Social scientists convened in Irvine California on Friday, April 11,
2002 to discuss human reaction to the possibility that a large
asteroid or comet will collide with Earth, perhaps causing global
devastation. The purpose of this workshop was to consider managing
disasters that are far beyond the scope of local, regional, and
national authorities. Although the papers focused explicitly on the
threats to Earth posed by asteroids and comets, much of the material
was applicable to other low-probability high-consequence events. The
session was a sequel to a technically oriented workshop sponsored by
the American Institute of Aeronautics and Astronautics and held in
Spain in 2001. This earlier conference focused on finding and
intercepting dangerous near earth objects. Participants there
realized that purely technical solutions were not enough, and urged a
follow-up workshop to explore the socio-cultural and psychological
aspects of the threat.

Although we can see the record of impacts on the surface of the Moon
the threat to Earth was not widely appreciated until the latter part
of the 20th century when scientists discovered that asteroid impacts
were the most likely cause of past massive extinctions on Earth
including the extinction of dinosaurs 65 million years ago. We know
that objects hit Earth’s atmosphere all the time; most burn up, but
some make it through to the Earth’s surface. Small objects are common
but do little damage (one literally smashed the trunk of a car).
Large objects are rare, but can do immense damage and very large
objects have the potential of destroying all human life. We can
expect a major local disaster about once every thousand years, a
global disaster about once every million years, and an
extinction-level event about once every hundred million years.

Astronomers have made tremendous progress finding and tracking
potential interlopers in our solar system, and it may be possible to
predict an impact decades or even centuries in advance. We can
develop the technology to destroy or deflect some approaching
objects, but not all threatening objects have been found and there is
a 40 percent chance that a major comet or asteroid would arrive with
very little advance warning. It could be a matter of days before we
realize with any degree of certainty when and where an object will
hit Earth.

Issuing a warning can itself have a profound effect, even if the
prediction turns out not to be true. Who issues the alert, and at
what level of probability that the object will hit Earth? At
present, no governing or advisory body is in a position to oversee

Advance warning would allow time for planners to generate
alternatives, consult, carefully weigh and evaluate new information,
reach decisions, build consensus, and make careful plans for
implementation. On the other hand, substantial warning may place the
event beyond the institution’s planning horizon, and discourage
people from attending to the threat. Ample warning increases the
opportunity for special interest groups to form, generate dissent,
and initiate political action. Advance warning is likely to incur
certain costs such as an economic slowdown, and a lowered quality of
life. Warnings could be counterproductive if they routinely prove to
be false alarms, or if the public does not believe that there are
ways to mitigate the threat. Governments may consider it to their
benefit to create a “spin” that decreases warning costs. Little or no
warning raises prospects of horrendous casualties and the
catastrophic failure of rescue and recovery operations.

Authorities at many different levels including top policy makers,
enforcement agencies such as the military and police, disaster and
relief workers, and residents of affected or at-risk areas will make
decisions with life-death outcomes. Such decision-making could be
viewed as an interactive process that empowers people to take
self-protective steps. Offering the public objective information is
only one small step. Widespread understanding is unlikely if the
information is not geared to people with a sixth grade education.
Cultural and psychological factors will influence how the public
processes the warning and whether or not they then take sensible
action. People understand that there are “official” and “unofficial”
parts of a government announcement, and they will not always listen
to scientists. People who call astronomers for reassurance do not
always accept that reassurance at face value. Furthermore, many
people adhere to religions that predict that the end of the world
will come about as the result of an asteroid strike.

It will be difficult to avoid falling prey to wishful thinking
(including denial, rationalization, and buck-passing) and to panicky,
ineffective decision-making brought about by extreme stress. Other
threats to planning and survival include the “giggle factor” (that
is, ridicule on the part of people who lack foresight and are so
absorbed by the immediate here and now that they are completely
insensitive to unlikely events); sensationalized and rapidly
abandoned dire predictions; supernatural interpretations that direct
attention away from rational searches for survival strategies;
disaster myths; a widespread and growing lack of trust in the US
government; and the misinterpretation of an asteroid impact as an act
of war. Because we have little or no experiential base for planning
for very rare occurrences, planning efforts may lead to “fantasy
documents” that bear little or no correspondence to the actual
unfolding of events.

