By Barry Shorthouse, Ph.D.
The threat of a cosmic collision is very small but not insignificant. The prospect of a large asteroid impacting the earth is not new nor esoteric. Such a hard-nosed newspaper as the Economist has devoted several of their front covers and editorials to the subject, Congress in 1992 had a committee sitting on the matter and Time has published many pages over the last two years on similar topics. The scientific literature has regularly produced over fifty major papers per year on impacts from space covering such topics such as, the origin of oil, extra terrestrial organic matter, the beginnings of life and the source of all the elements. Over the last decade or so the solar system has been visited by Swift-Tuttle, Haley’s Comet, Shoemaker-Levy, Halle-Bopp and very recently we have had the confirmation of a cosmic bombardment by snow balls.
Twenty years ago a Sean Connery science fiction film gave a good graphical account of the devastation delivered to New York by a relatively small asteroid and the “thrill-a minute” entertainment industry has proliferated the theme with even more dramatic and lurid accounts of cosmic annihilation. However not all of these scenarios are totally devoid of technical merit.
The chances of an individual being killed by a cosmic event, over a 100 year time period has been calculated to be greater than being killed in an airliner crash. However the cost and investment made in both prevention and disaster recovery for each event do not compare. Hundreds of millions are spent on air safety and zero on asteroid collision.
The scale of the disaster is energy dependant. Small, slow moving objects go unnoticed and until recently so did the “cosmic snowballs” which according to Dr. Franklin may amount to 15 million balls per year, about 20 feet in diameter aggregating to 2 billion tons of water per year. The Table shows the impact energy and it’s megaton TNT equivalent for fairly common sized asteroids that inhabit the local cosmos.
Size - kilometers
a. The velocity of 45,000 kph is in the satellite range of velocities and less than twice the escape velocity from Earth. 450,000 kph is ¼ of Halle-Bopp’s velocity.
b. If the limit of detection is 1/1000th of a second of arc then a 0.1 km object is 1.3 x 108 km distant when first seen or about one sun distance away. At 45,000 kph the shortest time of arrival would be about 3,000 hrs or 120 days.
c. The largest fossil fuel power plants are about 3,500 Mw, so that the energy of the smallest and slowest asteroid shown here is equivalent to one years worth of maximum output. |
The devastation is proportional to the energy dissipated regardless of its source. The consequences of a large asteroid strike would far out-weigh a full scale nuclear war (the equivalent of 25 million megatons of nuclear bombs).
A curious fact is that public alarm over an airliner crash is wide spread and lasting. By comparison the probability is lower and the consequences trivial compared with an asteroid collision. Action is demanded. Vast resources are spent on air safety and nothing on cosmic collisions.
Few people show awareness and concern for inevitable cosmic collisions in spite of the pock marked face of the moon. 1908 was a long time ago, and so was the San Francisco earthquake. Some reply to the concern of a cosmic collision with a philosophical approach of “It’s the will of God”, therefore there is nothing we can do about it. Alternatively public soporifics may be dispensed by the authorities as with civil nuclear defense in the 1950’s when and if the risk becomes more apparent. There is the “Dr. Strangelove” approach of creating a safe haven for a select “elite” in the event of a nuclear war, ( Regional Administration Centers), but this would not be for the many and would be a closely held secret by those who would benefit.
As an indication of cost, safety and importance, the British Government reckons it is worth about $1.2m to save a life through increased road safety measures but spends zero on an asteroid impact.
However, we would cater for the survivors, however few, with a Disaster Recovery philosophy and plan. In the near future new technologies may offer means of diverting or even destroying many of the “hits” we could suffer, but some asteroids would get through, therefore we plan. The threat is physical. Therefore the response must be physical.
Response
Detailed prescribed plans for a particular town, on a particular continent are premature but there are some generalities that can shape all plans and which all should be developing. A working hypothesis is that most of the impact energy must be adsorbed by Earth’s environment. The size and velocity of the asteroid gives us the amount of energy involved and hence the effects we can expect.
To decide what has to be done and who will do it requires technical judgements that must be methodical, rational and scientifically based. Unfortunately, there are no recipes or theories that guarantee successful decisions in this or any field but there are methods that shorten the odds in our favor. These methods force us to make comparisons that are justifiable and concentrate on what is real, relevant and important. This avoids talking at cross purposes, endemic in large organizations, and offers courses of action that have a consensus and therefore support. Management decision methods are needed which can select alternatives, the order in which things are done, recognize critical points in a program and most important show where and when resources should be allocated. There are many such tools available but all are based on four basic rules:
a. Determine that which is true, real and relevant.
b. Determine that which is true, real but irrelevant.
c. Determine that which is false, confused, myth, rumor and lies. (We believe that willful deception is rare. In the real world questions are often badly phrased, the answers misunderstood and the information is incomplete. We are inclined to believe in incompetency theories rather than conspiracy theories.)
d. Determine those areas in which important information might exist but where we may be forced to “muddle through”.
