More on Asteroid Defense

In a very good piece on the risk from asteroids the Washington Post quotes me going all crunchy-granola:

Tabarrok says his hope is that private efforts in space will one day soon focus on mining asteroids for valuable resources. If you have miners and private developers working with asteroids in space, that could inadvertently make it easier to defend the planet against an asteroid collision.

And of course, there is the option that people on Earth could somehow get the motivation to work together, and asteroid defense might ultimately be a reason for unifying the world, says Tabarrok.

“The idea that the whole planet is potentially under threat from an asteroid does make us think that the world is our home, and we’re all in this together – Spaceship Earth, to get a little crunchy granola. And that makes us think a little more about our fellow travelers, our fellow world residents, that we’re all in this together.”

I may have to turn in my hard-headed economist card.


Alex: Do exercise care with "fellow travelers", that locution still bears echoes, however distant.

As a part-time science satirist and amateur anthropologist, I don't much think the asteroids' "common threat to humanity" rationale will distract us from our internecine purposes. The high-res digital imagery of Earth floating through black space hasn't registered yet, that is, as we close in on the 50th anniversary of the "Earth-rise" photo taken by the Apollo astronauts.

"That's 'cause, like, it was all faked, ya know??? .... didn't you see the documentry? I think it was from Michael Moore..."



The most important advancement in economics is risk sharing, or what we ordinarily call "finance". Shiller emphasizes this point by stating that we'd be better off, and much richer, if all risks were shared; indeed, if all risks were shared, the per capita cost would be nominal. Tabarrok is unknowingly (?) making the same point with the risk of an asteroid collision. It's not crunchy-granola, it's basic economics.

That's absurd. Costs would skyrocket if your risks were shared with everyone else.

Where necessary, risk sharing could be constructed in a way to minimize moral hazard and there is more than enough experience to say that costs can be kept to a reasonable level.

At a basic level, even a minimalist state with police and military is a form of risk-sharing. The whole country contributes to protect citizens from being preyed upon by criminals or foreign invaders even though some people and some regions are evidently at higher risk than others. The modern concept of social insurance expands this idea to health, disability and unemployment risks and natural disasters.

What about the costs to administer these risk sharing mechanisms? And what about the costs of the guan police force you would need to keep the people in their place? The KGB wasn't cheap you know.

I think it's already built-in that costs will skyrocket no matter how you do it because it's a government project. In no time, they'll develop an established bureacracy with its own lobbyists to keep the dollars flowing and their own career scientists who churn out studies showing how serious the threat is. They'll even invent terms like "asteroid threat deniers" to shut off debate with the scientists who claim the risk is overstated.

More relevant is that there is no individual incentive to minimize or take smart risks if the costs are entirely socialized. Moral hazard, writ large.

I think I had a similar reaction. Didn't economists (going back to Adam Smith, at least) invent the notion of social overhead capital? Or gave it a name at least. How siloed has the discipline become that an economist can conclude that pooling resources for the public benefit is somehow antithetical to economic thinking?

Or maybe he was j/k lolz.

Look at the table they have there. Common pool resource problems, like with fisheries or water reservoirs, let's say, are well known, so you might want to think about what kinds of resources you'd really like to see pooled, where they'd fit on that table, and why that would be an improvement over the status quo.

What are the comparative numbers on the existential risk probability from an asteroid strike versus Global Warming?

One of those two results in clear damage that could have a devastating effect on the lives of millions and perhaps billions of people. The other results in a small change to average temperatures. Also the 1st one would be quite cheap to implement, the 2nd insanely expensive.

Strangely the answer for both is the same: since the probability of damage is low and the cost to ward of damage is going down very quickly we should wait to take action on both.

Most importantly :

But wait there's more!

One of the two noted disasters is backed by science which makes predictions which can be verified daily, and which have proven to be correct within an infinitesimal margin of error (celestial mechanics). The only issue is that data gathering for new risks is somewhat costly.

The other scenario has been predicted by models which are very complicated, incomplete, and have yet to make a prediction which wasn't falsified. This isn't a data gather problem, but one of theory.

