CaltechAUTHORS
  A Caltech Library Service

Oblique Impact: A Process for Obtaining Meteorite Samples from Other Planets

O'Keefe, John D. and Ahrens, Thomas J. (1986) Oblique Impact: A Process for Obtaining Meteorite Samples from Other Planets. Science, 234 (4774). pp. 346-349. ISSN 0036-8075. https://resolver.caltech.edu/CaltechAUTHORS:20141031-104852507

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

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20141031-104852507

Abstract

Cratering flow calculations for a series of oblique to normal (10° to 90°) impacts of silicate projectiles onto a silicate halfspace were carried out to determine whether or not the gas produced upon shock-vaporizing both projectile and target material would form a downstream jet that could entrain and propel SNC meteorites from the Martian surface. The difficult constraints that the impact origin hypothesis for SNC meteorites has to satisfy are that these meteorites are lightly to moderately shocked and yet have been accelerated to speeds in excess of the Martian escape velocity (more than 5 kilometers per second). Two-dimensional finite difference calculations were performed that show that at highly probable impact velocities (7.5 kilometers per second), vapor plume jets are produced at oblique impact angles of 25° to 60° and have speeds as great as 20 kilometers per second. These plumes flow nearly parallel to the planetary surface. It is shown that upon impact of projectiles having radii of 0.1 to 1 kilometer, the resulting vapor jets have densities of 0.1 to 1 gram per cubic centimeter. These jets can entrain Martian surface rocks and accelerate them to velocities greater than 5 kilometers per second. This mechanism may launch SNC meteorites to earth.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1126/science.234.4774.346 DOIArticle
http://www.sciencemag.org/content/234/4774/346PublisherArticle
http://www.jstor.org/stable/1697766JSTORArticle
Additional Information:© 1986 American Association for the Advancement of Science. Received 14 March 1986; accepted 11 August 1986. Research supported under NASA grant NSG 7129. We appreciate the assistance of M. Lainhart with the calculations. We are grateful for the helpful comments proffered by G. Wetherill, D. Stevenson, D. Anderson, J. Melosh, B. C. Clark, D. E. Gault, and M. Kovari. Contribution 4137, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125.
Funders:
Funding AgencyGrant Number
NASANSG 7129
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences4137
Issue or Number:4774
Record Number:CaltechAUTHORS:20141031-104852507
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20141031-104852507
Official Citation:Oblique Impact: A Process for Obtaining Meteorite Samples from Other Planets John D. O'Keefe and Thomas J. Ahrens Science, New Series, Vol. 234, No. 4774 (Oct. 17, 1986), pp. 346-349 Published by: American Association for the Advancement of Science Article Stable URL: http://www.jstor.org/stable/1697766
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:51120
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:31 Oct 2014 18:40
Last Modified:03 Oct 2019 07:29

Repository Staff Only: item control page