In the case of a cosmic collision, action must be pro-active. Action plans, resources and training must be in place before the event, otherwise it is too late.
Scenario
Very recently data has been received from a NASA orbiting station that unequivocally shows that a large asteroid, at least 20 kilometers in diameter and an approach velocity of 450,000 kph, is on a collision course with the Earth. It is expected to arrive late in 2004 (about Thanksgiving) and the predicted devastation will exceed the 1908 Tunguska strike by many orders of magnitude. Some estimates say that it will probably rival that in the Yucatan of about 65 million years ago. Previous studies (report to Congress 1992) and calculations on comets such as Swift Tuttle and Shoemaker -Levy indicated that about 1/4 of the World’s population could perish.
The World’s Governments are panic stricken, security on this is at its tightest and senior officials “in the know” have frozen into inaction. Let us suppose that your organization has decided to produce some plan or answers to safeguard or salvage what it can of its property and personnel and be a viable organization after the impact. At this stage there is no certainty where in the World the asteroid will land. The senior officials in your organization are intelligent laymen, excellent administrators, brilliant lawyers and charismatic salesmen but they only have a rudimentary knowledge of the physical sciences. They will be expected to plan, organize and control in response to the impending calamity, saving what they can of their company and it’s people. A large but not limitless budget has been made available for research, training and resource provision, however the scientific expertise of the government and other pools of talent has been stretched very thin and no such help can be expected from outside your organization.
First Steps
There are two questions that must be addressed; the Command and Control and the Science and Engineering.
Command and control normally exercised must in this case be subordinate to the technical requirements. Engineers and scientists must be on top not on tap. For such a situation as we now face, we have only one chance to get it right. When situations are well defined, outcomes known and the future predictable, then conventional command and control predominates. However we are faced with an unprecedented (in our terms) threat and we are trying to minimize the effect of the disaster.
Foremost must be that the senior echelons of the organization are technically au fait with the science or that they be replaced by those who are. A detailed understanding and education must be given to those who can adsorb it. This could be achieved by special programs on two-way closed circuit TV, a team of special tutors dedicated to one individual, virtual reality, role playing and assimilation. All decisions are based on value judgements and those values are derived from experience and knowledge. In educating (not training or informing), those in command and control, the full implication of the science involved must become second nature.
For instance:
•Multiple collisions as with Shoemaker-Levy will greatly increase the impact area, alter the rate of dissipation of energy and the timing of events. An immediate consequence is that all communication and logistic systems must be duplicated in numbers and kind, and be robust and resilient.
•Duplication of skills and personnel to cope with the aftermath. It is not unreasonable to expect 75% attrition of our staff and resources in the first few hours.
•The immediate effects (24hrs) will be electromagnetic black out, tsunamis, large scale earth quakes, even in previously stable areas and triggered volcanoes. These physical events will be massive and random. Predicted “safe” areas should be acquired and prepared.
•The mid term (10 - 20 days) would show wide spread disease, pestilence, a breakdown in order, civil strife, and a failure or annihilation of normal institutions, from power plants, to hospitals, to telephones, water, sewage, and practically any service we normally take for granted. Chronic shortages of food, water and shelter are inevitable.
•The long term (1 - 20 months) problems are to be able to “cope” with “The Nuclear Winter” as described by Carl Sagan and others.
However simple survival is the order of the day. If we survive the first year then mankind stands a sporting chance.
After any large scale disaster the established tenants of politics, religion and philosophy are likely to be challenged and the change enormous. As an example, after the “Black Death” the whole social paradigm in Europe changed for ever, ending feudalism and heralded the mobility of labour and free market economies. The probability in the long term is that a similar social upheaval will occur and as that stage approaches, maybe our organization would wish to recall the old guard.
The engineering and scientific program is much larger undertaking but ironically far simpler. The threat and consequences can be assimilated by computer, experiments performed, scenarios dissected, models and plans made. The engineering outcomes can be quantified, tested and proven. On a much smaller scale, the Manhattan Project, the Polaris Program and NASA’s Moon Shot are examples of what can be done under times of stress and urgency when technology calls the shots.
In mounting a defense against a cosmic collision there must be a will to commit resources and people. Such a decision, as with Kennedy and the moon shot, is brave and maybe unpopular political decision, akin to buying insurance for unknown events. What can be said for this grand, dramatic and Earth shattering event can be scaled down to mundane everyday problems of security, prevention and recovery: problems we all face. All the factors are present in the immediate and small scale problems, except for the urgency, magnitude and inevitability presented by the scenario. Perhaps if the asteroid had hit San Francisco and the earthquake struck Tanguska, then the threat from space would seem more cogent.