# Can you describe an effective method to deflect a comet or asteroid headed for Earth?



## matt-browne-sfw (Jan 26, 2008)

Asteroid deflection strategies are methods by which near-Earth objects could be diverted, preventing potentially catastrophic impact events. See also

Asteroid deflection strategies - Wikipedia, the free encyclopedia

In particular
2 Popular strategies
2.1 Nuclear weapons
2.2 Kinetic Impact
2.3 Asteroid gravitational tractor
2.4 Use of focused solar energy
2.5 Other proposals


----------



## Nik (Feb 4, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

Um, divert it just enough to smack into Moon instead ??


----------



## matt-browne-sfw (Feb 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Nik said:


> Um, divert it just enough to smack into Moon instead ??



But how can we really divert it?


----------



## BladeOfFire (Feb 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I think a way to divert it could be created but at the cost of using up opur nukes. If we use a concetrated beam of energy to hit the Asteroid sort of like a tractor beam and fling it out into the vast reaches of space.


----------



## chrispenycate (Feb 17, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

The real answer depends on our technological level and the lead time we've got on the object. If we know twenty years in advance that the orbit of something is going to intercept that of the Earth at the same time the planet is at that point, and we've got interplanetary travel already, then it's not the same problem as if someone predicts a certain comet is going to produce a great show, then it outgasses enough to push it a couple of secondsof arc closer to Jupiter, which swings it off line a whole minute of arc, and suddenly in three months time that comet's got a one in thee chance of hitting the planet heat on, and we've got a couple of shuttles, a few soyuz boosters and whatever the Chinese are using – long march? Well, I suspect it's not even worth worrying about.
A bit more time, and our present technology level, an Orion interception craft  and physical contact, a combination of kinetic and mounting a rocket on it to push it off line. I don't think we could get the ship back, nor do I think either remote control or robot craft are sufficiently flexible, so a manned ship with a sacrificial crew. The further away, the less energy required, so start early. Push it off line as a single lump, if possible (and no-one knows the tensile strength of a comet, so gently does it); if it breaks up, its centre of gravity will follow  the intersection course, and any number of the fragments might hit Earth.
Slightly better warning, a "Star wars" (American military, not a galaxy far, far away) laser aimed at one side of the body (if it's not rotating too fast) boiling off matter from that side and pushing it off line. I would be easier if the thing were already in orbit, and easier still if there were a few dozen of them prepared to shoot down missiles, that could relay each other. Accurate aiming over that sort of distance would be problematic- what, a tenth of a second of arc, and you don't want to miss or hit head on…
Doing the same thing with a solar mirror array is an interesting alternative; what, four square kilometres of mirror (in independent bits, I think, rather than try and move that lot as one) focussed onto a combining mirror which is mobile enough to follow its target with the sort of precision we've just been looking at. And you'd better be darn sure the thing's decommissioned when the crisis is over – the temptation to vaporise Cleveland…
 Kinetic strike  or gravitational attrapment by an asteroid just pushes the problem one step further back, since you'd have to apply as much energy to the asteroid as to the dangerous object. It might be easier if you're already settled in the asteroids, otherwise, it just adds complexity. 
How about a linear accelerator (mass driver) on the moon (installed to lift matter from the moon to Lagrange points, to build space stations) re-aimed to send a continuous stream of rocks (you can make them hydrogen bombs, if you like) at the intruder? Each individual rock would make practically no difference, but the cumulative effect would just slightly slow it down, so the Earth was already past.
Synthetic solar flare? Not for light pressure, but to encourage outgassing.


----------



## Steve Jordan (Apr 9, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I don't think we would need to sacrifice a crew to do the job.  I am a firm believer in robotic tools with human monitoring and some direction/remote control, so I'd propose a module carrying a "swiss army knife" of possible tools, and a second ship to do a flyby with a manned crew to supervise the operation close-up, without landing, then return.

The tools I'd bring would be lasers of various frequencies (to burn part of the object away), fresh boosters, and explosives (to blast part of the object away), all intended to alter its arc (preferably, for the Sun).  Also included would be survey equipment to determine the composition of the object (and help determine which tools or combinations would work best), and possibly some type of netting/scaffolding material to hold the object together during a change in trajectory (if it is deemed likely to fragment upon being disturbed).

The Swiss Army Module (SAM) would arrive first and begin its survey, to be complete upon arrival of the Human Support Module (HSM).  As the HSM arrived, it would begin reversal of trajectory as engineers examined the survey data and made their decision on tools to use.  SAM would be directed and remotely controlled to set up tools and activate them, and HSM would stay on-station to gauge success before going into Earth-return trajectory.

