Russian Meteor Releases "100s of Kilotons" of Energy

As my colleague Jesse Walker blogged earlier today, a meteor exploded over the Ural region of Russia causing some damage and a lot of alarm. Nature.com is reporting that the meteor most likely massed about 40 tons 7,700 tons*, making it the biggest object recorded to hit the Earth since the Tunguska strike in Siberia back in 1908. Nature.com further reports:

A meteor that exploded over Russia this morning was the largest recorded object to strike the Earth in more than a century, scientists say. Infrasound data collected by a network designed to watch for nuclear weapons testing suggests that today's blast released hundreds of kilotonnes of energy. That would make it far more powerful than the nuclear weapon tested by North Korea just days ago and the largest rock crashing on the planet since a meteor broke up over Siberia's Tunguska river in 1908.

In about three hours, a much bigger near earth object, asteroid 2012 DA14 will fly past the earth at about 17,000 miles away. This asteroid is nearly 150 feet across and its estimated mass is about 130,000 metric tons. If it were to hit the earth it would release the energy equivalent of 2.3 megatons of TNT, or nearly 150 times the explosive power of the atomic bomb dropped on Hiroshima.

In my 2005 column, "Earth Killers from Outer Space," I asked if a planetary defense agency might be a government program that you can support? I also noted:

Defending against NEOs is a classic example of a public goods problem. A public good is one, such as national defense, with low costs for an extra individual to enjoy, and high costs to exclude anyone from enjoying. This means that it's unlikely that any particular individual (namely you or me) would pay out of his own pocket to see that the good is provided.

In such situations, we turn not to markets, which excel at providing private goods, but to mechanisms of collective action, generally the government. Naturally, any new Planetary Defense Agency will suffer all the problems that afflict government bureaucracies, especially the innate drive to seek more money and power by exaggerating risks. But given the devastating consequences of an Earth Killer strike, it makes sense to take some strong collective action to protect ourselves and future generations against this risk.

Well, what do you think?

*updated over at Nature.com - Hat tip Eric Hanneken.

Comments

[Death Rock and Skull]

The Biela comet entering earth's atmosphere may have caused simultaneous fires across the upper midwest including the Chicago fire and Peshtigo. True story.

[Paul.]

The Mrs. Oleary's cow is a much more interesting story.

[Suki]

That one was just a cover story for drunk Irish guy Daniel Sullivan.

[Episiarch]

What are you going to do to stop a killer asteroid? Since no one seems to be able to answer that question, isn't your question kind of moot, Ron? You can't shoot missiles at them. Bruce Willis is too old to stop one at this point, and Ben Affleck is too busy directing. What are you going to do?

[A Serious Man]

What's Robert Duvall up to these days? Then there's also Clint Eastwood, Tommy Lee Jones, Donald Sutherland, and James Garner, who are more than up to the task.

[Episiarch]

I'm actually being semi-serious (gasp!) here. How do you stop one? Other than esoteric ideas like attaching solar sails or firing a laser at them to create an energy jet on their side to divert them as they approach, how do you do anything?

[hamilton]

But then you could just re-pose Bailey's question to: do you believe in government-funded research to figure out a reliable methd. Because the likelihood of a private company doing this (in anticipation of the gazillion dollars it could charge when it was needed) is nil. Because if they did, the governments of the world would promptly seize the technology.

[fried wylie]

"Nice asteroid diverting laser you got there, be a shame if something were to happen to you and it walked off..."

[Rasilio]

Actually private companies will develop that technology and they will do so within the next 40 years.

However they won't be doing it to divert an earth collider, they will do it becuase they want to drag that asteroid to either Lunar Orbit or to one of the earth Moon Lagrange points, and then mine that sucker for the metals inside of it

[Suki]

Wasn't that a Newt campaign plank?

[T o n y]

Just heard on NPR that a private nonprofit (with NASA helping out) is raising money to send a satellite on a private spacecraft to be put in orbit around the sun, which will be able to chart 10 times the number of asteroids per month as we have in the past 30 years combined.

