Could We Survive An Asteroid Collision? | Final Target | Spark

march 12 1998 american astronomers shocked the world by reporting that a large asteroid could potentially hit the earth within 30 years could humanity survive the impact of such an asteroid at this time there is no definitive means to protect or defend ourselves from the inevitable global devastation that this event would ultimately cause this program profiles some of the most spectacular comet and asteroid impacts on the earth as well as the current and future dangers of such impacts to the survival of the human race also portrayed are the current measures that space programs have already set up to observe detect locate and track these celestial objects near the earth that may someday pose a distinct threat [Music] future plans include the sending of robotic spacecraft and even human exploration missions to any threatening asteroids or comets in order to deflect or destroy them [Music] important as the continuing reign of comets and asteroids is on the earth today it is nothing compared to the conditions at the birth of our planet four and a half billion years ago then the earth itself formed from an accumulation of cometary and asteroidal debris and some of those impactors were extremely large you look at the moon it's heavily cratered if you look at mars heavily cratered mercury's heavily cratered the earth is was also heavily cratered it's just that here on earth the effect of all the erosional processes and the tectonic processes which create mountains and earthquakes have erased the record uh but in fact the earth would have looked just like those other bodies had it not been for the weathering and the tectonic processes the geophysical processes very early in the earth's history we are fairly sure it was struck by an object about the size of the planet mars which ruptured the planet ejected a great deal of material into orbit around the earth and it is that ejected material from a giant impact that ultimately formed the moon moon of course is pockmarked by craters upon craters most of these however were created back in the early days of the formation of the solar system and uh when there were there was a lot more material hitting both the earth and the moon um there is not much of that material left so the moon does not have as many recent craters but certainly there are recent craters on both the earth and the moon and cultures as diverse as the ancient greek the ancient mayan the ancient chinese those cultures didn't interact at all but they all feared comets and into the middle ages when the the church was well established they utilized this fear suggesting that comets were warning signs shot at a sinful earth from the right hand of an avenging god and then in the 17th century when halle and newton showed that comets are not warning signs from an angry god but in fact celestial objects moving around the sun just like the planets the fear of comets was sort of transferred from a sign of an impending disaster to the actual agents of disaster [Applause] the largest well-documented impact was 65 million years ago we don't know if it was a comet or an asteroid but we do know that it struck the earth in the yucatan region of mexico producing a crater about 150 miles across and that it created such a profound environmental catastrophe that most life on earth came to an end the majority of the species went extinct including the dinosaurs there's a local crater here in the united states in arizona that was created by something a little smaller we think about 150 feet in diameter 50 meters that is the meteor crater near flagstaff arizona and it did create a crater because it was uh the the asteroid was iron very solid very massive it made it all the way through the atmosphere and created a crater that is um almost a mile in diameter 1.2 kilometers i think and about 200 feet deep there have been several instances of comets and asteroids smacking the earth the most recent perhaps is the so-called tunguska event in russian siberia where in 1908 an object probably the size of several houses smacked into the earth's atmosphere and caused an explosion that knocked down trees for 30 miles in either direction and this was an object that was only about 60 meters in size just over the half the size of a football field and it didn't even hit the earth because it broke up in the earth's atmosphere there are countless craters all over the earth uh it's really surprising we probably uh know of only a small tiny fraction of all the craters that have been created by impacts most of them have been eroded away and are very difficult to find we know of something like about 130 to 150 craters currently on the earth the earth orbits the sun in a sort of cosmic shooting gallery with comets and asteroids coming by all the time at any particular moment there's likely to be one or two between us and the moon that are 30 or 40 feet in diameter or larger we don't usually distinguish between comets and asteroids because once it hits it really doesn't matter what it was asteroids are made of rocky material comets are made of icy material but if you're hit by one it really doesn't matter any more than you would care if you were shot whether the bullet that shot you was made of lead or steel there are there are millions of asteroids out there most of them are small and it's the asteroids that are one kilometer half a mile or so and larger that we really want to make sure we uh detect and catalog and we know only about 10 of those so the current search efforts are focusing on those rather larger asteroids but there are many more smaller ones and in fact every day little asteroids pass the earth we simply don't we don't see them we know so little about these arcs that we don't even know whether they're all traveling in the same direction or what their orbits are we don't know if they have very highly inclined orbits relative to the plane where all the planets travel we don't know hardly anything about these asteroids that come in and that are very difficult to detect these are basic questions where are they going and where are they coming from we don't know the answer there are about