scholarly journals PLANETARY MAGNETIC FIELD AND GRAVITY IN THE SOLAR SYSTEM

2017 ◽  
Vol 5 (9) ◽  
pp. 145-151
Author(s):  
Samir A Hamouda ◽  
Eman A. Alsslam Alfadeel ◽  
Mohamed Belhasan Mohamed
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Magnetic Fields ◽  
Difficult Problem ◽  
Planetary Scale ◽  
Scale Models ◽  
Planetary Magnetic Fields ◽  
Solar System Bodies ◽  
Planetary Magnetic Field ◽  
The Universe

Gravity plays a major role in the planetary formation and the development of the solar system. Gravity attraction is the essence of a power that holds and governs the universe; it makes the planets in the solar system revolve around the sun and the moons around their planets. Magnetic fields are also an important phenomenon in the solar system and beyond. Their causes are complex and have a variety of effects on their surroundings; they have become a critical tool for the exploration of solar system bodies. However, the study of the mechanisms of planets formation in the solar system is a difficult problem made more so by the inability to construct planetary-scale models for laboratory study. However, understanding the nature of the matter comprising the Solar System is crucial for understanding the mechanism that generates planetary magnetic fields and planetary gravity. In this study, a brief history about the development of planetary gravity is presented. Some data about the physical properties of planets in the solar system are presented and discussed. However, much work is still needed before the planetary gravity and planetary magnetic field processes are fully understood and full advantage be taken of the implications of both phenomena  observations.

scholarly journals STUDY OF PLANETARY MAGNETIC FIELDS

2017 ◽  
Vol 5 (3) ◽  
pp. 29-44
Author(s):  
Samir Ahmed Hamouda ◽  
Nada Eaz-Alden Emgau ◽  
Rabab Muftah Bohagar ◽  
Aisha Mohammed Eissa
Keyword(s):  
Solar System ◽  
Magnetic Fields ◽  
Geomagnetic Field ◽  
Difficult Problem ◽  
Dynamo Theory ◽  
Planetary Scale ◽  
Planetary Magnetic Fields ◽  
Ultimate Cause ◽  
Solar System Bodies ◽  
Planets And Satellites

Magnetic fields are an important phenomenon in the solar system and beyond. Their causes are complex and have a variety of effects on their surroundings; they have become a critical tool for the exploration of solar system bodies. Magnetic fields play a very important role in the Sun. From sunspots to coronal heating, from solar ares to coronal mass ejections all these apparently diverse phenomena have magnetic fields as their ultimate cause. The study of the terrestrial dynamo is a difficult problem made more so by the inability to construct planetary-scale dynamos for laboratory study. However, understanding the nature of the matter comprising the Solar System is crucial for understanding the mechanism that generates Earth’s geomagnetic field and the magnetic fields of other planets and satellites planetary dynamo models. In this study, in this study, classifications of planets are introduced. Development of planetary magnetism model is discussed. General concepts of the magnetic dynamo theory are introduced. Properties of planetary magnetic fields are presented and Earth crustal magnetic field is briefly discussed.

scholarly journals Planetary Magnetic Fields and Habitability in Super Earths

2018 ◽  
Vol 27 (1) ◽  
pp. 183-231 ◽  
Author(s):  
Pablo Cuartas-Restrepo
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Scaling Laws ◽  
Thermal Evolution ◽  
Solid Core ◽  
Direct Influence ◽  
Physical Processes ◽  
Planetary Magnetic Fields ◽  
Planetary Magnetic Field ◽  
Planetary Dynamos

Abstract This work seeks to summarize some special aspects of a type of exoplanets known as super-Earths (SE), and the direct influence of these aspects in their habitability. Physical processes like the internal thermal evolution and the generation of a protective Planetary Magnetic Field (PMF) are directly related with habitability. Other aspects such as rotation and the formation of a solid core are fundamental when analyzing the possibilities that a SE would have to be habitable. This work analyzes the fundamental theoretical aspects on which the models of thermal evolution and the scaling laws of the planetary dynamos are based. These theoretical aspects allow to develop models of the magnetic evolution of the planets and the role played by the PMF in the protection of the atmosphere and the habitability of the planet.

