High-Fidelity Blast Wave Modeling of Large Asteroid Impacts

Researchers at the NASA Advanced Supercomputing (NAS) facility at Ames Research Center examined blast wave propagation and Earth’s atmospheric response to entry of the hypothetical asteroid PDC 2023 for the International Academy of Astronautics (IAA) Planetary Defense 2023 conference. The Ames team studied the blast formation from both the hot entry and impact of this large, 800-meter diameter, imaginary asteroid. The entry and impact releases over 10 gigatons of energy into the atmosphere and on the ground near the impact site. In addition to the blast physics, ground footprints of maximum overpressure and wind speed are also captured for this large 3D unsteady simulation. The team also studies the response of Earth’s atmosphere to the blast including the formation of Lamb waves, which can circumnavigate the globe for several days after impact. This work was funded by the NASA Planetary Defense Coordination Office, which manages the agency’s rapidly growing efforts to find possible threatening near-Earth objects, coordinate global planetary defense efforts, and study technologies to mitigate these threats.

Quick Facts

Simulations of asteroid entry have length and time scales that span many orders of magnitude, making them among the most challenging unsteady problems to compute. Supercomputing resources and highly scalable simulation tools are the key to these simulations since they are characterized by extremely fine grids and large numbers of iterations.

• Simulations were done using NASA’s Cart3D simulation code on 16,000 Cascade Lake cores of NASA Ames’ Aitken supercomputer, taking roughly 12 hours to complete.
• One of the key results shows that in addition to the local devastation around the hypothetical impact point, this class of impactor would likely trigger fluctuations in the Earth’s atmosphere that would circle the globe for several days, potentially triggering tsunamis far from the impact point.
• While an impact of this magnitude is extremely unlikely, data from these simulations helps quantify the risk associated with the planetary impact of large asteroids. It also helps researchers understand what simulation tools are needed for accurate prediction and gaps in existing tools.
• This extreme exercise helped highlight weaknesses in the current simulation tool chain, and addressing these issues is among the top priorities for the research team’s near-term work plan.

Researchers

• Michael Aftosmis, NASA Ames Research Center
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• Wade Spurlock, NASA Ames Research Center
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More Information

• NASA Planetary Defense Coordination Office
• NASA Asteroid Threat Assessment
• High-Fidelity Blast Modeling of Impact from Hypothetical Asteroid 2021 PDC
• Parallel Mesh Adaptation for Unsteady Blast Simulations on Cartesian Meshes
• Simulation-Based Height of Burst Map for Asteroid Airburst Damage Prediction