CCNet SPECIAL, 16 October 2000

- A shorter version of this interview, made a few weeks before the Task Force Report was released, was published in the German weekly DIE ZEIT (15 September 2000).


JK: Let me begin with a very simple question, Sir Crispin: why did the British Government decide  to set up such a Task Force suddenly, out of the blue?

CT: Well, it's a good question. Some people thought that the British Government had access to some threat that was not known to the general public and this was a sort of panic measure. In fact it wasn't. It was the product of the substantial research that has been done over the last few years, greater understanding of the nature of the problem and - perhaps most important of all - debate in the House of Commons in March 1999, when the matter was very thoroughly gone into.  People began to laugh at the idea, but they ended by being quite serious about it. So I think the Minister of Science, Lord Sainsbury, decided that it would be a wise thing to do to set up a Task Force to go into details and to look at things very carefully.

JK: But why Britain? To give a good example to other countries or because they are more aware of the problem?

CT: I suppose in some respects astronomy has always been a particular British interest and we have made great contributions to astronomy in the past with a lot of distinguished astronomers. It seemed just useful that we should look into the issue and make recommendations. It is quite obvious from our terms of reference that we are looking into how this matter can be carried forward to the international <arena as well. Thus the Task Force was - I quote from its terms of reference - it was asked to 'confirm the nature of hazard and potential levels of risk, to identity the current contribution to international efforts and advice the Government about what further action to take, and how the issue should be communicated to the public.' So we are not going to set up an all-British effort to determine the subject, determine the threat,  but considering what is the most useful British contribution to what must be an international effort in which, of course, the great leader at the moment is the US.

JK: The Task Force was set up at the beginning of this year, the Year 2000. You have prepared a report. Could you give us the gist of that?

CT: We were given 6 months to investigate the problem and come up with our recommendations, which means that it is not going to be an immensely detailed piece of work. It is really a six  months look at a very complicated problem in which, as one of the 3 members of the task force, I find that the problem is not lack of information, but it is how to make sense of the enormous quantity of information that is now available. And we have tried to do that

JK: So first you locked at the potential risk. Can it be quantified?

CT: I suppose you could put it like this: our first task really was to identify what is the problem and look at some of the history of near earth objects impacts with the earth. There had been such impacts throughout history, and nowadays we understand much better than before exactly what has been going on. I mean the more we got into it, the more interesting, of course, we found it. Perhaps, if I can mention a couple of examples. When I was in the US recently, I was in the Pentagon, and the Americans referred to a little impact on the 18th of January. Well, that wasn't published in Europe, although I think it is now generally known, where an object that had something like 5 m in diameter exploded over the Yukon and showered the place with bits, it emitted a lot of light, made a bang and more important, it distracted radio communications. So that was only 5 m in diameter, that happened this year. Then you find that over the last 10 years there have been a succession of events which haven't on the whole been noticed by the general public. The general public did notice of course the impact of the comet Shoemaker-Levy on Jupiter in 1994 when it created a fireball as big as the earth.  And that was another factor, I think, which caused great public interest. It was a warning sign, it showed people what could happen if - and it attracted a lot of interest. And since then more evidence comes out every day about the impact of 1000s of tons of dust that are entering the earth's atmosphere which is not, I think, common knowledge. And then we looked back at some of the bigger impacts just during this century, and you will find that there was quite a large object hit the Brazilian rain forest in 1930, another hit Guyana in 1935, and, as every knows, there was a major impact in 1908 when an object about 50 m in diameter exploded over Tunguska in Siberia. Now a little calculation which shows how important that is, is that had that object struck an inhabited area such as London or Berlin or anywhere else, it would have done tremendous damage. Indeed, had that object hit London in 1908 and not the Siberian forest, it would have eliminated all of London within the outer ring road of the M25.

JK: Isn't it true that the scientific community has, for quite a long time, been and still is resitsing the idea that the history of mankind, not only the history of this planet, has been shaped much more heavily by impacts, by bombardment from space, because this runs against the idea of slow progressive evolutionary development.  Is there not still quite a lot of resistance against this more cataclysmic view?