Again: the solution to both is to wait, but if we had to spend money today it is clear where the rational person would put his/her resources.

What if we substituted for the word


The Phrase

Global Warming.

Would Alex go all crunchy granola and get people to work together on that.

When you can point to the upside of an asteroid hitting the earth in populated areas, the analogy might work.

Maybe the people are all jerks, and now there's new lakefront property?

"What if we substituted... Global Warming"

Good insight. This asteroid "threat" may well be just a deceptive PR lure to get average people worried about supposed catastrophic planetary events... as a spur to massive action on their real issue of AGW (and collectivism).

... "that people on Earth could {should} somehow get the motivation to work together" for asteroid-defense is nonsense.
The R&D and single launch facility required for a viable defense system could be easily funded by lone Bill Gates type sponsor, or by the allegedly large group of wise people who really want asteroid-defense as a top personal priority. Required group action by all the "people on Earth" is an outrageous assertion.

Asteroid defense and global warming work really differently, though.

Suppose everyone but China takes part in asteroid defense. Well, that kinda sucks for the other countries, but we can presumably afford to do asteroid defense without China's money, so it's just a normal free rider problem--we get taxed a little extra to cover what ideally China would have covered in the way of rockets and astronomers and such.

Suppose everyone but China limits CO2 emissions. It's entirely possible that China could push CO2 levels to the point of scrweing up the climate even while everyone else decreased their emissions.

Based on the existing IPCC models, China alone is releasing enough emissions to push us past the 2 degree warming goal:

China wants to peak its emissions by 2030. By then, they could be releasing 3X more CO2 as the US and Europe combined.

This isn't a question of letting some small, poor nation get away with a little pollution while the rest of us pick up the slack. Failure to get China to commit to serious GHG emission reductions swamps every other green initiative combined.

I may have to turn in my hard-headed economist card.

You already have on immigration, which you apparently regard as a categorical imperative. You're probably similarly squishy in other areas where venerable pre-State institutions have been radically deconstructed to accommodate a tiny percentage of the population. I'm betting you don't know how your wife prices school districts either.

Maybe you could just fold in the Econ department with these guys.

I also agree that people tend to free ride just a little to much and assume that asteroids will just be someone else's problem.

"Tabarrok says his hope is that private efforts in space will one day soon focus on mining asteroids for valuable resources."

Has he never heard of Planetary Resources? This focus is already a reality.

The economic model that makes sense here is not for humanity to collectively solve the public goods problem of defending itself from asteroids. It's for Dr. Evil to develop the capacity to deflect an otherwise harmless asteroid toward Earth – and toward a particular country – and charge a lot of money (more than one million dollars probably) to refrain from shifting its trajectory.

If wanting us to "think a little more about our fellow travelers, our fellow world residents, that we’re all in this together" is a sentiment that makes one unqualified to have a hard-headed economist card, then the card was never worth having. Luckily, that is not the case at all.

Just a good investment that would pass a NPV test of any space able state. US Republicans will block it because it's summit spending and Europe will not becasue is would violate "austerity.". Maybe the Chines will step up to the bat.


Having worked at NASA HQ, I can confirm empirically the public goods problem you highlight in the article.

While NASA funds the discovery of potentially hazardous asteroid (PHA) detection at NASA have grown recently, they have not grown to a level commensurate with the level of existential threat to life on Earth. The natural tendency of NASA leadership, both at the Administrator level and within the NASA Science Mission Directorate, is to not want to pay for it.

The number one priority is finding the large number of remaining the PHAs. If you find them, and discover a civilization killer, then you can do something about it. To date, we use ground based telescopes, which are limited because of the atmosphere. To do this, we need to fund some space telescopes that look at the sky in infrared (asteroids give off heat in IR).

Paying for a space telescope that can find most of the missing PHAs will cost on the order of $500M. For some reason, NASA has not been willing to allocate the necessary budget for this purpose. Considering the size of NASA's budget, and the number of spacecraft that NASA funds, this is doable within NASA's budget. But NASA leadership always seem to have more important priorities than addressing this existential threat.

