The last two decades have recorded a huge increase in interest for all Near Earth Object related issues, not only from the astronomical community but also from institutions such as space agencies and the aerospace industry. This has greatly contributed to rising NEO discoveries to the present rate of about two thousand objects per year, to the monitoring of impact possibilities in the next century on a regular basis and to the development of impact mitigation strategies either in space or on the ground. A number of space missions either past, under study or in the realization phase, exhibit individual asteroids as main targets.
Undoubtedly, an important driving factor has been a growing perception of the impact risk associated to the NEO population: actions are being taken at an international level in order to coordinate the research and engineering efforts in the field of mitigation measures. On the other hand, the scientific relevance of NEOs bear strong interrelations with their hazard, thus involving the astronomical community as a whole. Just to mention a few examples:
- our understanding and modelling of the dynamics of bodies in the near-Earth space has greatly improved, leading to push reliable impact monitoring predictions farther in the future;
- the advancements in our knowledge of the physical characteristics of NEOs has proven to be essential not only to address fundamental issues on the origin and evolution of the small bodies of the Solar System but also for planning successful mitigation actions, but also;
- the surveys aimed at discovering and cataloguing NEOs are constantly progressing, allowing to detect fainter objects and ensure a wider sky coverage. Consequently, a huge amount of data is produced every night, which represents a valuable source of information also in other astronomical fields such as those addressing transient phenomena in the sky.
- high-quality recording of the events associated to very small bodies entering the atmosphere and possibly reaching the ground as meteorites, such as fireballs, has entered a new era. Large scale regional networks such as PRISMA in Italy and FRIPON in France have been recently started to monitor meteorite-dropping events, investigate the links to their parent bodies and trace them back to their origin.
Within this framework the Chianti Topics focussed on Near Earth Objects has the purpose of gathering the different communities involved in NEO-related studies and activities for timely discussing the near-future challenges in NEO science and mitigation.