A particle-based model for ablation and wake formation in faint meteors

• Published in: Monthly notices of the Royal Astronomical Society Vol. 447; no. 2; pp. 1580 - 1597
• Main Authors: Stokan, E., Campbell-Brown, M. D.
• Format: Journal Article
• Language: English
• Published: London Oxford University Press 21.02.2015
• Subjects: Ablation; Astrophysics; Computational fluid dynamics; Computer simulation; Deceleration; Dispersion; Evaporation; Light; Meteoroids; Meteors; Meteors & meteorites; Optics; Simulation; Star & galaxy formation; Wakes; methods: numerical; meteorites, meteors, meteoroids
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stu2552

We present a model for the ablation of small, non-fragmenting meteoroids (m < 10−4 kg) at heights in the Earth's atmosphere where the free molecular flow regime is applicable (h > 100 km). The goal of this model is to explain the dimensions of faint meteor wakes observed in our previous high-resolution optical study. Collisions between atmospheric molecules, the meteoroid, and evaporated meteoric particles are modelled to simulate wake formation, as well as ablation and deceleration of the meteoroid. The widths of simulated meteor wakes agree with high-resolution observations of nine meteors selected from our previous study. This suggests that the width of the observed meteor wakes is related to the collisional processes of evaporated meteoric particles, rather than lateral dispersion of fragments or other processes. Simulated meteor beginning heights tend to be higher than observed; otherwise, modelled light curves are in general agreement with observations. Conversely, simulated meteoroids consistently experience less deceleration than observed. Simulated meteor wakes also tend to be short compared to observations. These trends suggest that fragmentation is prevalent in the selected meteors and should be investigated in a future iteration of the model.