Casualties will result from the primary effects of the impact and
from “secondary effects” associated with the breakdown of the
infrastructure including transportation and communication systems,
the loss of water and food supplies, and the loss of home and
livelihood. Disasters have ripple effects, spreading out from the
epicenter and affecting ever-larger numbers of people. In essence
there are “circles of victims” beginning with the dead and injured
and expanding to include the bereaved, the disaster workers, and
(through the media) society at large. People who are physically
unscathed may bear profound psychological scars, including
post-traumatic stress disorders. Psychological problems may appear
long after the fact. Overall, minimizing and managing casualties
could be an overwhelming task. Our society may not be able to
maintain the luxury of poring through the rubble, looking for
survivors when there is only the slimmest chance that anyone could
remain alive, and we may have to come up with tough new standards for
managing triage.

Extinction is generally a two-step process, beginning with a
calamitous event that kills the preponderance of members of a species
followed by a series of “local disasters” that “mop up” the
survivors. One way for Homo sapiens to minimize the risk of
extinction is to become a two-planet species. Another possibility is
to create “survival communities” in the form of stout underground
shelters that are able to withstand a large impact and the functional
equivalent of a nuclear winter. Risk is reduced if survival
communities are widely dispersed (so that people who survive the
initial impact will not all succumb to the same localized secondary
catastrophe) and if each community is relatively large (over 500
people each). Establishing underground or orbiting shelters for some
but not all people raises issues of authority, selection criteria,
enforcement procedures, and public acceptance and buy-in.

To some extent plans for establishing permanent communities on the
moon or on Mars can inform our plans for re-establishing ourselves on
Earth following a near extinction-level event. Post-impact recovery
will depend on such factors as population size and growth, rate of
depletion of stored supplies, and the restoration of means of
production. Psychological problems and social conflicts that are kept
under control during the period of “button up” may break loose during
the re-emergence stage. Since they will function in isolation from
one another during the period of isolation and confinement, there may
be some tendency for different communities to become separatist by
the time that they emerge from their shelters. To reduce the risk of
hostility, aggression, and destructive competition among surviving
groups, we might try to imbue a strong overall culture and make sure
that these separated communities remained in constant communication
during the “button up” period.

The workshop concluded with an appeal for additional research. It is
not entirely clear how to plan for unprecedented events. How can we
encourage study and preparation without raising fear? To what extent
can we draw on past experience as we think about the unthinkable? Are
atomic blasts, volcano eruptions, major earthquakes and tsunami
useful analogues? How can we develop warning systems that do more
good than harm? Certainly we cannot devote a substantial portion of
the GNP to protecting ourselves from remote events, so how can we
ensure that the relevant scientific, industrial, medical and
humanitarian organizations can grow quickly at the “moment of truth?”

An Australian astronomer, Ray Norris, notes that a supernova would be
likely to depopulate all planets within 50 light years. A Gamma Ray
Burster is even more formidable, releasing energy on the order of
five magnitudes the order of energy released by a supernova. It can
exterminate life over many thousands of light years. Norris
calculates that supernovas and GRBs should activate Earth’s “reset”
button every 200 million years but as far as Norris can tell this has
not happened for about twenty times that period. Perhaps our luck
will continue to hold, perhaps not.

Harvey Wichman, Director of the Aerospace Psychology Laboratory at
Claremont-McKenna College, and Ivan Bekey, an engineer with the
International Academy of Astronautics and organizer of the technical
workshop held in Spain organized the Irvine Conference. The
Conference was sponsored by the Kravis Leadership Institute, Ron
Reggio Director, and had strong support from the Western
Psychological Association. Speakers included Clark Chapman, Office of
Space Studies, the Southwest Research Institute; Benny Peiser,
Department of Social Anthropology, Liverpool John Moores University
UK; Albert A. Harrison, Department of Psychology, University of
California, Davis; Geoffrey Sommer, Policy studies, RAND Corporation;
Lee Clarke, Department of Sociology, Rutgers University; Douglas
Vakoch, Psychologist, The SETI Institute and Tammy Calvano, now of
New Mexico State.