Modelling the magnetosphere of Mercury

A model magnetosphere for Mercury is presented using an upstream image-dipole and nightside 2-dimensional tail current sheet method. The tail field is represented by an analytical formulation. Magnetic field data from the Mercury 1 encounter by Mariner 10 in March 1974 are used to determine quantitative parameters of the model magnetosphere, using the method of least squares. The magnetopause crossing points directly observed are used to determine the size of the magnetosphere, and the solar wind conditions are used to determine the magnetospheric field at the stagnation point. The model produces a magnetosphere-like region with planetary field lines that are confined in nearly circular cross-sections transverse to the sun-planet line. Results are used to show geometry, field line configuration, and contours of constant field intensity inside the magnetosphere

Magnetic field of Mercury confirmed

A contention that Mercury possesses an intrinsic magnetic field sufficient to deflect the solar wind flow was confirmed by the Mariner 10 experiment. Predictions made as to the locations where characteristic bow shock and magnetopause boundaries may be observed were also confirmed

Observations of Mercury's magnetic field

Magnetic field data obtained by Mariner 10 during the third and final encounter with the planet Mercury on 16 March 1975 were studied. A well developed bow shock and modest magnetosphere, previously observed at first encounter on 29 March 1974, were again observed. In addition, a much stronger magnetic field near closest approach, 400 gamma versus 98 gamma, was observed at an altitude of 327 km and approximately 70 deg north Mercurian latitude. Spherical harmonic analysis of the data provide an estimate of the centered planetary magnetic dipole of 4.7 x 10 to the 22nd power Gauss/cu cm with the axis tilted 12 deg to the rotation axis and in the same sense as Earth's. The interplanetary field was sufficiently different between first and third encounters that in addition to the very large field magnitude observed, it argues strongly against a complex induction process generating the observed planetary field. While a possibility exists that Mercury possesses a remanent field due to magnetization early in its formation, a present day active dynamo seems to be a more likely candidate for its origin

The magnetic field of Mercury, part 1

An updated analysis and interpretation is presented of the magnetic field observations obtained during the Mariner 10 encounter with the planet Mercury. The combination of data relating to position of the detached bow shock wave and magnetopause, and the geometry and magnitude of the magnetic field within the magnetosphere-like region surrounding Mercury, lead to the conclusion that an internal planetary field exists with dipole moment approximately 5.1 x 10 the 22nd power Gauss sq cm. The dipole axis has a polarity sense similar to earth's and is tilted 7 deg from the normal to Mercury's orbital plane. The magnetic field observations reveal a significant distortion of the modest Hermean field (350 Gamma at the equator) by the solar wind flow and the formation of a magnetic tail and neutral sheet which begins close to the planet on the night side. The composite data is not consistent with a complex induction process driven by the solar wind flow

Interaction of solar wind with Mercury and its magnetic field

A brief review is presented of magnetic field and solar wind electron observations by Mariner 10 spacecraft. The intrinsic magnetic field of the planet Mercury and the implications of such a field for the planetary interior are also discussed

Magnetic field observations near Mercury: Preliminary results from Mariner 10

Results are presented from a preliminary analysis of data obtained near Mercury by the NASA/GSFC Magnetic Field Experiment on Mariner 10. A very well developed, detached bow shock wave, which developed as the super-Alfvenic solar wind interacted with the planet Mercury was observed. A magnetosphere-like region, with maximum field strength of 98 gamma at closest approach (704 km altitude) was also observed, and was contained within boundaries similar to the terrestrial magnetopause. The obstacle deflecting the solar wind flow was global in size, but the origin of the enhanced magnetic field was not established. The most plausible explanation, considering the complete body of data, favored the conclusion that Mercury has an intrinsic magnetic field

Viscous-Inviscid Interactions in a Boundary-Layer Flow Induced by a Vortex Array

In this paper we investigate the asymptotic validity of boundary layer theory. For a flow induced by a periodic row of point-vortices, we compare Prandtl's solution to Navier-Stokes solutions at different $Re$ numbers. We show how Prandtl's solution develops a finite time separation singularity. On the other hand Navier-Stokes solution is characterized by the presence of two kinds of viscous-inviscid interactions between the boundary layer and the outer flow. These interactions can be detected by the analysis of the enstrophy and of the pressure gradient on the wall. Moreover we apply the complex singularity tracking method to Prandtl and Navier-Stokes solutions and analyze the previous interactions from a different perspective

Advances in genetics: widening our understanding of prostate cancer

Prostate cancer is a leading cause of cancer-related death in Western men. Our understanding of the genetic alterations associated with disease predisposition, development, progression, and therapy response is rapidly improving, at least in part, owing to the development of next-generation sequencing technologies. Large advances have been made in our understanding of the genetics of prostate cancer through the application of whole-exome sequencing, and this review summarises recent advances in this field and discusses how exome sequencing could be used clinically to promote personalised medicine for prostate cancer patients.</ns4:p