CT: It is certainly true that a great many people until recently believed that the earth was a closed system, that we didn't have to worry about anything outside the earth. This idea goes back to those people who thought that the earth was the centre of the solar system, and indeed that the solar system was the centre of the Universe, and people wanted to believe that change was by slow, gradual means. They didn't really want to bring in the idea of life affecting it, which brings in another very interesting set of arguments. They liked the idea that the earth is physically close a part, a closed system that doesn't have impacts, which is why there was so much resistance when the Alvarez, father and son, produced the hypothesis that the reason for the demise of the dinosaurs, 65 million year ago, was the impact of an asteroid or comet (nobody knows which), which had this cataclysmic effect. Then they produced the evidence which showed in the end that this had indeed happened, that there was a crater of 180 km in diameter in Mexico, in Yukatan. And gradually, people, after fierce resistance to the idea, have come much more inclined to accept the fact that the earth's history is constantly affected by cataclysmic events. You must remember that in the arguments that took place over Darwin - Darwin believed that evolution was by gradual means, although he always allowed for some abrupt changes - and when people suggested that evolution of life might also be subject to abrupt changes of the kind that could be produced by impacts from outside, I gather there was a lot of resistance. And people like Stephen J Gould, with the idea of what he called 'punctuated equilibrium' - the equilibrium being the steady evolution, the punctuation being some event from outside or an event which disrupts the normal course of development, all this also produced resistance.

JK: Did you encounter this remnants of resistance in your talks, in your negotiations and discussions with scientists and politicians?

CT: No. I find that the most interesting reflection on the whole from politicians an from others is not that.  It is ... well, alright, you are right, there have been many of these cataclystic impacts in the past but what on earth can we do about it?  Wouldn't it be better to worry about the price of bread or the distribution of wealth in the world, or the current problems that vex mankind, rather than worry about something that is very remote and if it ever happens would be quite uncontrollable and quite unmanageable in any way.

JK: What is your answer?

My answer is: some of the really big stuff might indeed be that, be uncontrollable, but that, for the first time ever in the history of life, one particular animal species has got it within its power, at least theoretically in its power, to deflect catastrophes of this kind. And it would be gross irresponsibility if we would not look into it. And above all, that we should need to know much more about what the threat really was and consider what could be done. For example, you could find that it is a problem, in a sense, of civil defence. Supposing there is an object going to hit Britain or Germany, there would be a major question of what should the local defence authorities do. Should you try to get people away from the coast where you might have the risk of huge waves, washing people away, or what should you do? And so it would be a problem of civil defence.  There is also the problem of saying: well, we can see the problem of 10 years from now a comet or a fragment of a comet is likely to hit the earth. Can we put our heeds together and do something which might deflect it, in which case it would be very irresponsible of us not to try and do so. This was mode a theme, of course, in the film Deep Impact', which greatly affected the public mind about it, and Armageddon as well.

JK: Before we come to the question of what can be done, what are the technologies available if there are any...- another question regarding the reaction of the scientific community and the wider public: You could argue that we had very severe cataclysms, most probably caused or definitely caused by the impact with comets or asteroids, but the argument goes: now, for the last few millions years, it has been quiet, this was in a different period in the history of our planet, and it is so unlikely. Or is this opinion wrong, have we been more or less in a state of amnesia and didn't we really take into account that catastrophes caused by the collision with heavenly bodies might have happened in historical times. For instance some astronomers suggest that the Dark Ages were triggered by cosmic bombardment.

