On a Two-Zone Approach to Solving the Problem of Detecting NEAs

In the current formulation of the asteroid and comet hazard (ACH) problem, it is considered necessary to detect a sufficiently large number (more than 90% of the total amount) of hazardous bodies that can collide with our planet. A vast majority of these bodies are near-Earth asteroids (NEAs). Based on the analysis of statistical characteristics of the NEA population, it has been shown that, on a practically significant time scale (~1000 years), the main danger is posed by NEAs of size 10–50 m, since they collide with the Earth more often than larger bodies. Consequently, the main practically significant task of counteracting the ACH is to detect such decameter-sized NEAs. They can can only be detected in close proximity, at distances of less than 0.05 AU from the Earth. The detection timescale is short, measured in hours (up to one day). This problem is still far from being solved. Larger bodies can be detected with more success. They can be detected at greater distances and, accordingly, the detection timescale is much longer. A rational approach to detecting NEAs has been proposed, the essence of which is that it is necessary to accelerate the development of instruments and methods to detect NEAs in the near zone. This is the most immediate challenge. At the same time, it is also necessary to continue work on searching for larger bodies in the far zone. These detection strategies require different technical means.