>> 0 friar winning the nobel prize, in the three or four months before that the kremlin

was getting notices from sweden, from their embassies and friends that pasternek was short-listed for the prize and he could cause a scandal if he won and the book was banned in the soviet union so a memo was written proposing they publish 10,000 copies and circulate them to no one. so, they would announce, we've published dr. zhivago but we wouldn't distribute it to anyone. that idea was rejected and instead they came up with a plan to vilify pasternak and force him to renounce the prize, which they did. he was the first recipient of a nobel prize to be forced to renounce it since hitler did the same to some germans in the 1930s.

[inaudible conversations] >> a problem we have. i first read the book when it was out. then came to work for the cia, and then i had to read it again once i discovered the significance of the book that i had not -- it would so complicate, nonetheless, it became very popular and the cia currently, historical division, does in fact plan to have more special events related to the book, and if you can -- many of us who have been musicians and if you'll pick the right time

and place you can hear me playing the piano in the bar next door. thank you very much. >> thank you. i appreciate it. [applause] >> every weekend, booktv offers programming focused on nonfiction authors and books. keep watching for more here on c-span2 and watch any of our past programs. >> up next, "after words," with guest host -- this week, william bur rose and his book "the asster rate thread" revealinger in collisions between the earth and asteroids and discusses what can be done to defend against it. this program is an hour.

>> host: i'm talking to womennum burrows about the asteroid threat. i would characterize it how astronomers, scientists, might some day save the world, and how would you characterize your book? >> guest: i think you did it very well. i would, whichize it by saying that my point is that we are -- we don't have to be the hapless, helpless victims of nature. my friends in nasa and elsewhere in the space community, like to say the dinosaurs had had a space program they would still be here we have the wherewithal to save ourselves, and the book, the most important point of the book, it explains that and comes out with a plan, and the plan was not invented by me. it is pretty universally accepted within the community. >> host: so, my impression, at least, you're advocating us

spending quite a lot more on this problem, on plan -- plan net -- planetary defense. >> guest: yes. the cold war is over and peace has broken out. when i say it would cost a lot of money, i say what is it worth? the dinosaurs were blown away. it can happen again. the chances are it's not going to happen very soon, but doomsdays always a possibility. so what i'm saying is protect yourself. that is a very good use of money. >> host: so, what are you advocating that people should do? if you had a few billion dollars or king of the world, what do you think is the right thing to do? >> guest: well, would set up a permanent planetary defense system, and i would -- within the community -- this is acknowledged as having three

parts. part one is you have to have the sensors on the planet, infrared sensors on the planet and off the planet to spot in so-called potential impact that is coming this way, and it looks like it's going to hit. part two is, you have to be able, with 20 or more years notice, you have to be able to send a spacecraft out that will nudge it off course along before it gets here, and given the distance, nudge it off course by just a tiny amount will do it. it will pass far wide of the planet. the third part of the strategy is last ditch, and that is being able to stop it violently, probably with a nuke, if everything else fails, and looks like it's going to be an impact. >> host: so, a lot of efforts to

find these things, congress passed a bill, put up some money. there are these programs you talk about, notably the linear program, and catalina observatory, pan stars, like that. i suppose there's another one that will come online in a few years, this lsst, the survey telescope. are those going to do the deal in terms of fining the asteroids or do we need to build more? >> guest: well, they should pretty well do it, but there's also, as i mention in the book, sentinel, which is an infrared telescope they're planning on putting -- in 2017, they're planning on putting into a venus-like orbit, from where it will watch the neighborhood, as i call it, and pick up anything, again, that looks threatening. you can't have too many eyes and

the community's in agreement on that. so everything you mentioned is in play, and sentinel should be in play, too. >> host: so, sentinel's funding is a going concern, it will be up there in 2017 far as we know? >> guest: that is the plan. it is being funded by a company in colorado, ball aero space and technologies corp, and the b-612 foundation, which is astronauts -- former astronauts rusty shrieker anded loop started with other people. they're actually going to build and it then it will get put into space. i think in 2017. that's the plan. so it's -- the private sector. >> host: so, the money we don't have and that we do need to protect the planet, then, is for the spacecraft that would go out and actually meet the beast. right? >> guest: exactly.