Something else to consider: As opposed to removing part of the object to alter its trajectory, the same could be accomplished by _adding to its mass_ to alter its trajectory.  So maybe a SAM just needs to deposit some appropriately dense waste material to do the job (we're already talking about ejecting trash into the Sun... this would be another way to get it there).


----------



## Urien (Apr 9, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I've always thought a gigantic tennis racket attached to the moon would do the job.


----------



## Grimblade (Apr 9, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

Realistically speaking mankind isn't going to consider anything as advanced or efficient as some of the suggested means listed in this thread, especially considering the current "world leaders". 

Let's face it - if the U.S. had it's way, which for some reason it no doubt would, they'd just nuke it regardless of the adverse effects it would have on our eco-system and morale as a species. Plus, based on their track record they'd probably miss, turn full circle and land a nice big 100 megaton warhead smack-dab in the middle of the Pacific.

Smoooooooth..

So whichever way you look at it the Earth is doomed. But that's what Sci-Fi is all about isn't it?


----------



## Urien (Apr 9, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

This would be a blank post without this sentence.


----------



## chrispenycate (Apr 9, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I'm wondering about solar sail technology - if you had some of the foil available, say a hundred square kilometres you could focus the sun's energy and vaporise one side of a comet generating thrust, with only a few tons of mass to be transported.


----------



## Pyan (Apr 9, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

If there's time...
Drill holes three-quarters of the way through it at right-angles to the direction of travel, fill with water- or CO²-ice. Then bathe it in heat, from a massive laser or solar reflector: the ice boils out of nozzles fitted to the holes, producing a change in the vector of approach, enough to divert it away from a direct hit.


----------



## Grimblade (Apr 9, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

How about using the very same technology to develop a stable energy shield around the planet, thus protecting from any further cosmic caffuffles. How about we all.. WRITE ABOUT IT!? This is turning into a decent muse-thread.


----------



## Nada (Apr 11, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

Actually, in the very question there is an important Dicotomy. A comet or an Asteroid?
The two cases are greatly different. We (humanity) would know of an asteroidal impact with a relevant margin, as a minimum a decade or so. For example Asteroid Aphophis MAY encounter Earth in 2036 if the encounter of 2029 plays badly. In that case it would be 7 years.
For such class of objects, you can try to give a small push so that the accumulated movement over multiple orbits displace the offending object at the "impact" moment. For volatile-rich objects the evaporation of part of the asteroid and the subsequent reaction push suffices. To obtain the evaporation either you use nuclear explosives or sun mirrors/sails or kinetic impactors. For Mass vs. Effectivity ratio a nuke is the most effective method but legal and political issue would probably impede the use of such a tool.

For volatile-poor bodies the gravitational tractor or the mass driver (look at Gregory Benford and David Brin's "HEart of A Comet") would work.
@steve: the removing or adding of MASS has no effect. You need to alter the MOMENTUM of the body. Apply a force in other words.
@pyan: do the calculation: if the material is there, this is exactly what you do; if there is no volatiles, the energy spent to bring water can better be used to build another solution (mass drivers is my favourite)

If instead it is a comet, the situation is dire, MUCH more dire. With the present and near future technological level, and given the present monitoring systems we would be able to see a long period comet when it is more or less at Jupiter orbit. This means 9 to 12 months before impact. All long-duration deviation methods do not work for lack of time.

In a study done in 2005 by the International Space University, named Cassandra, it has been proven that the main issue is not how to deliver the substantial push needed to move the comet, but the humongous amount of Delta-V needed to bring something to impact the comet. Even assuming an encounter with a delta V of several tens of km/s (no matching of velocity) and a very compact "impactor" spacecraft, the fuel needs are astronomical.
See below, there is a link to the report with all the numbers.

If a long period comet is posed to hit the Earth in the next 20-30 years, the only thing humanity could possibly do is try to survive the consequences.

In any case, one has to be very careful about fragmentation methods: if the body breaks up in rather big pieces, it would create a shotgun effect. Instead of a single big impact, there will be multiple slightly smaller impacts, which produce much more damage.

If you are interested, here is the link for the full report:
ISU - CASSANDRA: a strategy to protect our planet from nea-earth objects

In case you find errors in chapter 4 you can complain with the editor here


----------



## Interference (Apr 17, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

DUCK!!!!!


