The atmospheric breakup of an incoming asteroid and deposition of its energy into both the atmosphere and ground is of great interest to the planetary defense community. The breakup of an incoming asteroid will heat the atmosphere and generate a shockwave and is highly dependent on the asteroid’s size, physical characteristics, and incoming trajectory. In this contribution, we analyze how the...
In the PDC25 scenario at initial assessment, the asteroid may impact nearly vertically over Cape Town or at increasingly shallow angles moving north over Africa and Europe. This presentation will compare the predictions for blast and thermal damage from coupled radiation-hydrocode simulations using the ALE3D hydrocode and the NERO thermal radiation transport code.
For height-of-burst...
Super-bolides are of particular interest to planetary defense since they can release
vast amounts of energy (500 kton to >10 Mton) during atmospheric entry. Superbolides
such as Chelyabinsk (20m, 2013) and Tunguska (50m, 1908) are two
contemporary examples of the effects airburst phenomena have, ranging from minor
structural damage to prominent land devastation. Smaller scale celestial...
Please find attached an extended abstract for PDC2025 (9th IAA Planetary Defense Conference).
I am the corresponding author, and can be reached at:
michael.aftosmis@nasa.gov
Asteroid strikes can cause extensive blast damage to surrounding regions, either by impacting the surface or bursting explosively during entry. The severity and extent of the resulting blast damage areas depend both upon the energy of the airburst/impact and the airburst altitude at which most of that energy is deposited into the primary blast. For a given blast energy, there is an ‘optimal’...
Initial effects of asteroid impact and airbursts include thermal radiation and overpressure blast waves. If sufficiently large asteroid fragments reach the surface, seismic activity or tsunamis may occur if over land or sea, respectively. However, other effects that could extend the geographic areas affected and/or result in long-term physical hazards are less characterized. We categorize...
Keywords: blast, overpressure, Lamb wave, airburst, tsunami
Atmospheric entry and disruption of very large bodies produces blast waves with damage radii reaching hundreds or even thousands of kilometers. Recent 3D computational simulations of large impactors (above roughly 1 Gt kinetic energy at entry) demonstrate that these large blasts initially expand roughly spherically and then...
Meteorite terrestrial impacts are established as the causes of large circular geological structures, major crustal deformations, large volumes of displaced rocks, extensive ejecta, and ultimately non-ideal debris cloud formation. Statistically, these are rare events, and the physical processes involved in terrestrial impacts and their subsequent induced effects, such as cratering, ejecta...