If you can detect a collision far enough in advance, you only have to alter the asteroid's speed by millimeters per second to make it miss.

[A Serious Man]

You don't, it's a frickin asteroid.

I cannot change the laws of physics captain!

[Tim]

If you can get decades of warning time, which is posiible, even a mountain can be diverted by a relatively small force. Leverage, This is why we need to catalogue these objects and project their orbits.

[Episiarch]

This is the best answer so far. Because there is very little we can actually do. But even this answer requires sending some kind of ship/probe out for diversion (unless we use the laser solution), which has its own host of problems.

[Tman]

Epi, we've already done it to a giant Comet back in 2004.

NASA's Deep Impact mission changed the trajectory of the comet ever so slightly, but enough to have altered its course so that over time the change in orbit is in the order of millions of miles.

[Episiarch]

I agree, but we have to know about it first.

[some guy]

Given enough time (many years) we could essentially land a "space tugboat" on the asteroid with solid rocket fuel and slowly alter the coarse to miss earth. We have the technology to do this now.

Given less time (many months) we could try to alter its course or break it up using a series of nukes. A bunch of small rocks are less threatening that one big rock. Again, we have the technology to do this now.

Given only a few days we could only evacuate the coasts and tell everyone to hold on to their butts.

[Metazoan]

But how much energy is needed to alter the trajectory of such a massive object?

[Tman]

Not that much actually, because if you find it soon enough you only need to move it a tiny bit. The impactor that hit Comet Tempel 1 was about the size of a closet, but that little change affected the orbit enough to move it, and over the years the tiny bit becomes significant enough to have moved it millions of miles off its original course.

http://www.nasa.gov/mission_pages/deepimpact/main/

[fried wylie]

with solid rocket fuel

In-situ resources. Send up a solar or nuclear powered, self-feeding, mass driver and start chucking hunks towards the sun (send that earth killer mars' way, no one will notice the difference).

[some guy]

That's an interesting idea. It's more complicated than a rocket engine, though. I was going with tech that has already been demonstrated.

We could also target the moon. Put on a nice show for everyone.

[fried wylie]

It's more complicated than a rocket engine

The trade-off for not having to carry fuel/reactionmass to the object.

[tarran]

A nuclear explosion could be used to create a large impulse. Of course, the asteroid could break apart which could easily make the problem worse.

[R C Dean]

Nah. Small bits are much easier on the planet than big chunks.

[Episiarch]

No, both are terrible. Big chunks make for big impacts, but tons of slightly smaller chunks just spread it around.

[Paul.]

If they're small enough, they burn up in the atmosphere. Sort of like your jokes.

[some guy]

Smaller bits are worse locally because you have a better chance of a direct hit, but better globally because less crap gets thrown up into the air and the tsunamis are smaller. Also, smaller mass asteroids lose more mass in the atmosphere than larger mass ones.

For example: A 1-Mton asteroid would be a major impact event. 1 million 1-ton asteroids might not do any damage because few if any of them would make it to Earth.

[Stormy Dragon]

The big chunk results in more immediate damage, but the small bits getting spread through the atmosphere can be just as deadly long term due to nuclear winter effects.

[some guy]

I think it's the other way around. Lots of small bits spread out will kick up less debris than a single large impactor.

[Stormy Dragon]

The small bits don't need to kick up debris. They ARE the debris.

Let me put it this way: when Mount Pinatubo errupted in 1991, it eject 30 billion tons into the atmosphere, and this caused global temperatures to drop by 0.5 degrees Celsius for two years.

By comparison, the asteroid 1036 Ganymed (which crosses earth's orbit roughly once every two years) weighs 36,376 billion tons. Even if it was busted into small pieces and burned up on entry, having that much dust floating around would wipe out humanity anyways by blotting out the sun and freezing us to death.

[Aresen]

Plus the fact that all of the KE gets transferred to the atmosphere in the form of heat: IOW, no crater, but the whole Earth fries.