(sorry.  frivolous?  Maybe)


----------



## Nada (Apr 29, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

he he he. You would be surprised, but in discussions on the issue, I listened to people proposing to do that.
By MOVING Earth... 

I'm surprised that I listened...


----------



## Steve Jordan (May 14, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Nada said:


> he he he. You would be surprised, but in discussions on the issue, I listened to people proposing to do that.
> By MOVING Earth...
> 
> I'm surprised that I listened...



Sure, I know that scientific team.  Clark Kent... Hal Jordan... Diana Prince...


----------



## TheEndIsNigh (May 14, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I thought the current thinking was attach a small ion drive motor. These useually have very little power but a small shove in the right direction for long enough has astronomical effects. Thats the problem. If we have years it works however there are comets out there that will 'do for us' and its possible we only get months of warning (if at all). To get something to intercept it may take longer than the time we have.

However, look on the bright side. Given the little time we all have left, a few years here or there dosen't make a lot of difference.


----------



## Drachir (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I'm very disappointed.  I thought by now that one of you would have figured out a foolproof way to save the Earth.  I am going to be very angry if an asteroid falls on my head.


----------



## Hilarious Joke (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

At least it would shut up your whinin'.

Just kidding, Drachir.

Kisses!

HJ.


----------



## TheEndIsNigh (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Drachir said:


> I'm very disappointed. I thought by now that one of you would have figured out a foolproof way to save the Earth. I am going to be very angry if an asteroid falls on my head.


 
now look 'ere. 

It's not my fault you chose to encamp your measly humanity on a rock in the most unstable part of the galaxy. 

Had it the sense to occupy one of the more stable and settled regions the threat wouldn't even have needed discussion. 

Just a mere 20 light years away are some of the most desirable locations for establishing a foothold for new biosperes, being completely free of loose lumps of rock flirting about. 

But no, you thought you could get away in some galactic backwater and now you come moaning about global catastrophies and the threat of imminent distruction.

I wouldn't mind but given the universe will end soon anyway, why bother worrying. All you have to do is ensure that you make the most of things in the short time we all have left.


----------



## Hilarious Joke (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

Yeah, don't dwell on the universe's oncoming death, proclaiming the end is nigh. That's just depressing .


----------



## JDP (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I think that by far the easiest solution would be to divert Jupiter into the asteroid's path, thus saving the Earth. It stands to reason: The bigger the shield the better, and Jupiter is pretty big.

Ha, ha , that was a good one, eh?

Seriously though, I think the best solution would be a manned mission to Mars. They would bore holes to the centre of the planet and send down several dozen nukes to loosen up the core. The team would then fire up their previously installed continent-sized nuclear-powered engines which would reverse Mars' rotation. Mars' core, however, would continue rotating as before, turning Mars into a giant geo(areo)logical magnet. This could then be used to draw an iron-heavy asteroid off its collision course with Earth.

There are admittedly a couple of (minor) problems with this scenario but, hey, it's better than moving Jupiter.


----------



## Cayal (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I'd send up Bruce Willis but that's just me.

A comet or asteroid won't be hitting Earth anytime soon. Considering the size of the universe and how small earth is in comparison I think we are good.


----------



## Nada (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Cayal said:


> I'd send up Bruce Willis but that's just me.
> 
> A comet or asteroid won't be hitting Earth anytime soon. Considering the size of the universe and how small earth is in comparison I think we are good.



Mmhh, sorry to disappoint you, but Earth is not SO small and there is a force called 'gravity' that has the bad habit of pulling things in.

Some fodder for thought: have you noticed how empty the orbital neighborhoods of Earth are? Never wondered where is the stuff that WAS there? Guess guess on which planetary mass they accreted/smashed...

And a small example: Tunguska. 1908. another may come anytime soon. Over a big populated area...


----------



## Steve Jordan (May 16, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

I'd probably worry about asteroid hits a lot more, if I wasn't already working a few blocks from the White House in Washington, D.C. (or, as we like to call it around here, _Ground Zero_)...

Pfft.  I'd count myself _lucky_ if an asteroid got me first.


----------



## Drachir (May 18, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



TheEndIsNigh said:


> now look 'ere.
> 
> It's not my fault you chose to encamp your measly humanity on a rock in the most unstable part of the galaxy.
> 
> ...


 
You and Hilarious Joke are nasty.  I'm going back to Saturn.


----------



## Cayal (May 18, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Nada said:


> Mmhh, sorry to disappoint you, but Earth is not SO small and there is a force called 'gravity' that has the bad habit of pulling things in.



