This area will cover relevant news of the threat to the planet from Near Earth Objects (NEOs) including concepts and designs for mitigation. All opinions are those of the author.

16 February 2009

Poster Paper at Upcoming Lunar and Planetary Science Conference on Nuclear Deflection

There is a paper at the upcoming 40th Lunar and Planetary Science Conference (LPSC) on analysis of nuclear deflection options.

40th Lunar and Planetary Science Conference (2009)
Tuesday, March 24, 2009

Title: "Modeling the Dynamic Response of an Asteroid or Comet to a Nuclear Deflection Burst"
Paper Number: [#2314]
Authors: Bradley P. A. Plesko C. S. Weaver R. P. Clement R. R. C. Guzik J. A. Pritchett-Sheats L. A. Huebner W. F.

Short abstract: The most technically feasible method of deflecting a Potentially Hazardous Object is a nuclear stand-off burst. We show results from our initial models that use bursts ranging from 1 to 1000 kt on 100 meter diameter targets of various compositions.

Portions of the long abstract:

There is much popular press about Potentially Hazardous Objects (PHOs) and how to mitigate their threat. The two mitigation options are destruction or deflection of the PHO. Presently, the most technically feasible method of deflection is a nuclear stand-off burst. However, many questions remain as to the response of an asteroid or comet to a nuclear burst. Recent increases in computing power and scientific understanding of the physical properties of asteroids and comets make it possible to numerically simulate the response of these porous and inhomogeneous bodies to strong shocks and radiation. Here we use the radiation-hydrocode RAGE to explore the coupling of the energy from a nuclear burst to a simplified PHO. We start with simple 1-D and 2-D models of material responses to variations in device yield, along the with composition and porosity of the PHO.

The NASA 2007 white paper “Near-Earth Object Survey and Deflection Analysis of Alternatives” [1] affirms deflection as the safest and most effective means of PHO impact prevention. It also calls for further studies of object deflection. In principle, deflection of a PHO may be accomplished using kinetic impactors, chemical explosives, gravity tractors, or nuclear munitions. Of these, nuclear munitions are by far the most efficient in terms of yield per unit mass launched and are technically mature. However, there are still significant questions about the response of a comet or asteroid to a nuclear burst. Previous calculations of deflection by nuclear munitions ([2], [3], [4], [5], and [6]) either do not assume a standoff burst and/or do not account for the substantial porosity or internal composition variations. These properties may substantially affect how a PHO responds to a standoff nuclear burst [7]. Several recent rendezvous and flyby missions to asteroids and comets showed their wide range of structure and composition, allowing us to model them better. In addition, we now have available computer codes that allow us to model the response of a simulated PHO to the energy from a nuclear burst.

Link: Abstract

Link: LPSC Poster Session List

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