two thousand we believe there are about two thousand objects which are potentially hazardous to the earth of those we know about ten percent and we're learning about one percent more every year at the current program level if nasa were to increase the program level uh we could probably complete the inventory in about 10 years it's just that we simply have only looked at and found 10 percent of the esti i hate to say this of the estimated population of near-earth asteroids we estimate that there's between a thousand and two thousand very widespread the point is we now know of over a hundred asteroids which we call potentially hazardous objects and by definition that means that these objects can come within 5 million miles of the earth [Music] the velocity of these comets and asteroids depends on their distance from the sun the fastest objects in the solar system are probably comets they come in from deep outside the solar system and they arrive at the earth's orbit with velocities that can reach 73 kilometers per second that's about 73 times faster than the fastest high-speed bullet in contrast to the apology approximately after three days to go from moon to the earth a typical comet would take something like an hour and a half to three hours to travel the same distance something that you think is coming towards you particularly something that can get from the moon's orbit to the earth's surface in under three hours five million miles is not all that far [Music] fortunately we on earth have an atmosphere that protects us from small impacts so we don't have the sort of daily rain of dust sized particles that the astronauts experienced on the moon however the atmosphere is of no use in protecting us it provides us no shield from the big impacts those that are really hazardous a comet or asteroid a mile across punches through the earth's atmosphere just like a fist through a cobweb it might as well not be there [Music] if an object as large as 10 miles across it's the earth then it causes enough havoc to wipe out a good fraction of the life forms on the planet but these events are very rare these are maybe several tens of millions of years apart on average extremely rare much more common events are impacts by much smaller bodies it's like kilometer sized objects there are probably one to two thousand of these that can conceivably impact the earth and if one of them hits it will be much less catastrophic than the kind of an impact that can wipe out lots of life forms but nonetheless it will be terrible and probably will end civilization the reason we are concerned about impacts of objects even as small as a mile or two across is that it turns out that the earth's ecological system its environment is very fragile these are not impacts that make any difference to the planet as a whole they don't change our orbit they don't change our spin they don't change the axis of rotation they're nothing to the plant as a whole but the impacts are able to produce environmental catastrophe it's really a measure of just how sensitive the balance is that allows life to flourish on earth we should have in the case of a comet perhaps a year or two to react in the case of an asteroid we should literally have decades so uh with an asteroid we should have plenty of time in fact the technology we have today is probably not the technology that we will actually use because the event is likely to be some time off when our technology will be much more advanced than it is today i've done research in into this area i took the comet yakutake in fact as an example that was a comet that passed by the earth in 1996 and it passed fairly close to the earth astronomically speaking the comet was only discovered three months before it passed by um the answer to the question really is that we couldn't predict that it would hit the earth until about a month before the event and that is probably typical most comets are not discovered until about three months before they pass by the sun so we're talking about months here many of these objects are whizzing by us daily and we won't know when the next one happens quite likely unless we have a good campaign of searching for all of the objects and cataloging them we may miss them entirely and and the next impact could happen entirely tomorrow in general the astronomers look at maybe 10 or 15 percent of the sky so most things coming in would be missed if you ask the question at today's level of effort uh what warning we would be likely to have of the next impact the most likely warning is zero the first you would know about it is when you felt the ground shake and saw the the plume of hot rock vapor coming up over the horizon whenever uh somebody in a level at a high level within the military would raise this planetary defense issue should we the military be worried about objects from outer space smacking into the earth uh their colleagues would always start snickering and giggling and saying oh no here we go it's a chicken little defense we don't have to worry about this and and so that happened a lot ten years ago and it's happening much less now probably because of comet shoemaker dv9 smacking so dramatically into jupiter in july of 1994 if it could happen to jupiter it certainly can happen to the earth the impact of shoemaker levy on jupiter several years ago was a very important experimental laboratory for us because these are very rare events uh impacts with earth of this magnitude are very rare fortunately so here is an opportunity to observe the impact of many fragments of a comment actually on another giant planet the total amount of energy deposited by these fragments of shoemaker levy were millions of megatons so this was much more than just a single hydrogen bomb these are massive eruptive energy energy deposits creating these huge plumes we could see the 20 odd impact sites as little clouds of dust essentially the comet was vaporized when it hit the atmosphere and these dark clouds on jupiter's atmosphere and the rings around them were larger than the earth in size should a comet or a large asteroid strike the earth the devastation would be immediate and sustained there would be long periods of very dark