Deep Impact

Tyler Cowen notes some evidence that astronomers have been underestimating the frequency of catastrophic asteroid impact events here on the planet earth. Depending on how you interpret a certain set of deposits, it's possible that super-huge impacts occur once every few thousand years instead of once every 500,000 years or so.

At any rate, it sounds dumb, but I really do think the world's major governments should pony up the money that would be required to better track the paths of asteroids and the like. Right now, we don't really have a good sense of where everything is all the time. Building the necessary monitoring capacity would be pretty cheap if you put it aside other kinds of national defense expenditures, and it would be something all the big players and wannabe players (USA, EU, Japan, Russia, Brazil, India, China, whomever else) could do cooperatively. Whatever the exact frequency, the question of an extremely destructive collision with an object in outer space is very literally a "when not if" sort of thing. Given ample warning, though, people could probably figure out some countermeasures. Keep in mind that beyond the truly catastrophic impact events, there are things like the Tunguska Event that could kill hundreds of thousands -- if not millions -- if they happened in a big city.

Comments

It is my understanding that something like a Tunguska Event, can kill more that just the folks in the area. These impacts kick up a buttload of dust, changing weather patterns all around the world affecting agriculture so that people far away starve.

Posted by cw | November 15, 2006 10:48 AM

I worry about things like asteroid impacts. Surely, there are other concerns more 'immediate,' some may argue. To me, however, nothing can be more immediate than news of an incoming rock of such mass as to cause global devastation. There exist plentiful clues that such has happened in the past, yet (seriously) the number of people actively looking full-time for rogue asteroids could staff a typical McDonald's. And that's mostly in the Northern hemisphere (where most of industrialized civilization resides and thus the technology to look)--one could come right up from 'under' us as well.

I worry because if such were to happen, everything that human beings are is lost; our cultures, experiences, achievements, regrets, relationships-all of it, is gone.

What makes this issue particularly irritating to me is that we've had the technology to begin to look into things like deflection or destruction of killer rocks to preserve our earthbound culture as well as space colonization, but we have not. I continue to hear arguments such as 'we should stop wasting money on space and focus on our earthbound problems.' The fact is, a fraction of 1% of the US GDP is allocated to NASA, and it has been thus for quite awhile. Compare that, for example, with well over 30% of the GDP spent on welfare and similar social programs. I don't know about you, but I'm willing to support that value for programs that look into our ultimate survival. One of my favorite quotes sums it up:

"Alas, at the very time when humanity had reached the pinnacle of its knowledge and power, when it could begin to unravel the mysteries of the universe, it instead got caught up in its own false values, vanities, and petty ambitions. It was then that the big rock came and made everything they had ever been or ever could be moot." --Terraformer

Posted by Terraformer | November 15, 2006 10:49 AM

The possibility of a major asteroid impact, of course, is why the Bush adminstration has called for a preemptive invasion of Mars . . .

Posted by rea | November 15, 2006 11:19 AM

Well, the good news is most (if not all) of the required technologies & systems are comparatively cheap and would have interesting dual uses as well. Asteroids that spend most of their time outside Earth orbit could be monitored using existing telescopes, I think. What's required is a coordinated search effort (amateur and professional astronomers are already doing a good job). Later, something like the "Large Synoptic Survey Telescope" ( http://www.lsst.org/About/Tour/neo.shtml ) would clearly be very useful as it would be able to quickly discover even the faintest asteroids out there. It would be very expensive, but other fields of astronomy would find LSST very useful as well.
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As for space-based solutions, I understand Earth-crossing asteroids from the inner solar system could in many cases only be detected from space. The cost need not be higher than for other unmanned space science satellite missions, however.
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If the detection system is very good, there will be ample time to do something in case we discover an asteroid that will impac t the Earth decades from now. Probably the best countermeasure would be a large robotic spacecraft akin to President Bush's recently cancelled "Jupiter Icy Moons Orbiter". It would use nuclear-electric propulsion to rendezvous with the asteroid and then keep formation with it for a decade or more; the gravitational pull from the probe would slowly "nudge" the asteroid out of harm's way. It seems there is no need for more complicated systems such as e.g. nuclear charges.
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BTW, I am a bit surprised "Shrub" did not choose asteroid defense as NASA's next major space effort ... It would have been quite compatible with this Administration's overall "vision" wrt. WMDs etc..

