Asteroid Impact Risk Assessment: Rationalizing the Threat

Abstract

The asteroid impact hazard is difficult to conceive in the context of everyday human life. Large-scale impact events of global or regional consequences might not happen for generations, but the consequences in the event of an impact can far surpass those of other natural disasters. In this chapter, statistical methods are employed to express the asteroid hazard in terms that are accessible for the human perspective and that allow the hazard to be placed into context with other natural disasters. In addition to the description of the overall hazard situation in statistical terms, the chapter describes the current means of communicating asteroid impact threat levels of discovered asteroids, such as the Torino and Palermo scales, and introduces a new impact threat scale coined the Southampton Asteroid Hazard Scale. Initially, the chapter introduces the asteroid population in terms of its size and which of its portions have been discovered to date. Subsequently, the statistics of impact angle, speed and location, which drive impact consequences, are presented. The size-dependent portions of the asteroid population that are especially hazardous for the human population are identified based on a statistical assessment of the relevant parameter space.