Recent Advances in Bolide Entry Modeling: A Bolide Potpourri

Abstract

In this paper, we will review recent research on numerous aspects of bolide entry into a planetary atmosphere, including such topics as the entry dynamics, energetics, ablation, deceleration, fragmentation, luminosity, mechanical wave generation processes, a total (panchromatic) power budget including differential and integral efficiencies versus time, etc. Fragmentation, triggered by stagnation pressures exceeding the bolide breaking strength, has been subsequently included in either a collective or non-collective wake behavior limit. We have also utilized the differential panchromatic luminous efficiency of ReVelle and Ceplecha (2002) to compute bolide luminosity. In addition we also introduce the concept of the differential and integral acoustic/infrasonic efficiency and generalized it to the case of mechanical wave efficiency including internal atmospheric gravity waves generated during entry. Unlike the other efficiencies which are assumed to be a constant multiple of the luminous efficiency, the acoustic efficiency is calculated independently using a ''first principles'' approach. All of these topics have been pursued using either a homogeneous or a porous meteoroid model with great success. As a direct result, porosity seems to be a rather good possibility for explaining anomalous meteoroid behavior in the atmosphere.

Acoustic analysis of shock production by very high-altitude meteors—I: infrasonic observations, dynamics and luminosity

“…These data were subsequently used to infer atmosphere temperature and horizontal wind structure in the atmosphere. This is equivalent to point source energies of 10 À6 -10 À5 kt, very similar to the recently quoted minimum expected to produce detectable infrasonic signals at the ground by ReVelle (2005) (1 kiloton TNT ¼ 1 kt ¼ 4.185 Â 10 12 J).…”

“…2. Refine from observations and theory the minimum energy needed to produce infrasonic signals at the ground from small-meteor events building on the early estimates of ReVelle (1976) and ReVelle (2005). 3.…”

A meteorite crater on Earth formed on September 15, 2007: The Carancas hypervelocity impact

“…The meteoroid entry for the Carancas has been simulated (Brown et al 2008;BoroviËka and Spurný 2008) by using the model developed by Revelle (2005) and Ceplecha et al (1998). These models include ablation but for the cited works which modelled the Carancas object, fragmentation was explicitly ignored.…”

NEO fireball diversity: energetics-based entry modeling and analysis techniques

“…In previous treatments of entry dynamics (ReVelle 2004), the author has not focused his attention on precise predictions of the bolide's terminal mass. In this work we have provided two estimates of the terminal mass, one based strictly on the standard singlebody theory (with no fragmentation assumed to be present throughout the entry) and a new estimate based upon the self-consistent correction of the mass based upon predicted changes in the mass to area ratio of the bolide during fragmentation.…”

“…

We have examined the behavior of a number of bolides in Earth's atmosphere from the standpoint of recent entry modeling techniques. The entry modeling has been carried out including a triggered progressive fragmentation model (TPFM) which maintains a maximum drag orientation for the fragments in either the collective or a non-collective wake limit during entry (ReVelle 2004). Specifically in this paper, we have proposed a new method of estimating the terminal bolide mass and have compared it against the corresponding single-body mass loss prediction.

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