MARCU$

Posted by Marcus Lindroos | November 15, 2006 11:20 AM

I was kinda with you until the comparison of NASA's budget to welfare and "similar social programs" (whatever the hell those are). Maybe the money should be redirected from something like the useless missile shield?

Posted by Matt Weiner | November 15, 2006 11:21 AM

These impacts kick up a buttload of dust, changing weather patterns all around the world

The whole world would have to switch back to worrying about global cooling again. Which would obviously be a disaster...

BTW - Shouldn't this post be entitled "Armageddon"? That would be a the clearly superior title.

Posted by Al | November 15, 2006 11:37 AM

What of the frequency of mutant lizard-like dinosaur monsters rising out of the sea, coming ashore and destroying major population centers? Hmmmmm?? Huh, huh? I'd say some kind of early warning system is called for here. TRW, Raytheon and Siemens could probably use an earmark, just seed money of course. $400,000,000,000 should eventually do the job.

Posted by steve duncan | November 15, 2006 11:42 AM

I think that this is basically in process. NASA has had a goal of identifying 90% of near-earth objects of size 1 km or larger by 2008, and they currently estimate that they have found about 80% of them. More recently they've extended their search to objects of 140 m size, and are in the final stages of building equipment to pursue this goal. Check out

http://space.newscientist.com/article/dn9403-new-telescope-will-hunt-dangerous-asteroids.html

-PT

Posted by PT | November 15, 2006 11:47 AM

> I worry about things like asteroid impacts.
> Surely, there are other concerns more 'immediate,'
> some may argue. To me, however, nothing can be more
> immediate than news of an incoming rock of such mass
> as to cause global devastation.

While that concerns me too, my immediate worry is a smaller asteroid (large meteor) that comes from the direction of Iran (say), flashes on the radar screens just long enough to get a back-track, and then impacts on or near an East Coast city. The "retaliatory" ICBMs would be flying long before anyone had time to do a radiation survey of the crater.

Cranky

Posted by Cranky Observer | November 15, 2006 11:52 AM

Without addressing the merits of the question, you really shouldn't post on ssubjects like this, ebcause it attracts comments from peopel with names like "terraformer" who will pester us with their favorite quotes from themselves.

Posted by lemuel pitkin | November 15, 2006 12:00 PM

I worry about the bacteria growing and mutating inside poopy diapers wrapped in plastic bags in landfills. One day, a backhoe comes along and rips the protective plastic bag, and the next day millions of half-eaten zombies roam the earth.

Posted by Jeffrey Davis | November 15, 2006 12:14 PM

This tends to be an issue most people find either ridiculous or irrelevant. It's not just that it's too vast and vague a threat to comprehend, or too expensive - no, even if they do get it people seem to resist on the grounds that it's just not something governments do; it's not been done before. When the threat comes we'll figure out something or someone will have already figured out something.

The thing is, organizations like the WHO or CDC would have been unimaginable or laughable just 100-200 years ago because we weren't aware of the threats posed by microscopic organisms. Now we are, and we have agencies to study them and defend us.

The same should apply to space-based threats. Asteroids and other material become meteors with enough frequency that they should receive the same scrutiny and caution as our tiny Earth-bound friends.

Posted by Adam | November 15, 2006 12:35 PM

Jeffrey: And that's just *one* of the possible vectors for Zombie annihilation! We should also be funding Indian Burial Ground Defense, Necronomicon Destruction, etc., etc.
Seriously tho', asteroids aren't where it's at--they have predictable, relatively short (less than a hundred years) orbits, and might even be solid enough to push with a thrust engine or nearby nuke. Comets, on the other hand, can have million year orbits, remain invisible until quite close to the sun, and change direction unexpectedly from all that crap they throw off when they're hotted up. There was a nice spooky piece on the whole subject in the Atlantic (or was it Harpers?) four or five years ago--I'm sure any student with free Lexis could find it.

Posted by max | November 15, 2006 1:07 PM

You have to know where to draw the line. Large, civilization-ending asteroids are easier to detect, so obviously we should make the necessary efforts. It is much more problematic to decide how much we should spend to detect things like the Tunguska object. They are harder to see, and would be more likely to cause no deaths at all than to cause some deaths. True, one could kill millions, but their effect is not global.