This is what would have actually happened in the Deep Impact scenario where they blew the big chunk into trillions of tiny bits. The KE doesn't go away just because it is spread out.

[Stormy Dragon]

c.f. Endor Holocaust

[hamilton]

This seems like the 1 horse-sized duck versus 100 duck-size horses conundrum.

[some guy]

That's easy. 100 duck-sized horses wouldn't stand a chance against an adult male human. 1 horse-sized duck could ruin your day.

[Aresen]

One horse sized duck can be killed with a shotgun.

You might get 20 to 50 of the duck sized horses, but the rest would get to you before you had time to act on them individually.

Want to test this? Try swatting one horsefly vs 100 midges - both have about the same mass, but the former is vastly easier to stop.

[Tim]

Are you suggesting that government could make an existing problem worse by tackling it? You are a fooking nut.

[Killazontherun]

Hit right on the trajectory vector, no more objects are going to be using it. A scatter is exactly what you want.

[Episiarch]

No it's not. Comets and many "asteroids" are a conglomeration of pieces of rock. Hitting them with anything is like firing a bullet into a ball of gravel. It'll pass right through and just make the spread a little wider.

This is a complex, complex problem, and we had better hope we never, ever need to solve it, at least not until we have better technology.

[Killazontherun]

Of course it would. You are reversing the concentration of force from the tail to the head. Any change, even a fraction of 1 percent in its trajectory far enough distance away, say a few years out, means it's going to go into a different orbit.

[Killazontherun]

concentration of force from the tail to the head. head to the tail

[hamilton]

But don't you increase the total volume of asteroid that burns in the atmosphere that way? I would think that the burn is related to surface area rather than mass and so by effectively dramatically increasing the surface area you stand a better chance of reducing the overall momentum upo impact.

[some guy]

But don't you increase the total volume of asteroid that burns in the atmosphere that way? I would think that the burn is related to surface area rather than mass and so by effectively dramatically increasing the surface area you stand a better chance of reducing the overall momentum upo[n] impact.

An asteroid has a given density, which we can't really change. So we can't alter the volume. All we could do is break them up to give them a bigger surface area for a certain amount of mass/volume. And that's a good thing. More surface area means the atmosphere can do more work as they fall. Smaller chunks have less chance of reaching the surface, which means less chance of creating a tsunami and less debris kicked up on impact (or aerial explosion.)

[Killazontherun]

If knocked off the trajectory, it is not likely to stay in the same solar plane unless it happened to approach from it to start which is rare.

[Killazontherun]

Roughly speaking, there is a degree of variance that spans out conically from the sun. Smaller at the earth, quite large at the Oort Clouds.

[Tman]

Epi,

In all seriousness we have the technology today available to mitigate the threat. That's not the issue. The issue is finding them in enough time to do something about it.

The one that's passing tonight 2012DA14 was only found a year ago, and we wouldn't have had enough time to do anything about it if it was going to hit.

Again, check out the B612 Foundation sentinel mission.

http://b612foundation.org/

[some guy]

Fortunately the one passing today would only do the damage of a really really big nuclear bomb. Hopefully we've already found all the really big, dangerous ones...

[Tman]

We have not found all the big ones. And although 2012DA14 is small, if it hit the ocean near a major port city the resulting tsunami would be ten times worse than the one that hit the South Pacific back a few years ago. The potential damage from these impacts is much much worse if it hits the ocean, which based on odds alone is more likely to happen.

[KPres]

2.3 megatons is actually pretty small on the H-bomb scale.

[$park?]

Depends on the size.

If it's big, land something with a thruster on it.
If it's not big enough to land on, get something with a thruster near enough to give it a push.
If it's smaller than that, pulverize it so the bits burn up in the atmosphere.

[Stormy Dragon]

Burning the bits up in the atmosphere kills us anyways. It just kills us slowly by blotting out the sun until we all freeze.

[R C Dean]

What are you going to do to stop a killer asteroid?

Nothing, if you don't spot them in time.

