Animation of a high altitude meteor based on Monte Carlo modeling (AVI, 8.1Mb)
High altitude meteors are meteors that become luminous at
altitudes above ~130 km, where the standard ablation theory of
meteor light production is not applicable. The physical mechanism
responsible for their glow was a mystery. I developed a model that
explained their existence,
morphology and light-curves (Vinkovic 2007, Advances in
Space Research, 39, 574).
The model is based on particles ejected
from the meteoroid surface through the sputtering process. The
kinetic energy of such a sputtered particle is typically more than
1,000 times larger than the energy of particles in the surrounding
atmosphere. Therefore, the sputtered particle creates a cascade of
collisions in the atmosphere during thermalization. I showed
analytically that this process is capable of producing enough light
for detection. In addition, I modeled them with a Monte Carlo code
that I developed specifically for this phenomenon. Theoretical
images reproduced the observed shapes and sizes of high altitude
meteors. I am currently introducing the physics of oxygen excitation
into the code in order to reproduce spectral signatures of those
meteors.
Vinkovic D. 2007, Advances in Space Research, 39, 574 (ADS, PDF)
Theoretical images of a high altitude meteor.
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