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Neil deGrasse Tyson On How To Stop a Meteor Hitting the Earth
An anonymous reader writes "Astrophysicist Neil deGrasse Tyson talks stopping extinction-level meteor hits: '...Here in America, we're really good at blowing stuff up and less good at knowing where the pieces land, you know...So, people who have studied the problem generally – and I'm in this camp – see a deflection scenario is more sound and more controllable. So if this is the asteroid and it's sort of headed toward us, one way is you send up a space ship and they'll both feel each other. And the space ship hovers. And they'll both feel each other's gravity. And they want to sort of drift toward one another. But you don't let that happen. You set off little retro rockets that prevent it. And the act of doing so slowly tugs the asteroid into a new orbit.'"
The Dr Phil of astrophysics.
"The average reporter we talk to is 27 years old......They literally know nothing." - Ben Rhodes
that feel when you're feeling another's feel in space
Reads more like an article on his talking about How other people talk about stopping one from hitting the earth.
The blast from the little retro rockets hitting the much larger asteroid, will cancel the whole thing out - every action having an equal and opposite reaction and all that pesky old Newtonian conservation of momentum stuff...
Excuse me, but please get off my Pennisetum Clandestinum, eh!
You can keep your fucking emo asteroids. Go feel somewhere else and cut your wrists for real while you're at it. Remember down the road not across the street.
Seven puppies were harmed during the making of this post.
The "pull" between a spaceship and an asteroid would be equal to the apparent weight of the spaceship on its surface, decreased by the square of the distance between the two objects. This would reduce the traction to a very limited amount.
You'd get better results with a cable from the ship attached to the surface, but the problem would be the rotation of both objects.
To do a decent job, the spaceship would need to collect a large quantity of mass before attempting to drag the asteroid.
Speaking as an non American can I say that you are really REALLY good at blowing stuff up and shooting stuff too.
We blow shit up so well is because we understand that accuracy by volume is the best way to hit your target. What makes this guy think anyone's going to meet up with an asteroid traveling at who knows what speed.
Maybe I'm having a hard time understanding what he's talking about, but this sounds like a violation of Newtons III at a glance. Suppose you have an asteroid in space, and a rocket beside it. The asteroid attracts the rocket, and likewise the rocket the asteroid. For the rocket to "tug" the asteroid away, it will have to use some sort of propulsion, and all we really have are momentum-exchange drives - rockets, ion-thrusters, ect. To move, it must thrust with a larger force than the force of gravity, in exactly the opposite direction of the gravitiational force vector. The problem is, those particles used for thrusting the rocket, will impact the asteroid as well, assuming the asteroid is large enough to worry about moving. Even worse, some of them may even recoil! Wouldn't this absorbtion of momentum of the ions, gas, ect, undo the "tug" of the rocket in the first place?
That's what stopped that meteor in Russia.
Pretty sure this solution was given... decades ago.
Come on people, we need to mix up our delusions! It's more fun that way!
Or alternately, how big will the spaceship need to be? How quick would the space ship need to be for gravity to have any impact? Would it work on an asteroid couple of miles across, moving at say 25km a sec, which I am told is the average orbital speed?
More questions than answers I say.
The Neil deGrasse Tyson of Psychology.
If you are going to use this method, then the more mass in your ship the better. Unfortunately, that means a more expensive launch. If you plan ahead, you figure out a way to accumulate debris and smaller rocks at some stable orbital point so when you need mass you can launch a light ship, go to the rockyard, and gather up more mass at reduced cost.
If Slashdot were chemistry it would look like this:Cadaverine
Sure. Use rockets to get away from a close objet in vacum. Gravity is square root of distance and you use reaction engines is space. You see the pbm ? You push on the asteriod as much as you pull him. Too bad. bootstraping not a great concept in space me dynamics.
- Captain ! It works ! The aster moves towards us ! We saved mankind !
- Good. Now fire the rockets to bring him away.
- Captain when we fire the rockets it seems to push him away and send it back to earth
- Damn. You mean just like when we use rockets on earth to lift off ? That's a big surprise. Nobody ever though about that back there ? Are they really that stupid ? WTF saving them ? Lets leave them to their fate.
- Captain. What if we land on the other side and fire keep pushing from there ?
- Really ? Allo Houston ?
If you change its orbit, the meteor may be set on a collision course in a later go-around. What you want to do is change its orbit so all future approaches are farther from impacting earth, not just this time. Another-words, pay attention to what you are doing. Do not just do something short term.
wake up and hold your nose
the EM drive has no emissions:
http://en.wikipedia.org/wiki/EmDrive
Some drink at the fountain of knowledge. Others just gargle.
