Measuring the Terminal Heights of Bolides to Understand the Atmospheric Flight of Large Asteroidal Fragments

Abstract

The extent of penetration into the Earth's atmosphere of a meteoroid is defined by the point where its kinetic energy is no longer sufficient to produce luminosity. For most of the cases this is the point where the meteoroid disintegrates in the atmosphere due to ablation process and dynamic pressure during flight. However, some of these bodies have particular physical properties (bigger size, higher bulk strength, etc.) or favorable flight conditions (lower entry velocity or/and a convenient trajectory slope, etc.) that allow them to become a meteorite-dropper and reach the ground. In both cases, we define the end of the luminous path of the trajectory as the terminal height or end height. Thus, the end point shows the amount of deceleration till the final braking. We thus assume that the ability of a fireball to produce meteorites is directly related to its terminal height. Previous studies have discussed the likely relationship between fireball atmospheric flight properties and the terminal height. Most of these studies require the knowledge of a set of properties and physical variables which cannot be determined with sufficient accuracy from ground-based observations. The recently validated dimensionless methodology offers a new approach to this problem. All the unknowns can be reduced to only two parameters which are easily derived from observations. Despite the calculation of the analytic solution of the equations of motion is not trivial, some simplifications are admitted. Here, we describe the best performance range and the errors associated with these simplifications. We discuss how terminal heights depend on two or three variables that are easily retrieved from the recordings, provided at least three trajectory (h, v) points. Additionally, we review the importance of terminal heights, and the way they have been estimated in previous studies: Finally we discuss a new approach for calculating terminal heights.

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

“…Meteors are generated by the interaction of a cosmic body with the Earth's atmosphere. The physical characteristics of the interacting body, as well as the entry angle, determine the magnitude and duration of these phenomena [1032][1033][1034][1035]. Estimates suggest that, on average, meteoroids cumulatively deposit 5 to 300 t of extraterrestrial material every day, mostly into the Earth's atmosphere [1036][1037][1038].…”

The fireball of November 24, 1970, as the most probable source of the Ischgl meteorite

“…Due to the absence of exact information about the fireball's terminal height, estimates were derived using the methodologies outlined in Gritsevich and Popelenskaya (2008), Moreno‐Ibáñez et al. (2015, 2017) and Gritsevich et al. (2016), and an ultimate cut‐off altitude of 24 km was adopted to eliminate fragments that would not have completed their luminous flight by then.…”