I suspect we could deal with a smaller one. Now, one that would dig a crater the size of the Gulf of Yucatan, maybe not (yet).

But stopping one that would obliterate a major city or set off a major tsumani, I bet we could manage.

Nuke it. In orbit. You know, just to be sure.

[R C Dean]

150 feet across and its estimated mass is about 130,000 metric tons.

In the scheme of things, that's not that big. C'mon, fifty yards on a side isn't even a big office building. I bet one of city-killer nukes would deflect/disintegrate it.

Caveat: The less you know about something, the easier it looks.

[Killazontherun]

Caveat: Hitting the earth's surface does not necessarily mean that it will be destructive. It could land on DC, after all.

[Paul.]

This. An asteroid impact has the potential to do trillions of dollars of improvements.

[some guy]

Broken cities fallacy.

[Killazontherun]

Not when applied to the destruction of the Imperial City whose yoke of theft is more costly to the rest of us than any aggregate of product coming out of it.

[fried wylie]

It would be spotted in time enough for those scumfucks to evacuate to secret underground bunkers.

You'd know there's a god when the news reports that the impactor hit the bunker.

[some guy]

And it was a special "bunker-buster" impactor. Very rare.

[Gilbert Martin]

This reminds me of all those killer asteroid programs on various cable TV channels.

The scenario is always that the asteriod will make a bullseye hit on some major city like New York or LA.

They never consider that it might hit out in the middle of the Pacific ocean thousands of miles away from any heavily populated land mass.

[Aresen]

For a 100 meter asteroid, an ocean strike would probably be worse than a land strike in terms of total damage, although you might have enough time to get most of the people out of the cities likely to be hit by the tsunami.

If Apophis hits on April 13, 2036, it is supposedly going to be in the Western Pacific.

[Killazontherun]

Caveat: Hollywood adds non-problems needing solutions for dramatic purposes. An H-bomb loaded missile would have solved that problem without Bruce Willis having to land on the surface

[Raven Nation]

Then he could have stayed on the oil rig driving golf balls at the Greenpeace ship. Everybody wins.

[Alan]

I recall seeing that someone has developed a new missile that can burrow into an asteroid and then explode, which should divert the asteroid and/or break it up into parts small enough not to do serious damage when entering the atmosphere.

[Sudden]

As long as Michael Bay does the casting, we're hopelessly doomed (to survive and suffer the consequences when the sweet release of death was so close).

[freeforall232]

I think the government should throw money at it. After all, that destroys just about everything else...

[KWebb]

Send Steve Buscemi with a .30 cal machine gun, plenty of spare barrels, and lots of ammo.

[Proprietist]

You're such a fool. Even in his advanced age, an asteroid should be no problem for Chuck Norris.

[Tim]

Let's ban asteroids over 10 tons.

[SugarFree]

No one needs an asteroid over 10 tons.

[Tim]

May I point out that this one also attacked a school and injured chilrden? How can we not act?

[Rich]

The gods must be crazy!

[johnl]

Exactly. The problem is so simple.

[Caleb Turberville]

I could easily buy the argument that this is a national defense matter and could, or perhaps should, be a government matter. What I remain skeptical of is the explosion is "science" spending as every astrophysicist seeks grant support to study their favorite solution to the problem.

[Tim]

It would siphon funds from global warming research.

[Caleb Turberville]

Or it could explode into a new cabinet-level department. I nominate the re-animated corpse of Werner von Braun to be secretary.

[LTC(ret) John]

Zombie von Braun, Secretary of Planetary Protection!

[Alan]

Agreed that this is an issue of defense spending, though I would add that science spending in general is often helpful to national defense. Considering the relatively small outlay and potentially vast returns of funding basic science, this is one area of government spending that I don't have a great objection to.

[Tman]

http://b612foundation.org/

The Sentinel mission needs to be moved up sooner.

[DJF]

So a private foundation using a private company is going to catalog asteroids .

What has NASA and the rest of the government space agencies been doing for the last 50 years. Seems like a Sentinel type mission should have been high up on the list of priorities.

