NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Questions about Mercury's role in comparative planetary geophysicsProblems which have arisen in formulating a mutually consistent picture of Mercury's evolution are outlined. It appears that one or more of the following widely adopted assumptions are wrong about Mercury: (1) its original composition at least approximately resulted from equilibrium condensation; (2) its magnetic field arises from a still-active dynamo; (3) its thermal evolution should have yielded early core formation followed by cooling and a global contraction approaching 20 km in the planet's radius; (4) Mercury's surface is basaltic and the intercrater plains are of volcanic origin. It is suggested that Mercury's role in comparative planetology be reevaluated in the context of an alternative timescale based on the possibility that Mercury was subjected to a continuing source of cratering projectiles over recent aeons, which have not impacted the other terrestrial planets. Although such vulcanoids have not yet been discovered, the evolution of Mercury's orbit due to secular perturbations could well have led to a prolonged period of sweeping out any intra-Mercurian planetesimals that were originally present. Mercury's surface could be younger than previously believed, which explains why Mercury's core is still molten.
Document ID
19850025548
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Chapman, C. R.
(Planetary Science Inst. Tucson, AZ, United States)
Weidenschilling, S. J.
(Planetary Science Inst. Tucson, AZ, United States)
Davis, D. R.
(Planetary Science Inst. Tucson, AZ, United States)
Greenberg, R.
(Planetary Science Inst. Tucson, AZ, United States)
Leake, M. A.
(Valdosta State College)
Date Acquired
August 12, 2013
Publication Date
January 1, 1985
Publication Information
Publication: Lunar and Planetary Inst. Terrest Planets: Comp. Planetology
Subject Category
Lunar And Planetary Exploration
Accession Number
85N33861
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

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