Impact craters on asteroids: Does gravity or strength control their size?

Michael C. Nolan, Erik Asphaug, H. Jay Melosh, Richard J. Greenberg

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

The formation of kilometer-size craters on asteroids is qualitatively different from the formation of meter-size (laboratory -and weapons-scale) craters on Earth. A numerical hydrocode model is used to examine the outcomes of various-size cratering impacts into spheres and half-spaces. A shock wave fractures the target in advance of the crater excavation flow; thus, for impactors larger than 100 m, impacting at typical asteroid impact velocities, target tensile strength is irrelevant to the impact outcome. This result holds whether the target is initially intact or a "rubble pile," even ignoring the effects of gravity. Because of the shock-induced fracture, crater excavation is controlled by gravity at smaller sizes than would otherwise be predicted. Determining the strength-gravity transition by comparing the physical strength of the material to the force of gravity will not work, because strength is eliminated by the shock wave.

Original languageEnglish (US)
Pages (from-to)359-371
Number of pages13
JournalIcarus
Volume124
Issue number2
DOIs
StatePublished - Dec 1996

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asteroids
craters
asteroid
crater
gravity
gravitation
excavation
shock wave
shock waves
cratering
impactors
impact velocity
weapons
weapon
piles
half space
half spaces
tensile strength
pile
shock

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Impact craters on asteroids : Does gravity or strength control their size? / Nolan, Michael C.; Asphaug, Erik; Melosh, H. Jay; Greenberg, Richard J.

In: Icarus, Vol. 124, No. 2, 12.1996, p. 359-371.

Research output: Contribution to journalArticle

Nolan, Michael C. ; Asphaug, Erik ; Melosh, H. Jay ; Greenberg, Richard J. / Impact craters on asteroids : Does gravity or strength control their size?. In: Icarus. 1996 ; Vol. 124, No. 2. pp. 359-371.
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