Physically based alternative to the PE criterion for meteoroids

Abstract

Meteoroids impacting the Earth atmosphere are commonly classified using the PE criterion. This criterion was introduced to support the identification of the fireball type by empirically linking its orbital origin and composition characteristics. Additionally, it is used as an indicator of the meteoroid tensile strength and its ability to penetrate the atmosphere. However, the level of classification accuracy of the PE criterion depends on the ability to constrain the value of the input data, retrieved from the fireball observation, required to derive the PE value. To overcome these uncertainties and achieve a greater classification detail we propose a new formulation using scaling laws and dimensionless variables that groups all the input variables into two parameters that are directly obtained from the fireball observations. These two parameters, α and β, represent the drag and the mass loss rates along the luminous part of the trajectory, respectively, and are linked to the shape, strength, ablation efficiency, mineralogical nature of the projectile, and duration of the fireball. Thus, the new formulation relies on a physical basis. This work shows the mathematical equivalence between the PE criterion and the logarithm of 2αβ under the same PEcriterion assumptions. We demonstrate that log(2αβ) offers a more general formulation which does not require any preliminary constraint on the meteor flight scenario and discuss the suitability of the new formulation for expanding the classification beyond fully disintegrating fireballs to larger impactors including meteorite-dropping fireballs. The reliability of the new formulation is validated using the Prairie Network meteor observations.

Ultra-High-Energy Cosmic Rays: The Intersection of the Cosmic and Energy Frontiers

“…The observations of meteors are valuable as they provide information about the physical properties of the body entering the atmosphere and, on a larger scale, serve as important input data for the situational awareness of nearby space [1041]. The observations are also used to distinguish the meteoroids which fully ablate in the atmosphere from the less frequent events that survive all the way down to the ground and may be subsequently recovered in form of meteorites [1042][1043][1044]. Fireball observations can be also used to infer the individual trajectories of fragments resulting from atmospheric fragmentation.…”

Classification of fireballs: upgrading the PE criterion

“…On the other, the mass loss parameter, β, characterizes the mass loss rate of the meteoroid; it can be expressed as the fraction of the kinetic energy per mass unit of the body that is transferred to the body in the form of heat divided by the effective destruction enthalpy. Since these two parameters comprise all the meteoroid flight variables earlier included in the PE criterion, but avoid artificial assumptions, we have proposed and studied the hypothesis that there should exist a mathematical expression involving these two parameters which offers an improved classification criterion [2]. In this work, we verify this hypothesis.…”

“…Amongst all the suggested flight parameter relationships available in the literature, the one introduced by Ceplecha and McCrosky [1] in the mid 70's became timely and used in many studies as a 'ground truth'. The empirical work of Ceplecha and McCrosky [1] was also mathematically supported by the single body Newtonian formulation that is still widely used to model the meteor trajectory [2]. Moreover, Ceplecha and McCrosky [1] expanded the use of this relationship to elaborate a meteor classification.…”

A Numerical Approach to Study Ablation of Large Bolides: Application to Chelyabinsk

“…Low values of the ablation coefficient indicate that the object is losing a lesser amount of mass compared to that having a higher value of the ablation coefficient. e ablation coefficient is normally represented in units of s 2 km − 2 and can also be expressed through the dimensionless mass loss parameter [44,63] used through the range of meteor physics studies.…”