Institution(s): 1. Institute of Astronomy, Russian Academy of Sciences
After the Chelyabinsk event, it is evident that not only large asteroids but also ~10 m size bodies pose a substantial hazard to the Earth civilization. Although the number of near-Earth objects has been growing rapidly in this century due to dedicated surveys, there are large uncertainties in the population count, physical properties and dynamical features of small asteroids. In particular, recent studies of bolide events indicate that the number of impactors with diameters of ~10 m may be an order of magnitude higher than estimates based on telescopic surveys. Moreover, there are some indications that dynamical characteristics of large and small near-Earth objects are different. Near-Earth objects evolve frequently to orbits with small perihelion distances. Asteroids may not maintain its physical integrity during this near-Sun period, producing a number of smaller bodies. A substantial fraction of near-Earth objects approach the Earth from the Sun direction. A dedicated space system is the only way for us to be warned about threatening bodies that come from the daytime sky. I will review recent progress in addressing these issues, focusing on new Russian projects.