Yes Earth is so small. It's not even disputable, it's fact.



> Some fodder for thought: have you noticed how empty the orbital neighborhoods of Earth are? Never wondered where is the stuff that WAS there? Guess guess on which planetary mass they accreted/smashed...


Must explain all the evidence of asteroids hitting Earth...oh wait..



> And a small example: Tunguska. 1908. another may come anytime soon. Over a big populated area...


The likelihood of an Asteroid hitting Earth is remote. Even this new one everyone is worried about, the Aphpos (however it is spelled), at odds of 1 - 40 chance is still good for us. Sure it's not 1 - 1000, but a 2.5% chance of something happening is not favourable. Ever.


----------



## Harpo (May 19, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

Never mind Aphophis, what about the ones we haven't spotted yet because their orbit lies mostly between us and the sun?


----------



## Cayal (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Harpo said:


> Never mind Aphophis, what about the ones we haven't spotted yet because their orbit lies mostly between us and the sun?



Wouldn't the sun then stop it?

The likelihood of any comet/asteroid hitting us is very small.

It's like you trying to hit a specific dust mite in your room with a piece of lint.


----------



## dustinzgirl (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Steve Jordan said:


> Sure, I know that scientific team.  Clark Kent... Hal Jordan... Diana Prince...



Thats more scientific than my idea...which was to get all the beer drinkers together and have them breath/fart on the asteroid....



I didn't have the time to read the whole thread, but I've wondered, and trust me I'm no science buff I just like science fiction, but I'm pretty sure its not as small as you all think, considering we are basically only protected by jupiter and lunar gravity, so would there be a way of modifying or redirecting the magnetic field that jupiter puts out to deflect an asteroid if there was enough ahead of time knowledge?

We've been hit by asteroids A LOT throughout history, so its not really all that small...the chance of it occurring in anyone individual's lifetime might be small, but the chance of it occurring eventually is 100%.

PS: If you go to nasa's site, there's a link somewhere about the probability of being hit by an asteroid...its something like less than a hundreth of a percent for the ones whose orbits WE CAN TRACK...

Its the one's we don't know about that you should be afraid of. Its _possible_ for an asteroid, say the one that took out those giant reptilian cultures a few millennium ago, has a large enough and strong enough orbit that it orbits outside of our solar system, traveling though the milky way just screwing stuff up and eating little planets like ours. We would, with our sad little human knowledge, have no way of tracking such a magnificent creation of the universe as we have no foundation for exploring its existence or lack thereof.


----------



## chrispenycate (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*

Why would the sun stop them? They're in orbit round it just as we are. 
Fortunately there isn't much inside the Earth's orbit which can destabilise them, and put them onto collision courses.
But "not much" isn't zero. The risk of getting hit in any particular century is low; in any period of a hundred thousand years quite high.
And yes, there have been a number of asteroid strikes over the eons; if the Earth's atmosphere didn't tend to erode them we'd look a lot like the surface of the moon. Not many of them (fortunately) were big enough to cause extinction events, but contained considerably more energy than a hydrogen bomb, and would be quite inconvenient if they hit Cleveland. Even assuming it wasn't taken as hostile action and trigger a missile exchange.
So, while the odds are good for any particular decade, someone has to win the lottery.


----------



## Cayal (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



dustinzgirl said:


> We've been hit by asteroids A LOT throughout history, so its not really all that small...the chance of it occurring in anyone individual's lifetime might be small, but the chance of it occurring eventually is 100%.



Earth is 4.5 Billion years old (if you ask anyone outside of religious groups who think it is 6000 years old)

45000000000 years old. A lot of Asteroids in that time still is a very unlikely chance for our time.

In the end, I am not concerned about Asteroids. Bruce Willis is still alive.


----------



## Interference (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Cayal said:


> 45000000000 years old.



(You've either dropped a couple of zeroes there - real billions - or there's one too many - American billions that we all seem to have bought into now, but I still get confused)

Saying 4,500,000,000 to make things simpler for our American cousins, humanity has only shared 2 million of them with the planet.  That's 4,498,000,000 years we know nothing about with any certainty.  After we've gone, the planet will have another 2-3,000,000,000 years to get over our loss and then the sun will burn out.

I say, one day we will effectively establish a defense network that will protect us from space-borne objects and it will be the result of military research that just luckily has a life saving property,a s well.  However, when the day comes to utilise it, politicians and their military advisors will instead spend their shor days discussing the feasibility of reducing the object to a managable size and directing the resulting missile's its trajectory so it strikes their enemy's home territories.  They will discuss whether the "people" could be convinced that this was an act of God or whether atheism is too widespread, now.  And this discussion will happen on both sides of the adversarial divide, we'll probably all end up smited, not because we couldn't deflect the offending space debris, but because some humans have a vested interest in allowing it to hit.