weather the sunlight would be shut down the impact will produce devastation immediately where it occurs but it can throw up a lot of material that gets vaporized rocks are thrown up much of it out of the atmosphere and a lot of this stuff will then spread out but come back down in a much larger area when it comes down it will produce firestorms because material is very hot it'll produce a smaller impacts but impacts as well it will throw up a lot of the dust will remain in the atmosphere some of the effects that we would expect would be that the dust generated from this enormous explosion would float up into the earth's atmosphere surround the earth shut down the sunlight so things would get much colder than they are now the plants the food chain would be disrupted because the plants no longer would have enough sunlight it would be a pretty nasty situation in terms of the human species as a whole in the immediate after effects of the impact it's in water it's a lot worse because the human population tends to be around the coastline and anything that big hitting the ocean is going to create a tidal wave that's going to make the manhattan skyline with puny uh you're literally going to see salt water and tidal waves coming in hundreds and hundreds and hundreds of miles in the coastlines if you're in that area um i one hopes one has that you've gotten your affairs in order and it made your major peace because there's no chance [Music] impacts represent a natural hazard in some ways they're just like hurricanes and earthquakes and volcanic eruptions they're part of nature they've been with us all along but they are different in two important respects first only cosmic impacts are large enough to threaten the survival of humanity or to possibly create mass extinctions no imaginable level of earthquakes or volcanoes or any other kind of natural hazard has the potential for killing billions of people at one time the second distinction is that they are the only natural hazard that we have the potential of doing something about there's no one that can imagine a way that you could stop an earthquake from happening or tame a hurricane or plug up a volcano but if we had adequate warning of a comet or an asteroid headed toward the earth then we do have the technology to deflect it to change its orbit so it would miss the first thing we do is to identify the entire population of potential threatening objects there are search systems in place now the neat project between jpl and the air force is in place and they're discovering north objects and there's a program at the lowell observatory that's coming online so the first order of business is to find out the entire population of potential earth threatening objects the large ones that are larger than say a mile or so in diameter we only know 15 percent of that population now neat is a observing program an electronic detection system that allows us to search the skies as rapidly as we can with charge-coupled devices on a one meter telescope each night from the jet propulsion laboratory we prepare an observing list of those fields in the sky we want to cover for that night of 10 plus hours [Music] the telescope is located at the air force observatory in haleakala hawaii which is a mountain in maui and every run when the when the moon becomes new we're able to search the skies at this darkest time and somebody there mounts the instrument on the telescope connects the electronic camera to the back of the telescope and then the computer takes over from then on it automatically controls the telescope and controls this electronic camera and finds these moving stars and the images recorded by the camera this is automated asteroid detection initially when an object is discovered it's just a speck on a picture really electronic picture nowadays and typically it might have a little coma around it if it's a comet you don't have any idea how far away it is you have to take a series of images over many days in order to get any idea of where the object is going but using mathematics and the well-known newton's equations of motion you can determine what the orbit is very crudely after say a week of observing an object the first step in terms of addressing any potential impact is to very accurately determine what its trajectory is so we can be sure of exactly the or tractor it's on and when when and where it might impact and how long we have that is the very first step and certainly for that step jpl would be heavily involved because of the capability we have to do these inventories which we're doing today it's just that we have each night five or six hundred new asteroids we cannot start checking out orbits on all of these of course we occasionally do get a little impatient and we will run orbits of those we're most eager about finding out what the preliminary orbit is we have a good sense of based upon its motion and where it's located in the sky as to whether it's going to be a near approacher now it's important if it's a dangerous a dangerous object something that appears to be coming close it's important to keep tracking that object because the longer you track it the more observations you take of this the more pictures you take over an extended time the better you know its orbit and we really need to know a precise orbit in order to predict whether it will hit the earth and if it will you know when it will hit and where it will hit and that sort of thing suppose we discovered an asteroid that looked like it might be on a collision course with earth during the next 10 or 20 or 30 years the very first thing we would do would be to try to do radar observations as well as more extended optical observations to shrink the uncertainties in the orbit and find out if it really was going to hit this would be possible over a period of years it would not be possible over a period of months so we would have to have at least a few decades at least a decade or two of warning to do this really right but then suppose we got to the point where we knew an asteroid was going to hit the earth and then we would decide what strategy we're going to use to protect ourselves comets long period comets in particular provide