Comparison Study for 2D and 3D Simulations of the Tunguska Event with RAGE and CTH

We present a comparison study for computationally modeling the Tunguska Event of 1908, an airburst explosion equivalent to several megatons of TNT that damaged over 2000 square kilometers of Siberian forest. This kind of event poses a significant threat to our planet, since small astronomical objects like the Tunguska meteoroid are extremely difficult to detect until they are very close to Earth, yet they possess the capability to severely damage large populated areas. Here we compare the results of a new, comprehensive set of Tunguska explosion simulations, created with the Los Alamos National Laboratory adaptive mesh refinement (AMR) hydrocode RAGE, to previous models developed at Sandia National Laboratories using the multidimensional AMR shockwave physics code CTH. We model 2D and 3D representations of a spherical, carbonaceous asteroid entering the atmosphere obliquely relative to the horizontal. We explode the object above Earth's surface, at an altitude and energetic velocity consistent with that of the previous work. We discuss the motivation, methodology, and results of these two sets of models and how they compare. This work is an important consideration to assess our parallel multidimensional modeling capabilities using two well-developed hydrocodes, as well as to understand the nature of this kind of airburst explosion in the context of planetary defense and the potential consequences of a similar event occurring in the future. LA-UR-18-26842