Equipotential transformation from multipole systems to dipole systems

1987 ◽  
Vol 414 (1847) ◽  
pp. 359-369
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spherical Harmonic ◽  
Magnetic Moments ◽  
Numerical Comparison ◽  
Magnetic Dipoles ◽  
Planetary Magnetic Fields ◽  
Vector Sum ◽  
Planetary Magnetic Field ◽  
Good Agreement

The paper shows that a planetary magnetic field expressed in the conventional form of a spherical harmonic expanson can be completely represented by the vector sum of fields produced by a set of magnetic dipoles with different magnetic moments, tilted from the planetary spin axis and offset from the planetary centre by different amounts. For convenience, the transformation from multipole systems to dipole systems is restricted to that from multipoles up to octupole to five dipoles. The scalar equipotential transformation analytically results in 24 equations; these can be subsequently solved for the 24 adjustable parameters in dipole systems with the predetermined ‘main dipole’. The numerical comparison of the jovian magnetic field between the jovian O 4 and the five-dipole models reveals a very good agreement with the subtle details. It is obvious that this type of transformation would open up the simplest practical way to simulate planetary magnetic fields with the dipole patterns.

scholarly journals The underexplored frontier of ice giant dynamos

2020 ◽  
Vol 378 (2187) ◽  
pp. 20190479 ◽  
Author(s):  
K. M. Soderlund ◽  
S. Stanley
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Giant Planets ◽  
Dynamo Action ◽  
Future Directions ◽  
Planetary Magnetic Fields ◽  
Planetary Dynamos

The Voyager 2 flybys of Uranus and Neptune revealed the first multipolar planetary magnetic fields and highlighted how much we have yet to learn about ice giant planets. In this review, we summarize observations of Uranus’ and Neptune’s magnetic fields and place them in the context of other planetary dynamos. The ingredients for dynamo action in general, and for the ice giants in particular, are discussed, as are the factors thought to control magnetic field strength and morphology. These ideas are then applied to Uranus and Neptune, where we show that no models are yet able to fully explain their observed magnetic fields. We then propose future directions for missions, modelling, experiments and theory necessary to answer outstanding questions about the dynamos of ice giant planets, both within our solar system and beyond. This article is part of a discussion meeting issue ‘Future exploration of ice giant systems’.

Induced Magnetic Fields in Solar System Bodies

2009 ◽  
Vol 152 (1-4) ◽  
pp. 391-421 ◽  
Author(s):  
Joachim Saur ◽  
Fritz M. Neubauer ◽  
Karl-Heinz Glassmeier
Keyword(s):  
Solar System ◽  
Magnetic Fields ◽  
Solar System Bodies

scholarly journals Magnetism in the Early Universe

2018 ◽  
Vol 14 (A30) ◽  
pp. 295-298
Author(s):  
Tina Kahniashvili ◽  
Axel Brandenburg ◽  
Arthur Kosowsky ◽  
Sayan Mandal ◽  
Alberto Roper Pol
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Gravitational Waves ◽  
Early Universe ◽  
Large Scale ◽  
Direct Detection ◽  
Correlation Lengths ◽  
Cosmological Scenario ◽  
Expansion Of The Universe ◽  
The Universe

AbstractBlazar observations point toward the possible presence of magnetic fields over intergalactic scales of the order of up to ∼1 Mpc, with strengths of at least ∼10−16 G. Understanding the origin of these large-scale magnetic fields is a challenge for modern astrophysics. Here we discuss the cosmological scenario, focussing on the following questions: (i) How and when was this magnetic field generated? (ii) How does it evolve during the expansion of the universe? (iii) Are the amplitude and statistical properties of this field such that they can explain the strengths and correlation lengths of observed magnetic fields? We also discuss the possibility of observing primordial turbulence through direct detection of stochastic gravitational waves in the mHz range accessible to LISA.

scholarly journals On the influence of magnetic fields in neutral planetary wakes

2016 ◽  
Vol 12 (S328) ◽  
pp. 192-197
Author(s):  
C. Villarreal D’Angelo ◽  
M. Schneiter ◽  
A. Esquivel
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Radiation Pressure ◽  
Stellar Wind ◽  
Magnetic Moments ◽  
Radiative Processes ◽  
Planetary Magnetic Fields ◽  
Stellar Magnetic Fields