CT: Right.  Well, in the early history of the universe there were certainly many more impacts than there are today, that seems to be fairly clear.  You could see the results of impacts on the moon. The latest observations from the asteroids that have had close pictures taken of them show that they are absolutely pitted and covered with impacts. So we know that in the early history of the universe there were a lot of them. Since then, there has probably been a diminution in the number of impacts, but we know nothing to suggest that the impact rate has diminished in the last million years, Indeed, now that we are finding out a lot more about it we can discover what the impact rates are likely to be. In the case of the earth, the forces of wind and weather and erosion tend to eliminate, tend to cover up the effects of impacts but there is one crater, for example in Germany, which is very important; one in Chesapeake Bay where the city of Washington is now built, there was a crater. There are very large craters in Africa and Australia. So wherever you look, you will probably find more craters, but nature has covered them up for us. In the last few years, people have been trying to look for periodicities. It is certainly true that every year there are certain astronomical events, like the arrival of certain meteors, the Leonids and other examples, which are periodical.  But the efforts a number of people have made to show that we come under heavy risks every 28, 29 million years have not actually so far proved their case.  There are periods where you get more of those sort of thing happening but there are also periods where things don't happen very much.  There is nothing to suggest a regular rhythm that we have been able yet to determine. The current situation is that there is a constant movement, a constant bombardment of the earth from outer space, mostly very small things that most people don't notice, some microscopic dust, but this has continued and, little doubt, it will continue.

JK: But there are a lot of near earth asteroids or near earth objects in the inner solar system which might be potential collision candidates. The first task is to find out how many are there, where are they end and are their orbits a potential danger for earth.

CT: Well, as far as we know, and I must underline that I am not an astronomer, we know of nothing at the moment which is on a collision course with the earth. But our ignorance is so great that we can't really be certain about it. The Americans have done a lot of work on objects of more then 1km in size, in diameter, so we don't think that any objects of 1 km or above are about to hit the earth. But, after all, some of the other ones can cause very bad impacts. They might not destroy civilisations but they can certainly make a very nasty hole in the earth. And if you look at the crater in Arizona which was produced about 49,000 years ago, that had a diameter of about 60 m. A lot depends on what the asteroid is made of: is it made of rubble, is it rock, is it hollow, which is the case in perhaps one or two of them, there are hallow elements, or is it metal? What is likely to happen in each case is very different because of the asteroid.  So, by and large, we don't know of any regular periodicities. Calculations have been done to show that objects of 50, 60 m in diameter are likely in a time span of a hundred years, but the big stuff, that is to say more than one km, is more likely in 100 000 years or in millions of years.  We don't know.

JK: First we have to know that they are there and how many of these 1 km in diameter or more are in the solar system.

CT: We know roughly, but we don't know with any great precision. And, of course, observation are nearly all taking place in the northern hemisphere rather than the southern hemisphere which limits the field.

JK: Will this gap be closed?

CT: We would like to do so. One of the things we have been thinking about is the way you get better observations from the southern hemisphere but then some of the new telescopes being set up in Chile will be able to resolve that problem.

JK: What about possible defence mechanisms?  To be able to deflect, to destroy...

CT: Well, that is a huge area of technology in which certainly I cannot claim to be an expert.  There are those who would say that you have to let off a nuclear device in order to deflect it, so that you wouldn't try to destroy it. Because destroying it could mean that the object would remain in its orbit and it would merely mean that instead of one impact you have 50 - as happened in the case of Shoemaker-Levy 9 on Jupiter. The other possibility is that you should try and deflect it, and there have been a number of suggestions. There have been those who suggest that you should make a big nuclear explosion in space, and thereby creating a blast which pushes it out of orbit, depending on the size and the character of the object.  If you didn't get it right, you might break it into fragments which might make things worse rather than better. And there are those who believe that you create something like a limpet, that you attach to the object and power it by solar energy, and provided that it was far enough away, you could gradually nudge it nut of orbit into another orbit,  that would pass by the earth. And there are people who are very suspicious, who say ha, ha, but perhaps you would nudge an object which was coming towards Berlin and nugde it into a direction which lead it perhaps towards Moscow or Bejing. So it is very difficult. I think that is real fantasy. So we looked into all these different things, and obviously a task force in 6 months can't come up with technical answers. And I must underline that nearly all the serious practical work on this subject has been done in the US.

