Moon has. It does not transmit shocks well.