Global distribution of crustal magnetization discovered by the mars global surveyor MAG/ER experiment
Vector magnetic field observations of the martian crust were acquired by the Mars Global Surveyor (MGS) magnetic field experiment/electron reflectometer (MAG/ER) during the aerobraking and science phasing orbits, at altitudes between approximately 100 and 200 kilometers. Magnetic field sources of multiple scales, strength, and geometry were observed. There is a correlation between the location of the sources and the ancient cratered terrain of the martian highlands. The absence of crustal magnetism near large impact basins such as Hellas and Argyre implies cessation of internal dynamo action during the early Naochian epoch ( approximately 4 billion years ago). Sources with equivalent magnetic moments as large as 1.3 x 10(17) ampere-meter2 in the Terra Sirenum region contribute to the development of an asymmetrical, time-variable obstacle to solar wind flow around Mars.
Acuna
MH
NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Bartol Research Institute, University of Delaware, Newark, DE 19716, USA. Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA. Centre d'Etude Spatiale des Rayonn.
Connerney
JE
Ness
NF
Lin
RP
Mitchell
D
Carlson
CW
McFadden
J
Anderson
KA
Reme
H
Mazelle
C
Vignes
D
Wasilewski
P
Cloutier
P