[Tman]

You would be correct. And it wasn't. The members of B612 are mostly ex-NASA folks who were tired of being ignored.

[fried wylie]

What has NASA and the rest of the government space agencies been doing for the last 50 years.

Funding paperwork.

[h3k86qc35923]

A lot of broken windows...

[Death Rock and Skull]

JOBS!

[Sudden]

Russia's economy will roar

/Krugnuts

[Rich]

Yep, a decent asteroid strike would solve all our economic problems.

[DJF]

Maybe if it hit Washington DC?

[PS]

Krugman would be in his bunk for a looong time.

[Clich? Bandit]

I would arugue the "Earth Killer" problem is within 100 years of being mitigated. We already have the practical technology to affect the orbits of asteroids we have even landed on two. The key factor being identification and trajectory prediction. THEN, add on top of that the private incentive to profit from the minerals on asteroids/meteoroids and you have a perfect market solution to the problem. It is in no one's interest to see an impact and private forces would be able to react much quicker and efficiently than any "collective" action.

tl;dr No, I don't think collective action is required or even desired to mitigate this threat.

[Death Rock and Skull]

Crystal wavers will complain that you are upsetting the universe's vibes or something by mining asteroids. You can't like own space property, man.

[Paul.]

Yeah, now we're going to do environemental damage to asteroids? Where will the cancerous human reach ever stop?

[Tman]

We have the mitigation problem solved today, that isn't the issue. The issue is finding them in enough time to do something about it.

You only need to change the trajectory of one of these things a tiny bit to make it miss the earth. A few inches here or there makes a huge difference in orbit mechanics over time.

That's why the B612 Sentinel mission is so important.

[Clich? Bandit]

see my third sentence.

[Tman]

Ah, agreed. I took your term of "mitigation" meaning "the interception part" and not both the detection and the interception.

[some guy]

I have to admit I'm a little concerned by the thought of anyone moving an asteroid into orbit for mining purposes. It's one of those cases where the potential damages would be several orders of magnitude above what a company could afford to compensate.

[Aresen]

On the one hand, the fact that all of us would be threatened by a Chicxulub-class event probably means that it merits some sort of collective action. (Although I am sure there would be some "God's Will" types who say we shouldn't stop it.)

OTOH, do you really want to trust the Earth's survival to the same people who 'managed' the Katrina situation?

[Zeb]

"do you really want to trust the Earth's survival to the same people who 'managed' the Katrina situation?"

I don't think I have much choice in the matter.

[LTC(ret) John]

Space FEMA?

[Clich? Bandit]

THATS NOT FUNNY

[some guy]

This would be more like the Space Coast Guard.

[db]

CAAAAAAMPS IIIIIIINNN SPAAAAAAAAAACE!

[A Serious Man]

For what's it worth, a large asteroid could be captured and used as a counterweight for a potential space elevator.

[Tim]

How're we going to build a Haveahart trap that big?

[Clich? Bandit]

All jokes aside this does lead to an argument about the dangers of mining/effecting orbits. A failed attempt could send Starship Troopers like projectiles landing on Rio...and after the article on "brazilians" NOBODY wants that.

[Death Rock and Skull]

The space elevator concept is already impossibly bizarre enough.

How you going to use an asteroid as a counterweight unless it is one time use? Is you going to find the energy to lift it back up?

[Zeb]

That's not the kind of counterweight you need. It would need to be placed in geosynchronous orbit to provide the tension needed for the space elevator cable (or whatever it climbs). At least that is my understanding of how proposed space elevators would work.

[Alan]

Yes, although I rather like DRaS's misconception.

[Death Rock and Skull]

Yeah, I was thinking of a normal elevator with a counterweight. I would call the other thing a satellite. I don't remember that being called a counterweight before.

[some guy]

A space elevator is just a satellite that is tethered to the earth. The center of mass of the elevator would have to be beyond geosynchronous orbit for it to remain taut.

It's a daunting endeavor, to be sure, but it has the potential to reduce space travel costs by several orders of magnitude.