JK: You went to the US, what did they tell you in the Pentagon, for instance?

CT: One, I was very impressed by the degree of information that they put together. I was also impressed by their frankness in admitting that this knowledge was incomplete. Our conversations were, of course, strictly private. But the question of an object arriving from outer space was quite close to the idea of an object arriving from a hostile country, and that way you are getting into what might be described as the star wars area quite quickly. And the Americans have done a lot of work look into these questions. I had the privilege of also going to the observatory at Cape Peak and actually looking at some asteroids through their telescopes which was very interesting because you can actually see them moving around. (They are asteroids going peaceably about their business in the asteroid belt which lies between Mars and Jupiter). So, the Americans have done an impressive amount of work but, so far, they have not created a kind of co-ordinating mechanism. Indeed, one of the interesting things is that no country in the world has yet tried to co-ordinate its research and its civil defence and possible deflection abilities into anything like a single organisation. So we have been thinking about what we ought to do to look at the international level, the European level, because the Europeans might have a lot to contribute, the national level and what kind of institutions might be right for each case.

JK: You mentioned all these different suggestions to deflect or destroy or defend against. Wouldn't star ware be a useful tool? I mean star wars, originally planned as a safety system against hostile missiles, could be turned around?

CT: Exactly, I agree with that.

JK: And are there any movements in this direction?

CT: Not that I know of. Maybe there is something and I haven't heard about it, but I haven't heard that it is going to be used, although it is obviously very relevant. What I think is interesting is that the fact of our task force being set up has caused a lot of people to think again about it. I won't say that the task force is going to produce a report that will shake the world, but the mere existence of a task force to lock into the subject has certainly had some effects of the European Space Agency. They are thinking about things more than they would have done otherwise. And I was told by our American friends that the fact that we have sat up this task force and the kind of people appointed to it had the effect that their community also began to think about it again.  So at least we had a catalystic effect.

JK: And did you get a response from all the other governments, did the European Union for instance react or did they...

CT: Not yet, as far as I know. Well, with the European Space Agency, there has been a lot of interest, and we talked to people there and we talked to people at the European Space Observatory, the one that is going ahead in Chile. And we have talked, of course, to the International Astronomical Union which is the international body which looks at these things. So maybe the appointment of a task force and the kind of work we are doing, however general, does have a sort of catalystic effect in making people feel they need to think about it and maybe also encourage them to think about how research may be better co-ordinated in the future.

JK: Do you cover in your task force discussions in the delicate field Of who should be informed about an approaching near earth object which might hit the earth, or definitely hit the earth?

CT: Well in our terms of reference there is a point about communication with the public which, of course, raises a very difficult question. First, I think it is much better always to be open on these questions, not least because if you aren't open, you are soon found out. Supposing some astronomers found something heading for the earth - do you think that they would be willing - supposing that they have clearer view - do you think that they would be willing to keep the thing quiet?  The answer is that human nature is such that those people who made a major discovery would not wish to sit on it, they would let it be known, somebody would leak it sooner or later. And so the possibilities of withholding information of this kind seems to me to be a complete fantasy. So the question is: can you create a public co-ordinating body which will give measured advice to which journalists will turn when they want to know something. And that, I think, is the answer: you have got to be open, you can't - even if you wanted to - keep things quiet.  So what you have to do is to make sure you have a measured and sensible response, you have to steer a course between creating alarm or creating complacency. This problem is real although it is unlikely to affect any individual very seriously in the world today. It is a very real problem, and somehow you have got to strike that balance.

JK: In a way it is an attempt, for the first time, to look far beyond the limits of one or two generations. It might be a problem in 100 or 200 or 1000 years.

