The terrestrial example: Natural disasters as model for planetary defense planning

Abstract

Imminent threats draw more attention and resources than the less immediate ones and defense against them is based on the assessment of prospective human and economic tolls. This appraisal allows the development of means for eliminating or reducing said tolls and insuring against the remaining risk. A newly recognized class of threats that has become more apparent in the last few decades are those posed by asteroids and comets. Impacts by sizable natural objects are exceedingly rare but are likely more catastrophic than most terrestrial threats. Lack of immediacy makes the parallel methodology to defend against such threats complex and reliant on developing technologies and untested techniques. Does this paradigm require a different discourse to facilitate an improved defense of increasingly integrated global economies and societies? Experience with common natural disasters and risks are examined to elucidate the question and point to options, while gradual development of technological solutions is appraised for its risk and damage reduction value. It is suggested that to defend against short-term warnings – less than a few years – a degree of readiness must be in place in advance of detection of a possible asteroid or comet impactor. Alternate methods of planetary defense technology that could broaden its value but require risk-informed appraisal, such as nuclear explosive devices, are also considered.