[The Late P Brooks]

This is plainly a direct result of global warming.
End fossil fuels, NOW!

[hamilton]

I think you are not well-considering the effct such an asteroid would have on women and disadvantaged minorities.

[Clich? Bandit]

will they be hardest hit?

[Libertarian]

"Asteroid strikes island of Lesbos. Women and minorities hardest hit."

/NYTimes

[Endless Mike]

C'mon, who would be silly enough to actually believe that?

[A Serious Man]

I'm probably late to the party here, but in Soviet Russia meteor showers you!

[Don Mynack]

I say we go ahead and declare America an "asteroid free zone". That way, no asteroids will hit us.

[johnl]

We'll need an enforcement agency to prosecute people who have unpermitted asteroids.

[Sam Grove]

First, let space exploration become profitable, that will solve the problem of extra-planetary presence.

Then, if a threat is found, I'm sure we could get enough money to deal with it by voluntary collection.

Any government with the power and sanction to force us to pay for it will also subjugate us. Notice I said "will", not "may".

[Zeb]

Perhaps you should have said "has already".

[Tman]

Here's an interview with Ed Lu discussing the Sentinel mission.

https://www.youtube.com/watch?v=YGHSr4vVUrk

[Death Rock and Skull]

You really have a hard on for that, don't you?

[Tman]

ROCK HARD baby.

[Lord Humungus]

meh - let the meteors come and go as they please. Open (space) borders!

[Tim]

Doing the jobs Earth rocks won't do.

[Tim]

The only way this story could have been better is if it hit that Carnival Cruise ship.

[Rich]

Or Jerusalem.

[Tman]

Uh, they just released a new video of another meteor found from last night.

Except this one is from JAPAN.

http://www.theregister.co.uk/2.....rth_japan/

[Tim]

Soon we will be up to our global ass in Martians.

[thom]

I don't know why this theoretical government agency would want to track my movements, keep a database of my private information, and scan me with weird machines, but I'm pretty sure they would want to.

[LTC(ret) John]

Space TSA?

[Fatty Bolger]

Plus they could do Muslim outreach in their spare time.

[np]

http://www.youtube.com/watch?v=duEzrOvSb98
Planetary Resources President/Chief Engineer (and former NASA scientist) Chris Lewicki presents his talk entitled, "Asteroid Mining: The Compelling Opportunity and What It Means For Mining On Earth, Today." Presented January 2013 at Cambridge House International's Vancouver Resource Investment Conference.

[np]

Russian meteorite update
In our previous update, we mentioned that many asteroids pass by Earth with little or no warning. We were not exaggerating. Despite considerable progress in asteroid detection, only about one in ten close-approaching asteroids are known about ahead of time. While not every approaching asteroid may be detected, and with little warning not all can be prevented, in this case a little warning would have prevented many injuries, and quelled the panic that followed.

Future asteroid mining industry will provide capability to aid the deflection of potentially hazardous objects near Earth

[db]

Got that in my inbox earlier today.

[Death Rock and Skull]

You really can't bitch if we don't manage to survive an asteroid. If we can't figure it out, that's just our journey.

[Dr. Frankenstein]

Why do meteors hate Russia?

[crashland]

But anthropomorphic changes to the universe are bad, therefore doing anything to alter the natural progression is by definition evil... A large strike might save us from global warming by tossing enough shit into the atmosphere to reduce the earth's "fever." If it also wipes out 1/5 of the population, that's great because people are a plague raping mother gaia.

[Gilbert Martin]

"This asteroid is nearly 150 feet across and its estimated mass is about 130,000 metric tons. If it were to hit the earth it would release the energy equivalent of 2.3 megatons of TNT, or nearly 150 times the explosive power of the atomic bomb dropped on Hiroshima."

But nowhere near as powerfull as the Soviet TSAR bomb detonated in the early 1960's. That one was 50 megatons.

[Aresen]

Blowing a large asteroid or comet into a bunch of tiny pieces that burn up in the atmosphere is NOT a "solution".