>> host: and there's no plan to build those things right now. is that correct? >> guest: well, it's being thought about. but is it concrete? no. it is all theory. >> host: and but for order of magnitude amount would those cost, do you think? >> guest: as far as i know that's not been determined but it's obviously multiple billions. but, again, what is your life worth? >> host: right. so, how probable is it -- what chance do people listening to this have of getting killed by an asteroid, by whatever else would come along -- how does that compare to whatever else would come along? >> guest: good question. the chances of getting knocked off by an asteroid are very, very, very slim. there is an inverse law here, and that is earth gets pelted

all the time, as you know, by everything from pebbles to boulders to larger rocks and so on. we're constantly being hit by any of so-called near-earth objects. the chances of the big one coming along which would be a planet killer, are very remote. they think the next time will be in 100 years, and by that time we should be prepared to do something about it. but as i say, it is the smaller ones that will ruin your day. they can take out large tracts of area, and it has happened, judging by the number of impact craters on the planet, it's happened well over 130 times. >> host: that's a random process so it could be happening in the next minute and we wouldn't know necessarily. >> guest: that's right. >> host: so, i read in the book

that getting killed by an asteroid is a little bit less probable than dying in an airplane crash. is that a fair statement? >> guest: that is absolutely right. it is the inverse law. the chances are very remote but if it happens, it can be devastating. >> host: so, i would guess that one result of this program so far, finding all these asteroids -- found a lot of asteroids with the monitoring programs that we actually now know that a lot of asteroids not going to hit us and haven't found any that will. so probably knock that probability down some. we're a little -- we know we're also safer than we knew before. is that a fair statement? >> guest: i think we're a lot safer, and there's another element to this, and that is the little prince who loved the asteroid he lived on, had a

point. asteroids are not all bad. asteroids have got some potentially very, very useful qualities. one is a lot of them are loaded with precious metals that can be mined. another is very big ones can be lived on, and that's in preparation for a lunar colony which is in the book. lunar colony being something i believe very strongly in. so the opinion is asteroids are a mixed bag. getting in close, turning into meteors, they can do terrible damage. it hand last year in russia, the town where one blew up over the town and sent more than 1400 people to the hospital, who were injured. so, there are pluses and minuses. >> host: fortunately didn't kill anybody. right? just a lot of flying broken glass and people being thrown around and things like that. >> guest: they were lucky it blew inwhere it blew up.

had it exploded over the city, at a lower altitude, it could have been horrendous death and destruction. >> host: i remember reading that in some way, while asteroids early in the history of the earth may have sterilized the planet over and over several times, that maybe actually they were sort of like our planetary life boat, that a big asteroid will throw things out into space, and some of these rocks may be infected by the early bacteria and such that were on the planet and then were sterilized but some of these bacteria can remain alive in space, capable of getting going again and reproducing, and those rocks -- a lot of them end back on earth. you have to have a really big asteroid to do that. you have to open up a vacuum

cavity in the atmosphere to get those rocks to fly out. so they are -- the destroyers and the creators perhaps. you said something also about people's ideas about asteroids and comets bringing in organic materials from outside. >> guest: that's a theory propounded -- it's oust my head now but comets in fact did bring life to this planet, which has not been disproven. >> host: yeah. it's not other theory that people talk about as much maybe, but, yes. so, how -- the audiences for this -- a candid question -- what fraction of the populace thinks -- knows the difference between an asteroid versus a comet versus a major planet or whatever? have you -- do you have any feel

for that? >> guest: my guess is that it's a very, very small percentage of the population. when i taught journalism at nyu i sent my reporting students out one day to interview the proverbial man in the street about what he or she thinks about the space program. and they came back and one said, professor burrows, the lady i talked to said she is more interested in educating her children. a man said, actually, i'm more interested in paying the mortgage. somebody else said putting food on the table. so the answer to your very good question is a very small percentage. people are worried about keeping their roof on, and i don't mean the roof that protects us against -- literally roof on the house and that's where it is. >> host: but it seems to me, at least in the recent past, congress has been motivated about this question. so, that is important. but are you thinking of how to