. (and anyone who works at a "museum for science/nature/mathematics") on a rocket and send them out to meet it.
Even if it doesn't work at least we will all at last know paradise, if only for a few brief moments.
That comment is so incredibly stupid that I wonder if it may have been typed by Dr Phil himself.
Using gravity to slowly nudge an asteroid from its trajectory is impractical and a foolish suggestion. Why?
All asteroids large enough to make this work are known and known not to collide with earth. All asteroids that are a threat to earth are small, unknown and liable to be discovered only a relatively short time - certainly not decades - before impacting earth. There is also good reason to expect those to be more common than the claim that they only hit earth "once a century". A typical dangerous asteroid to be discovered will measure between 15m and 100m. That's a simple matter of the chance to detect such asteroids being very small, while the numbers in which they occur are much larger than anything in the several 100m or km class.
We also happen to have just right stuff to do something about the typical asteroids - rockets capable to carry a few tons of stuff beyond earth orbit, anywhere within the solar system. Crash a compact impactor (lead, steel, depleted uranium ... whatever) into the asteroid at your typical speed of 10km/s or more (depending on the exact trajectory and propulsion used) and the kinetic energy released will be sufficient to break it up into small enough pieces. Each ton of material impacting at this speed has the energy of four Tallboy bombs. Those had enough energy to make craters 24m deep and 30m wide on earth.
This works because the large energy is carried by a small mass with little momentum of itself, which means that the energy will be released in all directions, just like a conventional bomb would. Such a collision creates debris small enough to burn up harmlessly in the atmosphere (albeit in spectacular fashion).
"Knowing where the pieces land" seems like a red herring.
If we detect an asteroid a long way out on a collision course with Earth, then altering its velocity by just a bit will push it off of course and it'll miss us. If you set off an explosion near an asteroid, it will indeed likely fragment, but the only way we're still getting hit is if a large chunk somehow gets *no* delta-v from the explosion, and if that chunk is big enough to survive reentry.
OTOH, if we detect a big asteroid close to us, there may not be time for these things, and we need a large impulse quickly.
Either way, "nuke it" seems like the most sensible thing. Yes, this is a drastic thing, but if it's a true doomsday asteroid then it's called for.
Wouldn't it just be better to smack into one side of the asteroid at full speed rather than use a bunch of energy to get to the asteroid, a bunch more to slow down and rendezvous, then use little puffs of energy to try and modify its orbit?
Seems to me that all that reaction mass would be much better served by hitting the rock traveling at 4X,000 MPH.
I am very small, utmostly microscopic.
This "physicist" fucker with the pretentious name is full of shit.
There is no way a spaceship we can actually launch is going to
be large enough to cause gravitational attraction sufficient to
effect the trajectory of an asteroid enough to matter.
The signal-to-noise ratio at Slashdot is approaching 100% uselessness.
Im glad he stopped tweeting retarded shit that didnt even make sense in an attempt to look smart, and is doing actual science. Its hard to have respect for someone who claims a cars performance is based only on horsepower, cant understand why we use horsepower to measure engine output, yet uses AUs in his field of work every day, which are also relativistic non metric units of measurement.
In the course of about seven paragraphs, he manages to take a shot at America twice (good at blowing things up and not dealing with the fallout, if American politicians find out about an extinction level asteroid hitting in 100 years time they'll just kick the can down the road).
I'm not saying that those two observations are false in more general terms, but what evidence does he have that we act that way when dealing with real civilization threats or difficult engineering challenges? He's talking about the one country that has actually landed people on the moon and brought them back - we may have (sadly in my view) changed priorities since then, but we've shown we can do it if we want/need to. And we've generally picked the right side on civilization threats (against fascism, totalitarianism, etc.) - not a perfect record, of course, but compared to the other great powers of the past few centuries, certainly on the better side of the curve (which of the following have we been significantly worse than in the past two hundred years - British Empire, Soviet Union, Germany, Imperial Japan, China?).
The more likely scenario is having to deal with 15 different but legitimate theories and methods to perform the deflection (the gravity solution he prefers, changing the albedo, giving it a nudge, etc.) and either some analysis paralysis based off that or panicked politicians picking the wrong one. Even we Ammurkins have seen enough killer asteroid movies to know something should be done. Heck, if SpaceX marketed it right, it could be a self-financing private venture posing as a movie...