They want somebody else to pay for solving this problem, or to give them extra money to solve it.

For more information on this issue, and the status of NASA's work on this program, read the 2014 Inspector General's report here:

Onwards and upwards,

- Charles

NexGen Space

If it costs NASA $500M, that means a free market competition can find a solution for $100M?

Raul, NASA could put out a tender for a telescope with the purpose of detecting all earth orbit crossing asteroids and regular comets, and then after that large and difficult task was done it be purposed to keeping a vigilent watch for once off hazards from the oort cloud. However, I doubt anyone has the expertise that would give them a large advantage over NASA when it comes to this kind of mostly bespoke engineering. This doesn't mean it's not worth trying, but I really doubt there would be the large cost benefits you suggest. For one thing financing that sucker is going to be a real pain. If it has a 10 year mission then if NASA or whoever is paying for it has any sense then the final payment wouldn't be received until after 10 years operation.


You miss the point. Even if "free market competition" could find a solution for $100M, who pays the $100M?

"Planetary Defense" as a concept has economics that are similar to "National Defense". The probability of death to any single person is so small that it is not worth buying insurance. However, in the aggregate at the civilization level it makes rational sense for somebody to mitigate the existential risk it poses.

However, NASA does not have all the answers. There are many innovative solutions that can come from the private sector and private industry ... the question is "who pays for the solution", and that still comes back to a legitimate role for government to mitigate this risk.

NASA has the authority to establish prizes. It could establish a $100M prize to eliminate the risk from potentially-hazardous asteroids (PHAs). Some space policy experts have suggested a prize approach, however their concept is for discovering individual asteroids using ground telescopes, which is severely limited as a technology for this purpose.

The B612 Foundation has been trying to privately raise several hundred million dollars for a 100% privately-financed solution, but has not been able to raise the necessary funds. They propose to build and launch the in-space infrared telescope we need to discover about 90% of PHAs remaining. They have been trying for at least 5 years, including pitches to many very high net worth individuals. So far, no takers.

The bottom line is as the article that Alex was quoted in from the beginning. Compared to the amount of money that society spends on mitigating similar risks, a $500 million insurance purchase for discovering most of the remaining PHAs is low cost.

The problem is that NASA leaders are in a zero sum game mentality, and if they spend $500M to address this issue, they have $500M less for something else ... like sending a spacecraft to Pluto, or Mars, or to Europa (a moon of Jupiter that some think might contain life.)

- Charles

Charles, a brief consult of Wiki suggests NASA has found most of the PHA objects using the NEOWISE project. Agree/Disagree? Presumably we can find some sort of Congressional testimony to back this up. Free-rider problem at an international scale is not relevant since the US can fund the whole project....the real problem is whether Russia and China trust the US with the ability to manipulate asteroid paths and presumably China and Russia lack the capacity to track these objects themselves.

Woops! Beijing blew up! We certainly had nothing to do with it. Too bad you don't have a tracking system yourself...

A DEFINITE BETA GUY: "Charles, a brief consult of Wiki suggests NASA has found most of the PHA objects using the NEOWISE project. Agree/Disagree?"


The NEOWISE spacecraft is the kind of spacecraft, an infrared in-space telescope, we need to build for discovering more of the unknown potentially-hazardous asteroids (PHAs). While it discovered many NEOs and at least 19 PHAs, it was quite handicapped as an infrared telescope when it started looking for PHAs. It had already run out of its coolant, which keeps the mirror colder and makes it much more sensitive to infrared emissions, which is why it was allowed to look for asteroids after its primary science mission was complete.

The PHAs you see referenced in the NEOWISE wikipedia entry are the 1 km and larger PHAs. But 1 km is an arbitrary number set by politicians. Another smaller number was more recently used (140 meters), but this is still arbitrary. Asteroids as small as 30-50 meters (depending on what it is made of) have the ability to kill large numbers of people here on Earth.