We're a funny old species, aren't we?


----------



## Nada (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Cayal said:


> Earth is 4.5 Billion years old (if you ask anyone outside of religious groups who think it is 6000 years old)
> 
> 45000000000 years old. A lot of Asteroids in that time still is a very unlikely chance for our time.
> 
> In the end, I am not concerned about Asteroids. Bruce Willis is still alive.



Bruce willises aside, the problem of asteroids hit is that of an extremely unlikely even with a HUMONGOUS (>extremely) damage. The combination of the two make them worse than Earthquakes or Tsunamis. And we built systems to reduce the damage from Eartquakes or Tsunami, right?
That's the point. It shouldn't happen, but the cost in money and lives) of unpreparedness is simply TOO MUCH.

"The dinosaurs died because they did not have a space program"


----------



## Nada (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Interference said:


> I say, one day we will effectively establish a defense network that will protect us from space-borne objects and it will be the result of military research that just luckily has a life saving property,a s well.  However, when the day comes to utilise it, politicians and their military advisors will instead spend their shor days discussing the feasibility of reducing the object to a managable size and directing the resulting missile's its trajectory so it strikes their enemy's home territories.  They will discuss whether the "people" could be convinced that this was an act of God or whether atheism is too widespread, now.  And this discussion will happen on both sides of the adversarial divide, we'll probably all end up smited, not because we couldn't deflect the offending space debris, but because some humans have a vested interest in allowing it to hit.
> 
> We're a funny old species, aren't we?



Well, i can see an optimist there . I think you can be more positive: the damage an asteroid impact could create is:
a) huge, and it spills over (sometimes across oceans)
b) with global consequences (nuclear winter hits everyone, disruption of a big economy as well)
c) unpredictable (very difficult to say in advance where the damage will be

No one with even a primitive knowledge of the problem would risk his own life/wellbeing on these premises


----------



## Cayal (May 20, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Interference said:


> (You've either dropped a couple of zeroes there - real billions - or there's one too many - American billions that we all seem to have bought into now, but I still get confused)
> 
> Saying 4,500,000,000 to make things simpler for our American cousins, humanity has only shared 2 million of them with the planet.  That's 4,498,000,000 years we know nothing about with any certainty.  After we've gone, the planet will have another 2-3,000,000,000 years to get over our loss and then the sun will burn out.



Putting so many zeros on in a row it was discombobulating (what a great word). 4.5 billion years old is what I should have said, but you get the drift.



> I say, one day we will effectively establish a defense network that will protect us from space-borne objects and it will be the result of military research that just luckily has a life saving property,a s well.  However, when the day comes to utilise it, politicians and their military advisors will instead spend their shor days discussing the feasibility of reducing the object to a managable size and directing the resulting missile's its trajectory so it strikes their enemy's home territories.  They will discuss whether the "people" could be convinced that this was an act of God or whether atheism is too widespread, now.  And this discussion will happen on both sides of the adversarial divide, we'll probably all end up smited, not because we couldn't deflect the offending space debris, but because some humans have a vested interest in allowing it to hit.
> 
> We're a funny old species, aren't we?




I don't think we shouldn't ignore the possibility of an Asteroid hitting Earth, despite the highly unlikely event, and researching a system to protect Earth from such things is a good idea (even if we clone 50 Bruce Willis's).

I am just saying I, myself, am not concerned.


----------



## Interference (May 21, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Nada said:


> No one with even a primitive knowledge of the problem would risk his own life/wellbeing on these premises



Ah, but beware of misunderestimating greed and self-interest.   Technology that can destroy an asteroid can ultimately be used to control, fragment and direct it.  After all, the date for this hypothetical collision hasn't yet been set.


----------



## TheEndIsNigh (May 21, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



Interference said:


> Ah, but beware of misunderestimating greed and self-interest.  Technology that can destroy an asteroid can ultimately be used to control, fragment and direct it. After all, the date for this hypothetical collision hasn't yet been set.


 
I think you'll find its some time tomorrow!


----------



## Interference (May 22, 2008)

*Re: Can you describe an effective method to deflect a comet or asteroid headed for Ea*



TheEndIsNigh said:


> I think you'll find its some time tomorrow!



Brill!  No exams!!!


----------

