A Caltech Library Service

Hypervelocity Impacts and Magnetization of Small Bodies in the Solar System

Chen, Guangqing and Ahrens, Thomas J. and Hide, Raymond (1995) Hypervelocity Impacts and Magnetization of Small Bodies in the Solar System. Icarus, 115 (1). pp. 86-96. ISSN 0019-1035. doi:10.1006/icar.1995.1080.

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item:


The observed magnetism of asteroids such as Gaspra and Ida (and other small bodies in the solar system including the Moon and meteorites) may have resulted from an impact-induced shock wave producing a thermodynamic state in which iron-nickel alloy, dispersed in a silicate matrix, is driven from the usual low-temperature, low-pressure, α, kaemacite, phase to the paramagnetic, epsilon (hcp), phase. The magnetization was acquired upon rarefaction and reentry into the ferromagnetic, α, structure. The degree of remagnetization depends on the strength of the ambient field, which may have been associated with a Solar-System-wide magnetic field. A transient held induced by the impact event itself may have resulted in a significant, or possibly, even a dominant contribution, as well. The scaling law of Housen et al. (Housen, K. R., R. M. Schmidt, and K. A. Holsapple 1991. Icarus 94, 180-190) for catastrophic asteroid impact disaggregation imposes a constraint on the degree to which small planetary bodies may be magnetized and yet survive fragmentation by the same event. Our modeling results show it is possible that Ida was magnetized when a large impact fractured a 125 +/- 22-km-radius protoasteroid to form the Koronis family. Similarly, we calculate that Gaspra could be a magnetized fragment of a 45 +/- 15 km-radius protoasteroid.

Item Type:Article
Related URLs:
URLURL TypeDescription
Additional Information:© 1995 by Academic Press, Inc. Received October 10, 1994; Revised January 17, 1995. Research supported by NASA. Support for R.H. at Caltech was provided under Sherman Fairchild Distinguished Scholar Program. Suggestions for improving the manuscript proferred by K. Housen and an anonymous reviewer are appreciated. Contribution 5404, Division of Geological and Planetary Sciences.
Funding AgencyGrant Number
Sherman Fairchild FoundationUNSPECIFIED
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences5404
Issue or Number:1
Record Number:CaltechAUTHORS:20141024-123034988
Persistent URL:
Official Citation:Chen, G., Ahrens, T. J., & Hide, R. (1995). Hypervelocity Impacts and Magnetization of Small Bodies in the Solar System. Icarus, 115(1), 86-96. doi:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:50796
Deposited On:24 Oct 2014 20:23
Last Modified:10 Nov 2021 19:00

Repository Staff Only: item control page