So, a Tunguska-like object might impact the Earth on a time-scale on the order of 1/century (give or take an order of magnitude), would probably cause no damage, but would have an expectation value of about 200 deaths considering the percentage of the Earth's surface affected. That means that we should be expecting to lose about 2 people per year to Tunguska-like objects hitting the Earth. What are you willing to give up to save those people? Once you've spent as much as the cost of a kidney dialysis machine, you're probably misusing the money.

http://newton.dm.unipi.it/cgi-bin/neodys/neoibo

Posted by Njorl | November 15, 2006 1:15 PM

Oops, the link above was supposed to be in this post.

http://newton.dm.unipi.it/cgi-bin/neodys/neoibo

it has lots of info on near-Earth objects and the efforts to track them.

Posted by Njorl | November 15, 2006 1:16 PM

Re: While that concerns me too, my immediate worry is a smaller asteroid (large meteor) that comes from the direction of Iran (say), flashes on the radar screens just long enough to get a back-track, and then impacts on or near an East Coast city. The "retaliatory" ICBMs would be flying long before anyone had time to do a radiation survey of the crater.

I'm not sure such a trajectory would be possible. An asteroid that came in at an angle oblique enough to orbit half the planet might just bounce off the atmosphere back into space after putting on a really spectacular display. Besides which astreoids are bound to look very different on radar than missiles (which are much smaller) do. And satellites would be able to tell the difference too

Posted by JonF | November 15, 2006 1:26 PM

Yes, without accurate tracking we might all be dead before we even had a chance to do the mass panic thing.

Posted by John Emerson | November 15, 2006 1:55 PM

"Yes, without accurate tracking we might all be dead before we even had a chance to do the mass panic thing. " - Posted by: John Emerson

Which reminds me -

An astronomer and a construction worker walk into a bar. Barman asks what they do.

"I'm buildin' an observatory on the hill up the road" says the worker.
"Really, I'm going to work there, tracking asteroids that might hit the Earth", answers the astronomer.
"What would you do if you heard an asteroid was gonna hit the Earth?", asks the Barman.
The construction worker answers, "I'd grab the nearest thing movin' and fuck the shit outta it! How 'bout you doc?"
"I think I'd remain perfectly still."

Posted by Njorl | November 15, 2006 4:15 PM

Uh, don't we have about 90% of NEO cataloged? I think we're doing pretty good as these things go. Need more lasers though.

Or mega-particle cannons.

Posted by MNPundit | November 15, 2006 6:45 PM

"...a species that could watch, with mild interest, huge, continent-destroying lumps of ice smash into a planet that was Right Next Door in astronomical terms, and then do nothing about it because that sort of thing only happens in outer space." --Terry Pratchett

Posted by ajay | November 16, 2006 7:14 AM

the error bars on the remaining dangerous NEOs are still fairly large, actually. the cool thing is that a serious project like Pan-STARRS (PT's ref above, or http://pan-starrs.ifa.hawaii.edu) or LSST will not only detect lots of dangerous rocks, but will also make huge inroads in other astronomy fields as well. And it is pretty cheap as far as these things go. Pan-STARRS is only a 40 - 80M dollar project, even for the full 4-shooter system. and in this case, it is the air force putting up the funds, not nasa. actually, nasa almost never funds ground-based telescopes (though they put some money into some of the smaller neo projects, i think). LSST is being funded by NSF, who have a much smaller budget than NASA.

Posted by foo | November 16, 2006 11:36 AM

It turns out that NASA and the Jet Propulsion Lab at Cal Tech are actually working on this.

There's a project to locate all these things - congressional mandate and all. See: http://neo.jpl.nasa.gov/neo/

Here's what they've got so far: http://szyzyg.arm.ac.uk/~spm/

There's also some interesting research on how to deflect them. Most of the scenarios don't look good - it would take a lot of force for a realatively long time to deflect anything big enough to be concerned about, and that's hard to get. It turns out that blowing an asteroid up pretty much wouldn't help because the center of gravity would continue on it's orbital path and the chunks would still be pretty big. So instead of hitting one city you hit many. That doesn't exactly help.

Any way... I'll check with my friends in the field and see if there's anything else worth knowing about this. But don't worry - the brains at Cal Tech and NASA have you covered.

Posted by The Black Monk | November 17, 2006 10:21 AM