We don't have to follow the "fight fire with fire" methodology. If the weakest force in the universe is pulling an asteroid towards the earth, we needn't use the weakest force in the universe to steer it away. The electromagnetic force is 10^36 times more powerful. Superconducting magnets require only the energy to get them started and keep them cool. Most asteroids are more than one part in a undecillion feromagnetic. So make use of it. And if threat happens to be composed of a diamagnetic material (e.g. comet water), use that to repel it away. Using gravity is just daft unless you have no alternative.
There is already a plan to test deflecting an asteroid by impact.
All asteroids large enough to make this work are known and known not to collide with earth.
All presently known asteroids large enough...
Fixed that for you. We find things in space all the time that we weren't aware of before. You are claiming we know of every body that could possibly threaten us when we cannot possibly be certain of that.
Why can't we go the dinosaur way? What's wrong with that? When it's time it's time. It's extinction! Why bother extending our pathetic time slice on earth? I'd sort of feel good knowing that everyone is going to die the same day as me.
The idea of using gravity (the proper name is Gravity Tractor) to deflect incoming rocks has been around for some years now - and it wasn't Neil's idea.
This might work too if you remember to have them closely orbiting together...
Everything I write is lies, read between the lines.
Let the meteor come!
Remember, best block, no be there.
If Sam Kinison were alive today, he'd apply his philosophy on world hunger and say:
You want to help end extinction-level meteors? Stop sending up shit to blow them up. Don't send them another one, send up huge orbit-altering rockets. Send the UN a guy that says, "You know, we've been coming up with a plan to blow up meteors for about 35 years now and we were blowing stuff up, and we realized there wouldn't BE extinction-level meteors if you people would live where the METEORS AREN'T! YOU LIVE INSIDE AN ASTEROID BELT!! UNDERSTAND THAT? YOU LIVE IN A FUCKING ASTEROID BELT!! Stop wasting rockets by launching them at each other. You too, North Korea... don't give me that look. We're going to do this together in one shot.
The most-effective solution is don't be where the meteor is going to be. This worked well for me the other week. Giant meteor fell in Siberia and I wasn't there.
No, I'm not religious at all, don't believe in any gods, but if a big ass asteroid was coming to hit earth, it is obviously God's fault.
After all, this is all according to God's plan, and if he wants to destroy the earth, who are we to complain?
Seriously, though, if a big ass Asteroid is going to hit earth, it's going to hit earth, no shit you will think of will change that. Start worrying about problems that affect us, not shit that might, maybe, in a small chance in hell, happen.
Be seeing you...
If we worry about a 2 km dia asteroid (rough sphere) it weighs 15 BILLION TONS.
Putting enough energy on over a year or two to pull the asteroid say 10,000 miles is going to be one hell of an amount of energy every second of the year. We don't have that sort of energy source we can deploy that I'm aware of.
I mean hearing him talking about racism and such on one epsiode of Nova Science now I made the mistake of actually looking up his background for all the racism he had to overcome. Let's see, he's the son of 2 college graduates who helped get him noticed with his interest in astronomy.(Since that's the sort of thing where parents can make a big difference.) Because of this he went to Bronx Science and when he went to college he got heavily recruited specifically because of his background, even attracting the interest of Carl Sagan when he was picking his undergrad school. Of course getting all this extra attention probably gave him a huge leg up with college profs actually giving a shit about his education and eventually lead to him going on to a PhD program. As far as I can tell his main experience with racism is sometimes he has trouble hailing a cab.(Yeah, this'll get modded down.)
.... I'm confident that we have little to worry about. Asteroids will tend to avoid our planet out of sheer embarrassment.
I don't care if it's 90,000 hectares. That lake was not my doing.
Why don't we just tell the approaching asteroids that we want a committed relationship, they will veer off course very fast.
If the asteroid is a pile of rubble, then it would seem to be a collection of objects at similar but different distances. This would seem to induce a different gravitational pull on the parts of the asteriod. Could this pull it apart? It would seem likely over the months or years of time spent pulling on the rubble that it would separate into multiple objects resulting in a slower version of the problem from pushing the asteroid. I can imagine that spinning asteroids would require either gravitational pulling or explosions. I think we need a variety of tricks to cope with asteroids and we need to study these objects before deciding the appropriate plan. If we are too slow in discovering a threat, then explosions might be the only choice. We are currently not prepared with any actual equipment to repel any asteroids. We should get busy and start working on smaller objects to work on the technology. Maybe clearing out the debris around Earth would be a good place to start.