a greater problem first of all because they are coming at us from the depths of space where we can't really see them until they approach secondly they're they're dark objects to begin with they're traveling very fast when they pass the earth two to three times faster than an asteroid would pass the earth and finally they have this uh outgassing characteristic where they where the frozen gases inside the object spew out as as if from geysers and that tends to move the trajectory around that will actually push them and change their course slightly slightly but enough that over time it may create a hit or miss so they are very difficult and we cannot be sure until a month or two before it passes the earth whether or not it would hit the earth for a comet once you have identified a potentially hostile comet or asteroid then with decades of warning you would have the opportunity to investigate it you'd send a spacecraft like the current nasa near mission which is going to a near-earth asteroid you would measure its size its rotation its shape its composition whether it was one solid rock or a rubble pile try to find out what it was like we can't just send up a rocket and set off a bomb because for example we don't know if the object is two objects in orbit around a common center of mass it might be a binary asteroid even if it's a single object we don't know its interior properties and the response of the object to a bomb is going to depend in detail on its interior properties whether it's fractured down the middle whether it is two objects in contact we really could be making a huge mistake if we just send a bomb up there to deflect it without exploring it in great detail so what we're going to have to do is probably send a whole fleet of robots to inspect the object [Music] if you do decide that you want to move a company or an asteroid that you want to to move it aside so it's not going to work um the only way we have to do it is with moves you're not going to do it with lasers you're not going to do it with particle beams you're not going to go out there and attach a little rocket engine it's an enormous amount of mass for anything that we're actually going to be worried about and you have to move it uh the only way to get that kind of concentrated energy especially in the kind of missile or spacecraft that we can monitor current technology the only way to do that is and big ones and lots of them one obviously must be careful in trying to apply any sort of defensive system and in particular in setting off a nuclear bomb as a way to deflect the orbit if you hit it with a nuclear bomb if you use too big a bomb there's a danger that you would break the object apart and increase your danger actually because now the earth might be hit by several objects instead of one sort of changing a cannonball into a cluster bomb we would probably have to send some sort of a nuclear weapon into space set it off one asteroid radius off the surface and ablate the material on the front side of that asteroid so it actually acts as a rocket-like engine and pushes the asteroid aside just a bit so that in 20 years when it's predicted to hit the earth it doesn't hit the earth because we've modified its trajectory just enough so it misses the earth in 20 years time if you use small explosives if you set them off not on the surface but in space nearby the object you can apply very gentle pushes at least we think so we've never done this this is just theory and so i'm telling you what i think our technology could do but i don't pretend that this is a mature technology and that we would be ready tomorrow to try to defend ourselves if an incoming object were discovered there are of course treaties that forbid nuclear weapons in space and so this would have to be a international process whereby this these weapons are delivered to the asteroid and this this asteroid is slowed down but uh after all the threat is an international threat it isn't going to hit new york or los angeles or moscow it's going to hit everywhere we might even have to send people there very quickly to set up seismometers on the surface to determine the gravity field to try to psych out what the interior is like before we ignite a nuclear bomb now there's a nightmare scenario here because all asteroids have suffered collisions and they're all fractured and we know for example that some of these objects are two lobes touching each other in that kind of a situation if we set off a bomb near one lobe we'll destroy it completely but we know that we would not do anything to the other lobe we wouldn't even change its orbit so we could go to all this work we could set off a powerful nuclear weapon and it would not save us except for the minor problem of needing to bring them back uh humans would be ideal for a situation like this and from the standpoint of being more dexterous more intelligent more able to make decisions on the fly and more able to generally react to the situation that they find than a robotic device would be but when it comes to to the other side of the equation which is that supporting humans uh for a long space flight is is a is a big problem and of course in in the situation where you're trying to save the earth you would you would take a lot of chances you would cut a lot of corners but probably the biggest single thing that would make humans not an attractive option for this is the need to try and bring them back and so we're sitting here we don't know anything at all about the object we have to make decisions about what launch vehicle to use what kind of a nuclear device to use what its total energy yield should be what the timing should be how this big project is going to be orchestrated and so forth and yet we don't know enough about the enemy moreover we can't learn enough about the enemy without sending a whole bunch of spacecraft to it we might not be able to learn enough about the enemy without sending human beings to the object unfortunately i think if we were to have this kind of event an awful lot of the training that we conventionally do for the things that we do now which includes rendezvous proximity operations spacewalks working with tools outside