AbstractWe present a 3D magnetohydrodynamic study of the effect that stellar and planetary magnetic fields have on the calculated Lyα absorption during the planetary transit, employing parameters that resemble the exoplanet HD209458b. We assume a dipolar magnetic field for both the star and the planet, and use the Parker solution to initialize the stellar wind. We also consider the radiative processes and the radiation pressure.We use the numerical MHD code Guacho to run several models varying the values of the planetary and stellar magnetic moments within the range reported in the literature.We found that the presence of magnetic fields influences the escaping neutral planetary material spreading the absorption Lyα line for large stellar magnetic fields.

scholarly journals On interactions of static magnetic fields

2019 ◽  
Vol 70 (3) ◽  
pp. 253-255
Author(s):  
Ömer Zor
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Interaction Energy ◽  
Magnetic Charge ◽  
Dirac Monopole ◽  
Static Magnetic Fields ◽  
The Universe

Abstract We investigated the interaction energy of a Gilbertian magnetic charge with each of the “point” magnetic field sources. Finally we extrapolated a Dirac string can only be defined if there is at most one Dirac monopole in the medium. If there is only one Dirac monopole/string in the universe, the probability of detecting it is essential zero, such that Dirac’s monopole would remain just a “theorist’s particle”.

scholarly journals Mathematical foundation of Capon's method for planetary magnetic field analysis

2020 ◽  
Vol 9 (2) ◽  
pp. 471-481
Author(s):  
Simon Toepfer ◽  
Yasuhito Narita ◽  
Daniel Heyner ◽  
Patrick Kolhey ◽  
Uwe Motschmann
Keyword(s):  
Magnetic Field ◽  
Field Studies ◽  
Multipole Expansion ◽  
Minimum Variance ◽  
Field Analysis ◽  
Analysis Tool ◽  
Data Set ◽  
Magnetic Field Analysis ◽  
Planetary Magnetic Fields ◽  
Planetary Magnetic Field

Abstract. Minimum variance distortionless projection, the so-called Capon method, serves as a powerful and robust data analysis tool when working on various kinds of ill-posed inverse problems. The method has not only successfully been applied to multipoint wave and turbulence studies in the context of space plasma physics, but it is also currently being considered as a technique to perform the multipole expansion of planetary magnetic fields from a limited data set, such as Mercury's magnetic field analysis. The practical application and limits of the Capon method are discussed in a rigorous fashion by formulating its linear algebraic derivation in view of planetary magnetic field studies. Furthermore, the optimization of Capon's method by making use of diagonal loading is considered.

scholarly journals Magnetic Field Evolution in Neutron Star Crusts: Beyond the Hall Effect

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 130
Author(s):  
Konstantinos N. Gourgouliatos ◽  
Davide De Grandis ◽  
Andrei Igoshev
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Hall Effect ◽  
Thermal Emission ◽  
Ohmic Dissipation ◽  
Field Evolution ◽  
The Universe ◽  
The Magnetic Field ◽  
Maxwell Stresses

Neutron stars host the strongest magnetic fields that we know of in the Universe. Their magnetic fields are the main means of generating their radiation, either magnetospheric or through the crust. Moreover, the evolution of the magnetic field has been intimately related to explosive events of magnetars, which host strong magnetic fields, and their persistent thermal emission. The evolution of the magnetic field in the crusts of neutron stars has been described within the framework of the Hall effect and Ohmic dissipation. Yet, this description is limited by the fact that the Maxwell stresses exerted on the crusts of strongly magnetised neutron stars may lead to failure and temperature variations. In the former case, a failed crust does not completely fulfil the necessary conditions for the Hall effect. In the latter, the variations of temperature are strongly related to the magnetic field evolution. Finally, sharp gradients of the star’s temperature may activate battery terms and alter the magnetic field structure, especially in weakly magnetised neutron stars. In this review, we discuss the recent progress made on these effects. We argue that these phenomena are likely to provide novel insight into our understanding of neutron stars and their observable properties.

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