Disruption of kilometre-sized asteroids by energetic collisions

E. Asphaug, S. J. Ostro, R. S. Hudson, D. J. Scheeres, W. Benz

Research output: Contribution to journalArticle

135 Citations (Scopus)

Abstract

Recent numerical studies suggest that 'rubble-pile' asteroids (gravitationally bound aggregates of collisional debris) are common in the Solar System, and that self-gravitation may equal or exceed material cohesion for planetary bodies as small as several hundred metres. Because analytical scaling relations for impact cratering and disruption do not extend to this size regime, where gravity and material strength are both important, detailed simulations are needed to predict how small asteroids evolve through impact, and also to ascertain whether powerful explosions offer a viable defence against bodies headed for a collision with Earth. Here we present simulations, using a smooth-particle hydrodynamics code, of energetic impacts into small planetary bodies with internal structure ranging from solid rock to porous aggregate. We find that the outcome of a collision is very sensitive to the configuration of pre-existing fractures and voids in the target. A porous asteroid (or one with deep regolith) damps the propagation of the shock wave from the impactor, sheltering the most distant regions, while greatly enhancing the local deposition of energy. Multiple-component asteroids (such as contact binaries) are also protected, because the shock wave cannot traverse the discontinuity between the components. We conclude that the first impact to significantly fragment an asteroid may determine its subsequent collisional evolution, and that internal structure will greatly influence attempts to disrupt or deflect an asteroid or comet headed towards Earth.

Original languageEnglish (US)
Pages (from-to)437-440
Number of pages4
JournalNature
Volume393
Issue number6684
DOIs
StatePublished - Jun 4 1998
Externally publishedYes

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asteroids
collisions
shock waves
gravitation
cratering
impactors
regolith
cohesion
piles
comets
debris
solar system
explosions
voids
discontinuity
simulation
hydrodynamics
fragments
mechanical properties
rocks

ASJC Scopus subject areas

  • General

Cite this

Asphaug, E., Ostro, S. J., Hudson, R. S., Scheeres, D. J., & Benz, W. (1998). Disruption of kilometre-sized asteroids by energetic collisions. Nature, 393(6684), 437-440. https://doi.org/10.1038/30911

Disruption of kilometre-sized asteroids by energetic collisions. / Asphaug, E.; Ostro, S. J.; Hudson, R. S.; Scheeres, D. J.; Benz, W.

In: Nature, Vol. 393, No. 6684, 04.06.1998, p. 437-440.

Research output: Contribution to journalArticle

Asphaug, E, Ostro, SJ, Hudson, RS, Scheeres, DJ & Benz, W 1998, 'Disruption of kilometre-sized asteroids by energetic collisions', Nature, vol. 393, no. 6684, pp. 437-440. https://doi.org/10.1038/30911
Asphaug E, Ostro SJ, Hudson RS, Scheeres DJ, Benz W. Disruption of kilometre-sized asteroids by energetic collisions. Nature. 1998 Jun 4;393(6684):437-440. https://doi.org/10.1038/30911
Asphaug, E. ; Ostro, S. J. ; Hudson, R. S. ; Scheeres, D. J. ; Benz, W. / Disruption of kilometre-sized asteroids by energetic collisions. In: Nature. 1998 ; Vol. 393, No. 6684. pp. 437-440.
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