Properties, age, and origin of a huge meteor cluster observed over Scandinavia on 30 October 2022

A meteor outburst consisting of at least 22 meteors above the Baltic sea and southern Scandinavia that occurred on 30 October 2022 was recorded using multiple cameras. A bright fireball was followed by fainter meteors over a 10 second period. All the meteors were travelling on parallel trajectories. The goal of this study is to determine the atmospheric trajectories and photometric masses of meteors and to use these data to determine the specifics of the progenitor meteoroid break-up and cluster formation. Double and triple-station observations using video cameras were used for the calculation of the atmospheric trajectories and photometric masses of the meteors. Their relative positions and mass distribution were then used to determine the time and cause of the meteoroid fragmentation. The relative position of the cluster particles in the atmosphere and the distribution of their masses best correspond to the separation of the smaller fragments from the mass-dominant fragment 10.6±1.7 days before the collision with Earth, assuming a meteoroid bulk density of 1000 kg.m^-3. The ejection velocities are in the range 0.16-0.61 m.s^-1. The directions of the ejection velocities are bounded by a cone with an apex angle of 43^∘. The axis of this cone has ecliptic coordinates of l=154^∘ and b=26^∘ and is 66^∘ away from the direction to the Sun. Thermal stresses appear to be the most likely cause of such meteor cluster formation.