get the word out about this threat and how we need to spend more money than we are now? >> guest: that's why i wrote the book. i was privileged to be picked as the only nonscientist on the 14-member panel by the national research council, the national came of sciences, to be on a near-earth object survey and mitigation panel a few years back. we took testimony in washington, tucson, and santa fe, and that's how i got interested in this. they said it's a serious problem. again, dooms day ain't around the concerner. but i got interested in participating in it and was privileged to have been picked for it. it's a real problem as you well know. >> host: do you think they picked you because they knew you

would write a book like this? >> guest: yes. it was an act of faith. >> host: so, sitting here being somewhat depresssive, i could imagine all sorts of things that might wipe out the human race. people now think that, what, 71,000 years ago we were almost wiped by a giant volcano in indonesia or volcanos almost wiped out all life a quarter billions of years ago and i can imagine some really bad virus or something like that. so, is -- the asteroid threat really the worst thing we have to -- is it one of the tough ones? have you thought about that? >> guest: asteroid is one -- the minus thing about asteroids, big

ones can do a lot of damage. the good news is, they can be stopped. as the late gene shoemaker, geologist, and de facto planetary scientist, as he pointed out, asteroids can be stopped, hurricanes, typhoons, katie earthquakes can't. the good news they can be deflected or stopped, and that's part of, again, why i wrote the book. i should also said, back to your question, i'm advocating a permanent colony on me moon and mars. buzz aldrin, co-authored the book, called "rendezvous at tiber" in which the heroin is an

intergalactic space commander and she justifies an intergalactic multigenerational mission by saying, no place on this planet is safe forever. the universe is telling us, spread out or wait around and die, and that's the point. spread out. >> host: that's right. if you're on the moon, a dying volcano on earth won't get you. it's people you work with might leave you in a bad situation, but hopefully you figure out how to get along. so, you have a chapter on how to survive all of this stuff, and so -- except for the aliens. there's an alien vision -- they may know about the mom. anyway, stop kidding around. >> guest: one of the major points of the book is that

plantare defense has got to by definition by international. and i'm advocating we have a planetary defense agency. or nasa has a planetary defense department. the point is it's international and that's good. if we all work together, the bottom line is, on some level we are no longer americans and brits and russians and chinese and japanese. we are earthlings. >> host: the virus or volcano or asteroid won't know the difference. let me get a little bit technical about some things here. one thing i was surprised at, people talk about the torino and that is sort of a good way to lay out the threats and the probabilities or something, but is that like not used so much anymore or -- should we all be

getting a reading on the torino scale of asteroid threats? >> guest: as far is a know torino is just not talked about much anymore. for reasons don't know. they just not -- the community does not get the torino scale. but a lot of them have been measured and that's out there. >> host: yes. one thing i was wondering, reading about all these asteroids, this wonderful job of finding hundreds of thousands of new asteroids, and many of them are near earth asteroids, and one thing i was wondering, it's really much easier to find them around the plain of the solar system where most things orbit. do people -- have people

actually been searching the whole sky, including above and below the earth orbit, around the sun, as thoroughly or are we sort of missing parts of the sky? >> guest: not thoroughly. you being an astronomer, you know about the earth cloud. this cloud of rocks and things that surrounds the entire solar system, and a lot of these things are in there, and we can pretty well monitor the main asteroid belt, which is between mars and jupiter. there are untold, hundreds of thousands or millions, of rocks of all sizes in the main belt. and we can see them coming because -- we can see lot of them coming because of telescopes, because we're equipped to do that. the ones that drop out of the area above us we don't see coming. that's a whole separate category

