Abstract It is shown that a hydrodynamic mechanism of fine aerosol formation is possible as a result of quasicontinuous tearing-off of particles from the liquid fusion film of meteoroid or spacecraft in the high atmosphere. The tearing-off process occurs due to hydrodynamic instability of the film (of Kelvin-Helmholtz or Rayleigh-Taylor type) as it interacts with a high-speed air stream. Two special cases, particle ablation from the front of the meteoroid, and from its side, are considered in detail. A theoretical analysis for determining the criteria for the formation of particles is presented and evaluations for particles and periods of their tearing-off are obtained. The predictions are compared with representative experimental data.