What causes the problem with an asteroidal or cometary impactor is not the dimensions of the object; it is the kinetic energy that it carries.

A 5 mile wide asteroid, assuming a specific gravity of 1 and a terminal velocity of 20 kps carries approx 8 x 10^30 joules or a trillion megatons of energy. So, even if you hit it with the entire nuclear arsenal of all the nations on Earth, you are not going to change that number significantly.

That energy has to go somewhere. If it all gets burned up in the atmosphere, you are going to raise the temperature of the atmosphere over 150 ? C, roasting everything on the planet surface.

"Blowing it to bits" is not going to save us.

Of course, the dust left in the atmosphere and the soot kicked up by all the firestorm on the ground is going to add to the problem. There is also a probable total destruction of the ozone layer and severe particulate contamination of both sulphates and nitrates.

[Aresen]

Correction 10^30 ergs. The other numbers are correct.

[Killazontherun]

Tsar Bomba blast was 2.1?10^17. That alone would not be an insignificant blast on the surface of a five mile wide asteroid.

[Aresen]

Not even one part in a million of the KE of said asteroid, assuming the entire energy of the Tsar bomb manifested as KE.

[Killazontherun]

You realize what converting to ergs does to your numbers? A joule is 1?10^7. That measurement of Tsar Bomba is in joules.

[Aresen]

1) Yes. I did the conversion before I calculated the effect of the heat generated as the KE is transferred to the atmosphere. I just forgot to change 10^30 to 10^23 before posting.

2) The Tsar bomb is still insignificant compared to the KE of an asteroidal impactor.

3) Note that I used a low specific gravity (1) for the impactor.

[Killazontherun]

To the point, H-bombs not only level cities but create seismic activity on an object, the earth, that is several magnitudes larger and denser than a five by five mile sized asteroid. Are you saying that such a force that can make the earth tremble, could not knock an asteroid from its trajectory? Actually, I've seen calculations of using all the nuclear arms on the earth as of their capacity in the 80's that conclude the use of which would shift it from its current orbit. So, what is so magical about asteroids, then?

[Aresen]

Actually, I've seen calculations of using all the nuclear arms on the earth as of their capacity in the 80's that conclude the use of which would shift it from its current orbit.

Who did those calculations? Velikovsky?

The energy involved in changing the Earth's orbit (Earth mass ~ 6 x 10^21 tons) is many orders of magnitude beyond the effect of any nuke.

I wasn't talking about "diverting", I was talking about "blowing it to small bits" as in Deep Impact, where all the bits hit the atmosphere.

Diversion could be done by a delta v of 1 cm/sec if applied early enough. (ie More than 30 years) That IS within the capability of a nuke, though a nuke might not be the best way to do it.

[Killazontherun]

I wasn't talking about "diverting", I was talking about "blowing it to small bits" as in Deep Impact, where all the bits hit the atmosphere.

I thought you were responding to Gilbert above when you said So, even if you hit it with the entire nuclear arsenal of all the nations on Earth, you are not going to change that number significantly.

[Gilbert Martin]

My post had nothing do with trying to blow up ateriods with H bombs.

I was merely responding to the comparsion made in the article to the Hiroshima bomb and observing that a 2.3 megatone effect of the 150 foot asteriod was a lot less than the 50 megaton H-Bomb set off by the Soviets.

[Killazontherun]

There was a huge inference in your post that you were going to sign over a million dollar check to kickstart my blow asteroids up with H-bomb project. We all saw it!

[Killazontherun]

Who did those calculations? Velikovsky?

Back in the Nuclear Winter debate, saw it in a conference paper. I should have mentioned that as caveat.

[Killazontherun]

A hydrogen bomb would level LA, correct? If we sent LA flying through space at 17,500 mph and hit it with a bomb then it suddenly become immune? No, there is a conceptual problem to how you are treating kinetic energy here.

[johnl]

I like where you are going with this. Maybe we can send DC instead flying through space.