and that is truly dangerous. there aren't many that come but if you can't see it, you can't defend against it, and that's a potential problem. >> host: okay. actually, what i was thinking of is the fact that rocks that have almost hit us might actually be the ones that are going to send a -- drop out of above or below the plain and come at us again. if there's a near miss, these things are going to tend to get thrown away from earth orbital plain but they will come back and hit earth obit. that's newtonian mechanics, they rush to the scene of the crime, and if we're there, then it's bad news for us, and those are the ones that are frequently going to be just coming out of the north or the south, without

maybe much warning. i was wondering if those have been covered by some of these surveys. >> guest: not many. and, again, you're absolutely right. they will come out of nowhere, with virtually no warning, and it's a real problem. >> host: that is the one that worries me, because it almost seems like there's -- well, a lot better to say you discovered 100,000 asteroids than to say you discovered ten thousand but, hey, covered the whole sky. and, so it is my impression, things like that are not covered yet. we got to -- well, first you have to look where you're going to find things, but eventually you're looking under the lamp post for the keys that you've

lost somewhere necessary the parking lot. >> guest: that's right. >> host: so that was one thing i was worried about and sounds like shy be a little by worried about that. we may be missing some of the ones that will surprise us some day. >> guest: as you know, being an astronomer, everybody in the community, as far as i know, believes that it's absolutely true. the other thing i was going to say of in terms of a near miss bay main belt asteroid, it will come around again, and that in that regard earth's gravity is bad because a -- an earth crosser will swing way out and because of earth's gravity it will come back and cross our path again. the deal is, as you know, is that every -- all things being equal, every time it comes by, it comes by closer. earth's gravity will tend to do that. >> host: i don't understand that. i mean, it's going to come back to organize orbit, -- earth

orbit but how does it know that earth is there? >> guest: i don't know. [laughter] >> host: okay. >> guest: but the chances are it will keep getting closer and that's a problem. >> host: i don't understand that one. we'll let that one go. so, what about all these mitigation techniques, three stages, depending on how big the thing is and how close it is to hitting earth. why don't you tell us a little bit more about those plans, at least, or this proposals. >> guest: that's the standard plan, and it, again, depends totally on seeing this thing at least two decades and hopefully more before it gets here. once it has been spotted and tracked, and it has been determined that it a potential

impacter, then you want to try and nudge it off course over a very long distance, and if that done work, again, blow it up. i should say in that regard, as you know, having read the book, coined a term called the bruce willis defense. and that comes from the movie "armageddon "in which i think eight days out he lanes on a comet and nukes and it saves the world. if you were to nuke a comet or an asteroid, a meteor, eight days out you would turn a cannonball into grape shot, and each one of those chunks could take out jersey city, or chicago, or nairobi. the bruise willis defense doesn't -- the bruce willus defense doesn't negotiating. again, you have to stop it decades ahead of time. >> host: we're going to take a break for a minute here and we'll come back. we have some more things to

discuss about the asteroid threat. >> on the go? "after words" is available via podcast through i-tunes and xml. visit book toe.org and select pod cast on the side of the page. listen to "after words" while you travel. >> host: we were talking about the break about the spacecraft, the space-based mode of attacking the asteroid or changing the asteroid, not just looking for asteroids. so there's deflecting it softly, deflecting it with a big blast or something, deflecting it

kinetically and just nuking it. the first thing is intriguing to people. how will you deflect it softly? like you're going to make good use of the butterfly effect. >> guest: the big story here is that, yes, thanks to astronomy, we can spot the danger. the other side of that coin is there is nothing in hand that will actually stop one of them. we don't have it. as a former newsman, the balloon over my head says, that's a very good story. we can spot them, we can't stop them. yes, you are supposed to be able to deflect it. that's the plan. do we have a rocket that can do that? no. and if we had a rocket that could do that and it didn't work, when it got in close and looked like it was going to

impact, could we blow it sustain do we have a mechanism for doing that? no. we certainly have nukes but how do you get the nuke to go out there and meet this thing several years out and blow it up? the technology is not there. so, the big deal there is, we're defenseless. yes, we can spot them but we cannot stop them, and if we see one headed this way tomorrow, we better get our act together very, very quickly, and try to get the technology in hand. >> host: what's the proposal for how we would deflect something just a little bit if we thought way ahead of time? say we had 20 years or something like that. >> guest: you would send a rocket out far ahead of time to meet it, and to nudge it off course, and then again, getting in closer, you would use nukes. i should say in this regard that, is a mention in the book,