CT: It could be a problem in 100 or 1000 or 200 years, whatever you like. It might also be a Problem tomorrow morning. And that gives it rather a different aspect. The biggest present analogy is with climate change. In the case of climate change you have got international institutions set up to try to measure the effects and to measure the impacts. And the evidence can accumulate, climate change is already taking place. You can try and make judgements about it and consider what should he don about it, because this knowledge is accumulative, it is there all the time. In this event you are faced with an entirely new situation in which something could happen very quickly and very disastrously, or it might need 20 years, 100 years, or a thousand years. So you have got a very difficult balance to make. What is interesting there is that the amount of knowledge that we need to acquire is so great that we may as well get on with it straight away, even if the knowledge of what we would do about it, is bound to leg behind.

JK: You just used the comparison with climate change and the international response. Would you not say that the international response with climate change is disappointingly falling behind in what it should be?  If we draw a parallel from here to there, nothing really might be done in terms of defence systems against Collisions.

CT: Well, I am a realist, and in the case of climate change - a subject which I have been involved with for a very long time, indeed I wrote a book about it in the 1970's, you have an accumulating public knowledge of the subject, a series of world climate, two world climate conferences, people understanding much better what is going on, a series of international commissions set up, and now you have the framework agreement on climate change of 1992, you have frequent meetings of the parties, all that. You cab say they haven't. done very much about it so far, that is true, they have not done a great deal. But I think the momentum is now there, and when they meet later this year to consider which steps should be taken, you will find that there is an accumulating public concern and that people can begin to see. And besides, if climate change starts to have catastrophic effects, then people will begin to say, what are you going to do about it? So nature is on your side, demonstrating that climate change is taking place.  Just look at the last 2 or 3 years, one of the predictions has been more extreme events. There have been extreme events, and what I was hearing from the Chinese about the extraordinary dust storms that have been covering Northern China, as well as the flooding in Mozambique as well as the flooding in Venezuela - all these things are happening. And so, public understanding of the hazards of climate change is going to increase as the drama unfolds. This is not the case with near earth objects, something disastrous may happen in a year, something disastrous may not happen for a thousand years.

JK: The German-Jewish philosopher Hans Jonas, in his address to the Frankfurter Friedenspreis, raised the question of 'how much catastrophe mankind needs to endure in order to change'.  He was referring, of course, to climate change and so on. But if he is right, and the answer is: a lot, people don't act without the experience of catastrophe, then, of course, it makes life even more difficult for advocates of a defence system against cosmic collisions.

CT: It does. But you just have to face this. I think catastrophes on the whole have rather a fruitful effect in human history, because people will not do anything until they see the need to do something. You need, in a way, a combination of 3 things: you need people to give leadership, you must respond to pressure from below when citizens put the heat on politicians to get on with something. And, sometimes, politicians are very reluctant to do so because they are driven by vested interest. But you find that people just feel strongly, and I think, for example, the problems of transport policy in Europe and especially in Britain are now forcing politician to think differently. And then you have catastrophes, and all one can hope is that the catastrophe isn't too big and awful, and that, preferably, it shouldn't affect you.

JK: Let me finally ask you: When You discussed this new task force with your Prime Minister, did he strike you as a Politician who is responsive to issues like that?

CT: I think the Prime Minister is very conscious of a whole variety of threats to stability. This is a subject which is clearly somewhat exotic because it hasn't been talked about at that level, it has been talk about by astronomers. It is rather in the position of climate change, as we have discussed, but I wrote my little book in 1975 -  it is something which few people think about. Well, I think that the issue of near earth objects has yet to arrive at the political level, it is somewhere far below the political level at the moment. And one of the purposes of the task force is to alert people, even people who don't understand astronomy, or are not even interested in astronomy to grasp what the issues really are.

------------- * Sir Crispin Tickell is a member of the UK Task Force on Near Earth Objects. For many years, he was one of Britain's top diplomats, serving, among other placements, as the UK ambassador to the United Nations. He is the chairman of the Royal Geographical Society and is Chancellor of the University of Canterbury.

* Jurgen Kronig is the UK correspondent for the German weekly DIE ZEIT and a freelance author for various publications and TV in Germany, Switzerland and Britain