[Aresen]

"Levelling LA" is not equivalent in terms of KE to "accelerating the mass of LA to 17,500 mph."

An overpressure of 5 lbs/in^2 is sufficient to level a city. It is not sufficient to accelerate it to more than a few miles per hour.

[Killazontherun]

So, if we rebuilt LA on top of a five mile by five mile square of real estate, an asteroid, sent it flying in space, and blew it up with an H-bomb, though the city on the surface (whose overall density is represents quite a bit of tonnage) would be wiped out, the asteroid itself would go unscathed? That is what you are saying? Be aware that seismic activity from nuclear explosions like the one conducted this week in North Korea are felt around the world.

[Aresen]

Mass of a 5 mile cube:

Assume specific gravity of the cube = 3 = 186 lbs/cu ft (typical upper crustal density of Earth; Earth as a whole has a density of approx 5 gm/cc)

(5 x 5,280)^3 = 5 mile cube expressed in cu ft = 1.8 * 10^13 cu ft

= 3.4 x 10 ^ 12 tons ~ 3 x 10 ^ 12 metric tons ~ 3 x 10 ^ 15 kg

Escape velocity = 11 kps (you need to reach escape velocity to hit the asteroid; 17,500 mph or 5 mps or 8 kps is only low Earth orbit)

Each kg accelerated to 11 kps requires 6 x 10^11 joules of energy.

Therefore, the KE of a 5 mile cube of earth crustal material accelerated to a velocity sufficient to intercept the asteroid is of the order of 1.8 * 10^24 joules. (Note that this is less than half the KE of our putative asteroid, which usually have a terminal velocity between 20 and 40 kps.)

[Killazontherun]

Don't let my 17,500 mph figure throw you off, that is slightly faster than what the asteroid that just past clocked. I assume it to be a fairly average speed for an object of its type pass earth orbit.

If an event is 30 years off, I assume mining the asteroid of its vital materials and destructing the remainder would be the way to go instead of nuking it.

Still, the world would all be safer if some nukes were handed off to me so I can test them on some asteroids.

[Aresen]

"Don't let my 17,500 mph figure throw you off, that is slightly faster than what the asteroid that just past clocked

Wrong.

The DISTANCE from Earth at closest approach was 17,100 miles. That has nothing to do with it's velocity.

As it's orbit was close to Earth's, its orbital velocity had to be approximately the same as Earth's, or around 29 kps (18 mps or 65,000 mph). As I don't know the approach angle, I can't say what the relative velocity to Earth was.

[Killazontherun]

I based that on the reported speed in the WSJ: Even there, all anyone can see is a pinpoint of light as the asteroid zooms by at 17,400 miles per hour. As asteroids go, DA14 is small.

http://online.wsj.com/article/.....41820.html

Heard it closely (17,450 mph) repeated in NASA's live webcast.

[AlmightyJB]

Washington just needs to pass a law making it illegal for an astoroid to enter our system. Duh.

[Gilbert Martin]

Yeah.

And while, they're at it, they can make black holes and gamma ray bursts illegal as well.

[Aresen]

Wnat about the asteroids that are already in our system?

There are millions of them.

[Gilbert Martin]

That reminds me, I heard a new "doom" scenario on one of those "Universe" programs last night that I'd never heard before:

The entire Universe will be destroyed by the "big rip".

It seems that dark matter is pulling the Universe apart causing it to expand at an increasing rate and eventually everything in the Universe will be ripped to pieces - about 15 billion years from now.

[Killazontherun]

Don't worry. I have a plan to give the Big Rip syphilis, once weakened, attack it with Super AIDS.

[Rasilio]

Yea but the Universe would be effectively destroyed well before that as the universe expands to the point where stellar formation is no longer possible and the existing stars become gravitationally unbound from their galaxies

[Invisible Finger]

I imagine a remake of "The Gay Divorcee" is in the works. Probably porn.

[Pinky]

This is all very interesting, but it all fails to answer the question, "Why do meteors hate Russia?"