Until now two mechanisms of dust generation in the Kuiper Belt have been considered: collisions between objects and their bombardment by interstellar dust. We propose a new mechanism for dust generation at large heliocentric distances associated with cometary outbursts. In this mechanism, dust generation is not related to collisions. Cometary nuclei at large distances from the Sun are exposed to intense irradiation by galactic cosmic rays, which at low temperatures leads to the accumulation of free radicals in the ice. When a critical density is reached, a subsequent explosive recombination of these radicals triggers cometary outburst ejecting dust into the surrounding space. We estimated the number of cometary outbursts and bodies required to sustain the dust flux level observed by the New Horizons mission. The proposed mechanism can explain the high level of dust flux registered by the Venetia Burney Student Dust Counter, which increases with heliocentric distance from 42 to 55 AU, and may contribute to understanding the dynamics of interplanetary dust in the outer Solar System.
Pavlov et al. (2026) studied this question.