there is the so-called "star wars" technology. i'm very proud to say that it was among the first people in this country to come out against that stuff. president reagan made a speech in march, 1983, based on what dr. teller told him about stopping russian missiles with this defensive system, and as they were saying at the time, there was supposed to be stabilizing. the point i made clear in foreign affairs, in 1984, within a few months of the speech, is that it was not going to be stabilizing. it would be destabilizing because if you have the only defensive system that works, you're going to try to lop off your enemy's head. so, the point is, that technology, which was very, very dangerous, in the cold war, is not going to be dangerous in terms of plantare defense. the asteroid, i.e. do not have

ballistic missiles to use to destroy us. they ain't commies, so what -- the point is, dust off the technology. nuclear pump x-ray lasers, and all sorts of things, to try and stop them. that technology would be very useful. >> host: so, like a nuclear powered laser, you would beam on to the asteroid and that would heat up stuff and just material blown out by being heated inwould cause the thing to rocket away into a different orbit, right? it that what you're talking about? >> guest: that's right. that's right. >> host: now, you were talking in the book about not even having to touch the asteroid with the spacecraft or with anything from the spacecraft, by

just using the gravity of the spacecraft, and that is something that is maybe practical if you have a couple decades lead time. >> guest: yes. they're calling it a gravity tracker, and again, the b-6-to 12 foundation, the southwest research institute who -- and aero space guy, they have talked about this for years and that's exactly right. you can deflect it by touching it or not by touching it, because it's so far out. again, at those distances, if you move it a couple of yards where it is 20 years out, it will miss the planet by many, many, many miles. so, distance is on your side.

>> host: the earth is only 4,000 miles in radius. you don't have to move it much more than that and you miss the planet altogether you. don't have to move it too much while your there for that to just continue. >> guest: that's right. >> host: there are lot of exotic ideas like painting the asteroid white or black or -- and so that the sunlight will push it or more or less in the gray asteroid that -- any of those make sense? >> guest: no. why sidle up to this thing and paint it color when with the same amount of effort you can nudge it off course? unless of course you were an art major, you might like that. but seriously, no. that's unnecessary. just nudge it off course, and

again, worst comes to worst, blow it away. put painting it colors is senseless. >> host: i mean, sorts of thing does affect asteroids but that's over thousands and millions of years. so do the math. not quick enough. >> guest: that's right. >> host: do we know enough about asteroids to be blowing them -- to be exploding things on them? you have a picture in the book of the asteroid, and it's what i guess you -- gene shoemaker says this looks like a bunch of rocks laying on top of each other, and what if all we managed to do is sort of like blow a hole in it or blow it in two pieces that are still on the same trajectory. do we know enough about

asteroids to do any -- the good thing about the gravity tractor is that will just work on anything, because gravity works the same on everything. we've known that. but when it comes to expecting an asteroid to react a certain way, what do we know? >> guest: it depends on the asteroid, and asteroids come in a lot of different compositions. some of them are almost entirely iron. almost pure metal. others are rocks. the popular image of the rock. i should say, all of them carry small craters or scars from impacts with other objects, which gets back to gene shoemaker's hail of bullets-as he called the universe in terms of what is going on out there. the point is, asteroids come in all shapes and sizes, and they vary enormously.

rubble piles are part of it. so it varies according to which one you're talking about, and the answer is, we don't know enough. that's why arrows, that mission a few years ago to land on one, worked and where the japanese did the same thing to try to get as much information as possible about our neighbors. >> host: does that mean that if we see one coming at us, the first thing we have to do is send a mission to it just to find out what it's like before we send the mission to move it? >> guest: that depends on how close it is. >> host: ya. >> guest: if it's 11:00, no. then you save earth any way you can but if it's very far way, yes, find out what it is in addition to everything else, the science builds up. you learn things about them. that is what is important. but again, it's a matter of how close it is.

