Long-Living Meteoroids Formed during Radial Expansion of Large Meteoroids

This paper considers a possible mechanism for the formation of long-lived meteoric trails of an unusual geometric shape within the framework of the model of instantaneous destruction of a meteoric body under the action of aerodynamic force and spreading of meteoric matter in the direction transverse to the main motion of the core first proposed in 1979 by S.S. Grigoryan and developed in subsequent years by other authors. In the event under consideration, the long-lived meteor trail was determined by the shape of the meteoroid and its dynamics during the destruction of the meteoroid. The meteor wake began to form near the surface of the meteoroid body during its radial expansion, which is consistent with the model of S.S. Grigoryan instantaneous destruction of a meteoric body under the action of aerodynamic force and transverse expansion when a meteoric body is destroyed by elastic waves. The meteoric trail “forks” in the opposite and radial directions with respect to the flight path of the main meteoroid body. It is noted that the observed lifetimes of long-lived meteor trails (~20–40 min) and their spatial scales (tens to hundreds of kilometers) can be provided by the propagation of large meteoric particles (≥100 μm). These particles have high momentum values, which are preserved during horizontal propagation at atmospheric altitudes with the same density at large distances without a significant loss of velocity. In this case, the glow of the meteor trail can be determined by the classical mechanisms of the intrinsic glow of the meteoric matter and the gaseous components of the atmosphere.