Planetary Defence and NEO Risks

The Place of the Apophis Asteroid on the Torino, Palermo, and CIRAS Scales

Abstract

The paper introduces evaluation methods for the impact risk of near-Earth objects (NEOs), with a particular focus on the Apophis asteroid—a prime example of the current challenges in planetary defense. The paper explains the workings of the traditional Torino and Palermo scales. Additionally, the Cosmic Impact Risk Assessment Scale (CIRAS) is introduced, which refines risk assessment by integrating seven key factors—energy, impact probability, remaining time until impact, impact location, atmospheric effects, secondary hazards, and mitigation difficulty. The close approach of Apophis in 2029 serves as an exceptional case study. While the initial uncertain orbital data suggested a high risk, the most recent measurements indicate an almost negligible chance of collision. The study emphasizes that the combined use of these scales not only allows for clearer communication of risks but also supports the development of targeted planetary defense strategies. This new approach enables more reliable forecasts, contributing to improved social and technological preparedness as well as the timely detection of potential hazards. Overall, the research underlines the importance of detailed, multidimensional risk assessments that facilitate swift responses and the implementation of preventive measures, thereby ensuring Earth’s safety against potential cosmic threats. This approach opens new horizons in the field of planetary defense.