handling of large objects all that would be applicable to the kind of mission that you would put together if you decided that you were going to try and stop a comet by going and landing on it and or docking with it really and blowing it up or trying to deflect it by placing charges the stuff we're doing now for space station would be as applicable as anything for that [Music] it's going to be much more like some of the early lunar landings where they had to take over computer control and redirect lander away from those boulders into something that was much more smooth but it's going to be that to to a much greater degree we're mostly not quite that suicidal so i i think that you'd find you'd find that most people would want to want to have some chance of getting back but again the the the idea is that the world is in danger and so these people are obviously prepared to take a lot of risk and and i think it's i think it's fair to say that most of the people that i know who are in the astronaut corps have something of that in their characters that they wouldn't have volunteered for what is inherently something of a risky business to start with so it's a little riskier than what we do on an everyday basis but it's the same kind of focus [Music] [Applause] [Music] the recognition of an impact hazard is a real natural hazard and something we should perhaps worry about it's quite new it's only in the last few years so far the u.s congress has has commented on it the parliament of the european union has there have been a number of meetings but no one has clearly stepped up and taken a leadership role and said we should spend the money and we should carry out the survey i hope that there will be increasing interest on an international level in doing that but we aren't quite there yet most people do not see this do not understand this threat and one can understand that response because the threat is very unlike anything else in human experience it's really very new idea and it takes a while to get used to it i think the scientific community has a job on its hands to educate the public as to this this threat of comets and asteroids i mean every day you have car accidents people can identify with those every few months we have airplane accidents people can identify with those and so these are perceived as real threats but when you talk to the public and say there's perhaps going to be a large impact of a comet or an asteroid most people will say well why don't we wait 250 000 years and then worry about it but what the education process we have to go through is that this could happen tomorrow morning or it could happen three million years from now and this is the education process that we have to go through to educate the public and the congress to this type of threat and so the proper resources can be put forward and they're very modest levels of resources for finding the entire population of earth-threatening objects and keeping an eye on them there are a few astronomers who make a profession of scanning the sky with advanced telescopes looking for potentially threatening comets and asteroids it's very few in fact the total number of people involved in searching the sky is less than the staff of one mcdonald's restaurant that is the level at which we the people of planet earth have taken this issue and are trying to solve it so the proposal that has been developed first by the nasa study and then by international bodies is to carry out what we call a space guard survey a simple telescopic survey to look for potentially threatening objects it would cost about 10 million dollars a year for 10 years at the end of 10 years we'd be able to answer at least at the 90 percent level the question is there something coming our way that poses a threat to the planet or is there not one normally has homeowners insurance to pay for protection against very unlikely but potentially catastrophic events the asteroid comet collision hazard is similar the potential catastrophe from one of these impacts is very large but fortunately the insurance that we need to protect against most of that risk is very cheap it's a tiny fraction it's less than one thousandth of the budget of nasa for example it's a tiny amount of money with enormous return on the investment [Music] i think it's imperative that the public and our government understand the serious nature of this possible threat the only way we can evaluate how serious this might be is that we have to complete the survey of the skies a comprehensive sky survey probably for at least 10 years with multiple telescopes in order to evaluate whether we have some concern based upon our near-earth objects and i think this is probably the most important aspect of this work is to bring home the message that we simply do not have a good grasp of our our nearest neighbors in space we want to find them before they find us the cost of the space station ultimately will be at the 10 billion level the cost of a human mission to mars ultimately will be at the 100 billion dollar level and all these costs are huge compared to the several million dollar price tag on a really high powered optical system to discover the possibly threatening earth crossing asteroids we have tried to interest governments around the world in providing the minimal support that would be needed to do this job right and we have failed i think the decision makers either do not really understand the simple facts or they simply don't care or in the democracies i think the governments believe that the people don't care we we spend so much more on other rather trivial things that this this is as i say a very inexpensive way to allow the scientists to identify whether there's a menace out there and if there is have enough time to make our planned diversionary methods so this object will not strike the earth and we will suffer the consequences as the dinosaurs did 65 million years ago [Music] i think most people who really understand the science of near-earth objects all the characteristics of the hazard all the potential of these objects are at once very excited by it and befuddled by the reluctance of the governments of the technologically adept