Observation of a Long‐Lived Optical Meteor Producing Low Mesosphere Irregularity Echo: Trajectory, Fragmentation, and Spectroscopy

Observations of meteoroids and their associated phenomena in the atmosphere provide crucial insights into the composition and structure of their parent bodies, and enhance our understanding of their impact on the near‐Earth space environment. In this study, we present observations of meteor M20221224_183010 by the meteor and ionospheric irregularity observation system at Hainan, China. This meteoroid underwent extensive, multi‐stage fragmentation (with apparent visual debris but without any sharp spikes and flares) between altitudes of 81.0 and 41.1 km, with an entry velocity of 13.23 km/s. The right ascension and declination of the meteor are 16.27° and −6.8°, respectively, being originated possibly from debris of an Apollo asteroid. The meteor is primarily composed of fragile and comet‐like materials, but also contains regions with mechanical strengths comparable to carbonaceous meteorites, presenting significant internal heterogeneity due to variations in fragmentation resistance. The observation of a continuous emission spectrum indicates that the material distribution remained relatively homogeneous with a high content of Na. This meteoroid produced non‐field‐aligned plasma irregularities around 64–60 km altitudes. We surmise that the meteoroid's continuous fragmentation could produce dust particles, which rapidly acquire charge and form Bragg‐scale structures in low mesosphere, manifesting as non‐field‐aligned plasma irregularity backscatter echoes.