Ray Seyfarth, ray.seyfarth@gmail.com, http://rayseyfarth.blogspot.com
for being noncontributing zeroes.
if the observations and calculations were a teensy bit off, and altering the asteroid's trajectory changed it from a very near miss...to a hit?
Huge asteroid is found which will wipe out humans in two years. Scientists and engineers come up with a brilliant and very expensive plan to save humanity. US politicians argue about whether to fund it by tax cuts or tax hikes right up until impact.
If Slashdot were chemistry it would look like this:Cadaverine
gravitational force between a manmade spaceship and an asteroid won't be large enough to make that much of a difference, depending upon the SPEED of the incoming asteroid and the time it takes for us to build a ship, train a crew, and launch it into space. blowing it up could have dire consequences if the asteroid gets close enough to the earth or the moon. but if we can stop it by the time it reaches the asteroid belt, we might be ok.
the last thing we need is some tricky pool shot where you think you're going to hit the right stones but we end up tugging the earth into the corner pocket, game over.
Remember kids, if you're not paying for the service, YOU ARE THE PRODUCT THAT IS BEING SOLD.
Photons have momentum, and momentum is conserved. If you had a coherent enough laser, you just beam the thing when it's still far enough out and the momentum transferred from the photons to the asteroid will change its velocity.
Change it enough, and it'll miss Earth.
I say we do it old school and throw clumps of poo at it.
He's a 'Scientist'.
People like Tyson make my head hurt.... The likelihood of us having enough time to use his method is probably somewhere near 0.. deflection.. certainly as opposed to ablation... but... Seriously? His idea would likely take YEARS to move the path a significant amount unless the object we're trying to mvoe is fairly massive (and the ship we're using is too) and it's actually a -solid- object.... What a Maroon.. anyone actually pay attention to this guy?
Why not send up a swarm of micro ships, each of which attach to a smaller asteroid, and then use their collective mass to affect the meteor's path?
Find it early enough and a gnat's fart will change the angle enough to make it miss the earth. The larger the body - the further we can detectit - the more time to change the angle to miss the earth.
Well, I think a more saner way would be to fire some astronauts up close enough and feed them a lot of beans. We can fund a fart cannon to connect up to their hineys. As an added benefit, we can substitute it for a rail gun here on Earth.
Iranian General: What the hell happened (fire, destruction, troops fleeing in terror)?
Iranian Colonel: Sir, they have resorted to Weapons of Mass Ejection?
Iranian General: You don't mean...they wouldn't...that's below the belt.
Iranian Colonel: That's exactly where we think they fired from, Sir.
I'm surprised, (particularly because the discussion has broken down into push vs. destroy) that nobody has mentioned the Orion Project: http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)
This seems like an elegant solution to the problem, with the added bonus of keeping both camps happy.,
It might be possible to perturb an asteroid's trajectory with a pulse laser. When you hit various materials with very short, intense pulses of light at a wavelength that the target material tends to absorb, it causes such rapid localized heating that it either vaporizes a little bit of material, turning it into very hot gas, (a tiny little rocket,) or it causes a tiny, rapidly expanding piece of material to spall off the surface, (a higher-mass, lower velocity rocket.) Repeat a few thousand times per second and you will basically turn the asteroid into a crappy rocket, using the asteroid's matter as the working mass. The biggest problem I can see with this is that the mass ejected from the asteroid will have a tendency to hit the laser. It might be possible to avoid this simply by aiming the laser slightly off-normal.
... then there would be no way to stop these asteroids. And nobody would even KNOW about them. Because blacks' IQ is too low for them to ever discover and understand ANYTHING about space.
Does that bother you? It should, if there are blacks in your country. Why are they there? Why don't they want to live around their own people, in their own country?
Lead weights? A mini-neutron star?
Even though this works in theory, the asteroid is going to be many orders of magnitude more massive than the rocket in order to cause an extinction event, so this idea is basically like trying to get a flea to pull an elephant by tugging at its tail.
I would imaging that asteroids would make *one* legitimate use for nuclear weapons.
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Before we can really take any meaningful steps toward defending ourselves, we need to get all of the "screw science - let them hit us and kill us all in a bath of fire, so baby jesus can come take us to heaven after the apocalypse!" nutjobs that make up such a huge chunk of our political representatives and their constituents. The first step to finding a way to defend yourself against something is getting rid of the people who want that thing to actually happen.