>> host: right. so, how big and how close does something have to be when the only thing left is to nuke them? >> guest: that's a good question, too, and it depends not only on its size but on what it's made out of. my suspicion is that within five or six years, that's close enough, you have to allow for the fact that nuking it the first time may not work. the safety margin is as much time as possible. so what they're saying in the community is five, six, seven years to go out there and, again, blow it up. earlier, nudge it off course, but if you're going to blow it up, blow it up far ahead of time. again, don't turn a cannonball into grape shot. shrapnel. >> host: let me ask you about

the history of this idea. now, humans figured out there are rocks falling out of space, what, the end of the 1700s or something of that order? there's a famous quote that apparently thomas jefferson never said about he would rather believe that a yankee professor could lie than rocks could fall out of space. but apparently he never actually said that. but when did we first encounter the idea that a rock could fall out of space and actually kill somebody or kill a bunch of people or anything like this? how long has this notion been around? >> guest: well, since the late -- basically since the 18th century and the 19th. and it's astronomy that did it. the astronomers began spotting these things, and, again, you do a little bit of home and you see that the sky is full of them and

they're flying around in all directions. so it's a couple hundred years. before that it was all miraculous. things were falling out of the sky when the cavemen were around, but they put it down to god. and it was nothing you could do about it. like the phases of the moon. >> host: astronomers were talking about dangerous meteorites from the beginning, and i guess -- when did the science fiction writers get into this. >> guest: that came much later. look at galileo, 1610, be huts together the first telescope and trains it on the moon, and every telescope every been trained on the moon, including his, sees craters. it's rough, it's jagged, it's obviously been hit by things. that goes back to 1610. since then, we built on that.

i should also say, i wrote a book called "exploring poise" about the solar system exploration program, and we have had spacecraft, which i mentioned in the book, like vulnerabler, pioneer, mariner, voyager 2 did a sensational four planet grand tour in the 1970s and '8s so. every -- the four planets being jupiter, saturn, uranus and neptune. every one of the moons it passed had craters. again, it sent back this stuff. nobody talk about it at the meetings because the science was so wonderful -- i was at those meetings at the near encounters, the science was so wonderful that's what they wanted to talk about, the jpl. not about cal tech -- at cal tech, not about the damage, what the -- but the pictures were there horrendous scars and

craters by every solid object those spacecraft pass. >> host: it's such a universal process. there are some -- obviously if you have a very thick atmosphere, that keeps craters from being formed, and there are some places that are just volcano world. that's the minority. mose places are getting pelted by these objects all the time. all these objects all the time, and in fact it's an amazing tool because things get hit at a certain rate and once we figured out what the rate was by measuring the ages of features on the moon, from the apollo program, you could extend that to all the other objects that were being pelted. so this is sort of like -- hugh do you look at the surface of a planet and tell how old it is? this is kind of how. without going down and picking up a sample and dating the rock,

you can just look at it and it's a wonderful tool. so, yeah, you've got your volume can know world. you -- volcano world, your impact world, and the moon going back anding for. -- going back anding for. they thought it was volcanos for a while, and then balled win started -- baldwin started convincing people it was impact, and then shoemaker really convincing everybody. >> guest: don't forget the crater off yucatan, which they also felt was a volcano at one point. >> host: that remind me that volcano world, most of the surface of our planet gets resurfaced. it's like the ocean bottoms get -- they've been resurfaced

50 times since the beginning of the planet, and the impacts get eroded away on the continents and we have a lot of volcanos and they're dangerous. the theory is that at least the whole human race almost died because of the volcanos, and we're entering the 21st 21st century, and who knows what we're going to cook up in the way of dangerous things that could kill us all. so, going to return back to this issue that you raise, the survival imperative, the name of your chapter? along with protecting ourselves from the as steroids that -- asteroids we have to protect ourselves from everything else. so one thing you're advocating is, let's get some people out of here, and so why don't you tell me more about that.

