NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Solar system ice - Amorphous or crystalline?The meteoritic bombardment of icy surfaces is discussed, focusing on the formation of amorphous ice and its thermal, mechanical, and optical properties. A numerical code has been developed for evaluating the ratio of the volume of the melted and vaporized ice target to the volume of the projectile that has impacted the surface and left a crater. However, water will only vaporize with impact speeds over 4 to 6 km/sec, and subsequent condensation into ice below 150 K will produce amorphous ice. A denser form of amorphous ice exists below 10 K, with the transition into a crystalline form occurring above 150 K. Maximum impact velocities have been defined for all major bodies in the solar system, with the finding that crystalline ice will form in the crater while amorphous ice will form on the ejecta. The amount of each is dependent on the ratio of solidified water to condensed water vapor and on the fraction of solid ejecta.
Document ID
19830067591
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Smoluchowski, R.
(Texas, University Austin, TX, United States)
Date Acquired
August 11, 2013
Publication Date
October 14, 1983
Publication Information
Publication: Science
Volume: 222
ISSN: 0036-8075
Subject Category
Lunar And Planetary Exploration
Accession Number
83A48809
Funding Number(s)
CONTRACT_GRANT: NSG-7505
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available