I have not checked the latest data with my friends at NASA, but the wiki entry on this seems about right.
"NEOWISE data estimates that there are 4,700 ± 1,500 potentially hazardous asteroids with a diameter greater than 100 meters.[2] As of 2012, an estimated 20 to 30 percent of these objects have been found.[2] Asteroids larger than 35 meters across can pose a threat to a town or city"

According to this source, they estimate they have only discovered 20-30% of the asteroids over 100 meters in size.

Please note that the exact number of PHAs is unknown, and there is even more uncertainty for the smaller PHAs between 35 and 100 meters. That said, some estimates suggest there are upwards of a million PHAs in this smaller class that are not yet discovered.

These larger number of small PHAs are in the class of the Tunguska meteor from 1908.


- Charles

But NASA leadership always seem to have more important priorities than addressing this existential threat.

SMOD has the most powerful lobbying group in the universe: ignorance.

Again, Orion is the obvious solution, and its 1950s tech.

A battleship-sized Orion could be built for a small fraction of NASA's budget and mothballed against the need. Seems sort of ridiculous not to, honestly.

If the millions of lives are on the line, forget chemical rocketry and tin cans. You want massive ships and huge specific impulse. That means nukes.

A nuclear powered aircraft carrier is now $13 billion and doesn't even fly. So I very much doubt that a battleship sized interplanetary craft could be built for a small fraction of NASA's budget, which is about $18 billion. Then putting aside a one of a kind spacehip and hoping it will work when needed is very risky.

Obviously, if the millions of lives are on the line, forget nuclear explosion rocketry and battleships. You want multiple cannon ball sized impactors and the pathetic thrust of solar sails placing them in highly eliptical orbits ready to act as impactors against likely threats. It's the only way to be sure.

An aircraft carrier is far more complicated and carries planes.

Mass and specific impulse.

BTW, about half that cost of a $14B carrier is the planes and armaments. I'm not proposing an invasion of Mars.

And it's not like you need to put a Westinghouse A4WS in the thing. You could throw together a frame and propulsion system for maybe a billion.

And we have the nukes already. Sunk cost.

Well, it would be one of the more interesting disarmament plans out there...

Unify the world? LOL. It will more likely split the world, because of the free-rider problem.

At a time when the U.S. was struggling to put a single man into orbit aboard a modified military rocket, Taylor and Dyson were developing plans for a manned voyage of exploration through much of the solar system. The original Orion design called for 2000 pulse units, far more than enough to attain Earth escape velocity. "Our motto was 'Mars by 1965, Saturn by 1970'", recalls Dyson (30). Orion would have been more akin to the rocket ships of science fiction than to the cramped capsules of Gagarin and Glenn. One hundred and fifty people could have lived aboard in relative comfort; the useful payload would have been measured in thousands of tons (31). Orion would have been built like a battleship, with no need for the excruciating weight-saving measures adopted by chemically-propelled spacecraft. It is unclear how the vehicle would have landed; it is reasonable to assume that specialized chemically-powered craft would have been used for exploration. Taylor may have anticipated that a conventional Space Shuttle-type vehicle would have been available to transport people to and from orbit. Dyson gives the astounding figure of $100 million per year as the cost of the proposed twelve-year program (32); surely this does not include development costs for the thousands of items from spacesuits to scientific instruments that such a program would require. The Orion program would have most likely "piggybacked" on the military weapons programs and the existing civilian space projects. Still, even if Dyson underestimated the cost by a factor of 20, the revised total would have been only $24 billion, roughly the same as the accepted cost for the Apollo program.

I say solar sails, you say an atomic bomb powered battleships sized spacecraft, clearly we should compromise and use a Medusa variant:

Get out to the asteroid belt and start building habitats in the RAMA style
Mine the metals and good stuff and use the rocky ones for building habitats
Build as many as possible deck them out nicely so folks can live there
Plant launch ready rockets with asteroid steering rocket engines all over the outside.
Also plant telescopes on all habitats to watch farther out.
When an asteroid is detected to have a potential for a collision you have a better chance of sending an unmanned engine to steer it into a more desirable vector.
Screw living on Mars or some other crappy cold ass Moon or in some gravity well. Give me a spinning habitat with a tropical interior and I will live there instead.

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