>> guest: spread out or die. there is safety in spreading out and that's why we should have a lunar colony. it's not for adventure, although the -- certainly an interesting thing to do. spread out or die. that is why we need to do that. in terms of volcanos, again, getting back to gene shoemaker, the good news at asteroids is that they can be defended against weapon can't defend against volcanos. as he pointed out, or, again, earthquakes, typhoon, hurricanes. there's no defense against that. so, i'm an optimist in that regard. i you have the will, you can defend the planet against asteroids. you can't defend it against exploding volcanos. you just can't do it. so, in a way we are sitting on a powder keg. >> host: have you thought about,

like, -- okay, we put some people -- we put neil and buzz on the moon and if a volcano had gone off while they were there they other would have been in bad shape may. have been able to make it back to the pacific ocean but maybe there wouldn't be an aircraft carrier to pick them up or something like that. so, talked about saving the earth from asteroids. how a big project is keeping enough people alive on the moon? and by the way, this is something that i'm willing to entertain because this is what i wrote about. but what do you think? >> guest: in terms of a colony on the moon? >> host: yes. >> guest: it's a no-brainer. spread out or die. and, again, will cost a huge amount of money? yes. what is your life worth? >> host: yes. you're thinking -- you don't have any sort of scale or proposal in mind or something

like that? you just have to keep some people alive there that can come back to earth. >> guest: you know, arthur c clarke wrote about this in his third back, which is a bible in the community, and he's got -- he mentions a lunar colony and a mars colony and he's got the mars colony under a colassal plexiglass dome and you can see vegetation and automobiles. the dome has to keep out raidation which on mars is terrible. but again, what choice do you have? one really bad lit and earth is -- bad hit and earth is gone and we just evaporate. will the universe care? no. but i care. i've got grandchildren. >> host: it's not just the

volcanos and asteroids. you can think of any number of things getting out of hand. it's lucky we made it through the colored war. >> guest: and terrorists. look at the stuff we're pouring into the ocean, and air pollution and global warming and climate change. absolutely. what is the old line, we have met the enemy and he is us. >> host: what i think is you have to have a lot of people to maintain a society such that when the threat is gone, and the earth is settled back down into something like normal, to get a bunch back to earth so that they could start the place going again in terms of civilization, you'd have to have a lot of of people on the moon, and you can talk about the numbers but it's in the many thousands, many hundred thousand or something like that. we're going to build housing for

100,000 people on the moon. that sounds very expensive. but the thing that's so cool is that on the moon, and on mars, we have discovered recently that there are actually these basically caverns just underneath the surface, and that's where you have to go. you think, every million years or something, some horrible impact occurs on earth. well, there's any number of things on the moon that would kill you every day, and -- but the way to get away from them is just to go underground a little bit. you can seal out the vacuum. don't have to worry about the radiation from the sun and the galaxy. don't have to worry about the temperature going up and down by 500 degrees fahrenheit. all these things don't make it below the surface, and below the

surface there are these giant spaces, and if you do the math, you ask how many people could you put in those spaces, and keep them alive, the heat and et cetera, it's in the millions. so actually it's not so crazy an idea. you don't have to build a city of 100,000 out in the vacuum. we already have the superstructure sitting below the moon. >> guest: right. >> host: so, you have to get the people there and have to give them the tools to sort of make things themselves, and they'll take care of it. people are pretty good at making liveable conditions especially if they're increasing in number and want their children to live somewhere decent and such like that.

and the fascinating things, these same kind of caverns are on mars. so, it's maybe not such a crazy idea. it would certainly be very, very expensive, but it's not as expensive as when you first think about how much it might cost. >> guest: that's right. there's another element that should be mentioned and that is what some friends of mine and i call an archive. the record of our collective civilization also ought to be preserved. we don't want to happen -- if there is a calamity on earth, we don't want to happen to the planet what happened to the great library of alexandria, when the record of civilization was lost in a fire. so, we need an archive of our civilization, which is constantly updated, and either of the polls and offplan