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 language | English (US) |
|---|---|
| Pages (from-to) | 359-371 |
| Number of pages | 13 |
| Journal | Icarus |
| Volume | 124 |
| Issue number | 2 |
| DOIs | |
| State | Published - Dec 1996 |
| Externally published | Yes |
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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.
In: Icarus, Vol. 124, No. 2, 12.1996, p. 359-371.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Impact craters on asteroids
T2 - Does gravity or strength control their size?
AU - Nolan, Michael C.
AU - Asphaug, Erik
AU - Melosh, H. Jay
AU - Greenberg, Richard
PY - 1996/12
Y1 - 1996/12
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0030529376&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030529376&partnerID=8YFLogxK
U2 - 10.1006/icar.1996.0214
DO - 10.1006/icar.1996.0214
M3 - Article
AN - SCOPUS:0030529376
VL - 124
SP - 359
EP - 371
JO - Icarus
JF - Icarus
SN - 0019-1035
IS - 2
ER -