Mercury’s thermoelectric dynamo model revisited
نویسنده
چکیده
We reconsider the thermoelectric dynamo model for the generation of the magnetic /eld of Mercury, as proposed by Stevenson (Earth Planet. Sci. Lett. 82 (1987) 114). We brie4y review the status of our knowledge about the nature of Mercury’s planetary /eld, and describe the main features of the /eld generated through a thermoelectric dynamo, including its multipole expansion. We then discuss the possibility of testing this model, by correlating future measurements of Mercury’s magnetic and gravitational /elds. We conclude that the test is, in principle, very robust, and discuss possible limits on its interpretation. ? 2002 Elsevier Science Ltd. All rights reserved. PACS: 96.30.Dz; 96.35; 95.55.Pe; 91.10.Qm; 91.25.Cw
منابع مشابه
Powering Mercury’s dynamo
[1] The presence of the global magnetic field of Mercury has implications for the interior structure of the planet and its thermal evolution. We use a thermal evolution model to explore the conditions under which excess entropy is available to drive a convective dynamo. The current state of the core is strongly affected by its sulfur concentration and the viscosity of the overlying mantle. A pr...
متن کاملCrustal remanence in an internally magnetized non-uniform shell : a possible source for Mercury’s magnetic ¢eld?
We consider the magnetic field of a shell uniformly magnetized by an internal dipole that is subsequently removed. The Gauss coefficients of the resulting field are given in terms of the spherical harmonic coefficients of the shell thickness. This general solution can easily be reduced to common special cases by superposition. For a shell of constant thickness the external field vanishes (by Ru...
متن کاملLow-altitude magnetic field measurements by MESSENGER reveal Mercury’s ancient crustal field
Magnetized rocks can record the history of the magnetic field of a planet, a key constraint for understanding its evolution. From orbital vector magnetic field measurements of Mercury taken by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft at altitudes below 150 kilometers, we have detected remanent magnetization in Mercury’s crust.We infer a lower boun...
متن کاملMagnetic Field at Mercury: Effects of External Sources on Planetary Dynamos
SOURCES ON PLANETARY DYNAMOS Natalia Gómez Pérez1 and Johannes Wicht2 1Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington DC, 20015 USA ([email protected]) 2Max Planck Institute for Solar System Research, Katlenburg-Lindau, 37191 Germany Introduction: Intrinsic magnetic fields in celestial bodies may be attributed to planetary dynamo processes. On Earth, t...
متن کاملMercury’s sodium exosphere: Magnetospheric ion recycling
[1] A three-dimensional Monte Carlo model of Mercury’s neutral sodium exosphere was used to describe correlation between the observed variations in the exospheric density and the variations in the surface concentration of sodium along Mercury’s motion around the Sun [Leblanc and Johnson, 2003]. Four processes of ejection were taken into account: thermal and photon stimulated desorptions, solar ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2002