Just like it did when it saved the planet from global warming.
Discovery Channel already covered this option, or maybe one of the BBC documentaries. And instead of saying stupid things like "feel each other" they spoke about the "long term gravitational effect, however miniscule it would be" - that's what would slowly nudge the asteroid from its existing path and hopefully not into us.
The massive limitation (no pun intended) is that the asteroid in question needs to be detected when it's really really really far away, to give enough time to
a) launch a spaceship designed for this,
b) have it reach the asteroid and then
c) still have enough time/distance for the gravitational effect of the ship to affect the asteroid significantly enough to have it adequately deviate from its path.
While it's the most realistic option from the perspective of current space technology, it's only likely to be useful for asteroids which we already know are likely to hit many many years from now. It would have been more useful to give some sort of indication of time/distance required to actually have it work, relative to the mass and velocity of likely asteroids.
Am I the only one who thought of Project Valkyrie (not the World War II project, the interstellar one) as being a comparatively cheap and easy solution for deflecting or destroying meteors headed for Earth with little advance time?
With only a few modifications (most notably, removing the passenger compartment), a rocket-propelled antimatter delivery system with sufficient antimatter (say, 10 Kg, magnetically isolated) dragging a tungsten shield (20cm thick, say a 20ft diameter disk) a fair distance away (50 meters) would produce upon impact a matter-annihilating explosion of gamma radiation with a yield of approximately 400 megatons (depending on the annihilation percentage), with most of that force being diverted away from the Earth (the tungsten shield absorbing what heads for Earth due to tactical trajectory placement (alignment before impact with the shield being directly between Earth and the meteor creating an umbra).
Another side effect: that much ionizing gamma radiation would undoubtedly weaken the meteor's base components on a molecular scale, making the object much more susceptible to break-up and frictional heat destruction if any of it hit the atmosphere.
Having that much antimatter on hand may be an issue, since, according to the last news article I read about it, 10Kg would be about half of the antimatter currently available on Earth, but the parts already exist, and casting a tungsten disk that size is only a matter of cost, not time. The Newtonian backlash on the tungsten disk would propel it back towards the Earth, but I would rather have a 20ft diameter disk coming at the Earth instead of a house-sized chunk of iron and nickel, wouldn't you?
I don't really see a downside to the plan except lead time.
Any comments would be appreciated.
How about a rocket with a wide flat nose of some sort that can push against the rock and move its orbit so it heads to the sun, and so completely destroys it.
Put in a sail and plunder the universe! Seriously, use a sail to steering it?
Red een boom, Eet een bever!
An extinction level event via asteroid might interupt the extinction level event currently unfolding through man made processes.
Could we hope for a positive outcome as a negative plus a negative (or X) are equall to a positive, thereby cancelling each other out.
Or would it introduce a race condition between alternate realities where the outcome would be influenced by locking and freezing events?
Direct a strong enough laser at the inbound meteor/asteroid and as the incident energy warms the material increasing the rate of sublimation from the surface, the remaining body will be propelled in the opposite direction to the ejected material. Thus "paint" one side of the asteroid and you can expect to alter its path. Other bonuses include it won't really matter if the target is spinning, and the beam will reach the target at the speed of light, so you can keep the laser platform near earth and start altering the course of the inbound object almost as soon as you detect it is on a collision course with earth. With a small constellation of these orbiting laser platforms you can probably always have a firing solution.
http://www.facebook.com/neil.degrasse.tyson.snl.host
Neil, I realize there's a need to dumb things down sometimes, but you're going to provoke suggestions that we criticize the asteroid's weight so that it'll run away crying.
Here's a more useful idea: Use asteroids to improve our situation on Earth. Deflect otherwise-colliding asteroids to pass by us in front of our orbit, not behind us. Let gravitational pull add to our speed around the sun. Let it add to our rotational speed. We need a higher orbit around the sun and less baking when we're facing the sun. I realize the relative masses assure that it won't noticeably help. But it would help more than deluding folks who don't know any better than to believe that asteroids have emotions.
http://www.amazon.com/dp/B00BMU2W9O
even discloses how to build a better replacement for rockets
As long as Bruce Willis is alive there's no need for a deflection-plan. He blew it up once, he'll do it again.
I still can't figure out who he survived the first time though...
We know all km-sized asteroids including their trajectories for centuries...
Really? NASA disagrees with you and I tend to take their word for it over yours. We've discovered hundreds of kilometer sized near Earth asteroids in just the last decade.