countries of the world with big space programs to fund this work it's a mystery to put it in perspective i mean these impacts deep impacts like in the movie of very large objects are very rare events they don't happen that often it's what we're buying if we if we go out and look for things there's certainly some science but we're also buying insurance uh and and as insurance uh what is it worth to prevent the one in a million chance that all life as we know will end the comments and asteroids are not only interesting because they pose a potential threat to the earth they're scientifically important because they represent the leftover bits and pieces from the early solar system formation process so if we wish to study our origins from what chemical mix did the earth ultimately evolve then studying comets and asteroids are the way to do that because of the most primitive least change objects in the solar system we've flown by two asteroids already galileo did that on its way to jupiter galileo arrived at jupiter in december of 1995 but on its way there it flew by two asteroids and gave us our first close-up view of these bodies in outer space and we even discovered that one of the asteroids had its own small moon [Music] the asteroids offer resources for titanium for iron so if we want to build structures in space we don't build them on the earth and then take them to space we build them in space mining the asteroids it's been estimated that if you take all the resources of the asteroids between mars and jupiter and in terms of today's dollars the titanium the iron the cobalt that is available it works out to something like 20 billion dollars for every man woman and child on the earth's surface it's extraordinary we're starting to appreciate all the reasons why the earth crossing asteroids are important because of the threat that they pose also because of the promise that they hold i think that we're living in that era of discovery and i also think that the one the singular event that would mark our place in history would be a mission of people to land on a near-earth asteroid and this could be done within the next 10 years it would be dramatically cheaper than a mission to mars dramatically easier than a mission to mars and it would be the first step off of our planet into the solar system to these worlds that really are just huge numbers of space stations waiting to be inhabited [Music] if mankind is ever to move off the earth's surface and start colonizing space then we're going to need metals we're going to need rocket fuel and rocket fuel is nothing but hydrogen and oxygen as an oxidizer and these are found in abundance in water and water ice is found in abundance in comets we're going to be launching another mission called stardust in january of 99 that mission is designed to capture some dust of the comets of a comet as it flies through the comet tail collect that dust and bring it back to earth in january 06 so that we can analyze what this black organic like material is that coats the comets in the solar system and so in the next century i firmly convinced that the the asteroids and the comets will be utilized as resources as mankind steps off the earth's surface and and into the great uh interplanetary ocean [Music] the best way to make sure the human race is wiped out by a large object hitting the earth is to make sure we aren't all here i believe that the best hope for mankind is to move ourselves obviously not too many of us at a time can go to start with but off the earth and and get going on out into the into the solar system and on eventually to the stars it's interesting to me that we have a society that can it can absorb a limitless amount of star trek and all the other uh futuristic stuff that we see in movies and television and yet we don't spend very much of of our real today money taking even the baby steps that it takes to make true interplanetary exploration possible and believe me in the in the great scheme of things we're far more likely to preserve the human race by making sure we aren't all here when the comet hits than we are by trying to do something to stop it every part of our planet is equally subject to impacts there's no place that that is more likely to be hit or less likely to be hit and when it comes to the big ones the ones bigger than a mile across it really doesn't matter where they hit if the earth were hit by an object a few miles across it would ruin your whole day or your whole year no matter where it hit and that's one reason that there has been so much international interest it's uh it's one of the things that threatens the whole planet equally and it seems reasonable that any solution that society comes up to ought to be an international solution everyone's equally at risk and every country can contribute to solving the problem if the human species is to have any chances of survival in the future the first step is to increase our awareness of the global threat of a comet or asteroid impact then to be able to set up the necessary defensive procedures in order to avert such a disaster [Music] at present we cannot even locate all of the potentially dangerous objects in space the ability to defend ourselves from the civilization-ending danger does not yet exist it is only in its infancy of planning and development the dinosaurs could only feel the ground shake and watch the plume of impact dust coming up over the horizon just before the resulting global catastrophe caused them to freeze and starve [Music] [Applause] if we cannot learn from the past then humanity as a whole is doomed to experience the same exact fate as the dinosaurs that can come as early as tomorrow morning

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Keywords: Spark, Science, Technology, Engineering, Learning, How To, education, documentary, factual, mind blown, construction, building, full documentary, space documentary, bbc documentary, Science documentary, asteroid hit earth, what if, how to survive an asteroid, end of the world, survival videos, asteroid impact, asteroid impact video, how to survive an asteroid strike

Id: r-uiKJvdzzk

Length: 47min 50sec (2870 seconds)

Published: Sat Aug 22 2020