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10,500
Pick-up ion dynamics at the structured quasi-perpendicular shock
physics.space-ph
We study the pickup ion dynamics and mechanism of multiple reflection and acceleration at the structured quasi-perpendicular supercritical shock. The motion of the pickup ions in the shock is studied analytically and numerically using the test particle analysis in the model shock front. The analysis shows that slow pic...
physics
10,501
The determination of shock ramp width using the noncoplanar magnetic field component
physics.space-ph
We determine a simple expression for the ramp width of a collisionless fast shock, based upon the relationship between the noncoplanar and main magnetic field components. By comparing this predicted width with that measured during an observation of a shock, the shock velocity can be determined from a single spacecraft....
physics
10,502
A New Pleiades Member at the Lithium Substellar Boundary
physics.space-ph
We present the discovery of an object in the Pleiades open cluster, named Teide 2, with optical and infrared photometry which place it on the cluster sequence slightly below the expected substellar mass limit. We have obtained low- and high-resolution spectra that allow us to determine its spectral type (M6), radial ve...
physics
10,503
UN/ESA Workshops on Basic Space Science: An Update on Their Achievements
physics.space-ph
During the second half of the twentieth century, expensive observatories are being erected at La Silla (Chile), Mauna Kea (Hawai), Las Palmas (Canary Island), and Calar Alto (Spain), to name a view. In 1990, at the beginning of The Decade of Discovery in Astronomy and Astrophysics (Bahcall [2]), the UN/ESA Workshops on...
physics
10,504
Modeling of Liquid Water on CM Meteorite Parent Bodies and Implications for Amino Acid Racemization
physics.space-ph
We have constructed an asteroid model with the intent of tracking the radial and temporal dependence of temperature and composition throughout a 100-km diameter CM-type parent body, with emphasis on constraining the temperature and duration of a liquid water phase. We produce a non-uniform distribution where liquid wat...
physics
10,505
Enhanced Phase Space Diffusion due to Chaos in Relativistic Electron- Whistler Mode Wave Particle Interactions in Planetary Magnetospheres
physics.space-ph
The chaotic interaction between electrons and whistler mode waves has been shown to provide a mechanism for enhanced diffusion in phase space. Pitch angle diffusion is relevant for the scattering of electrons into the loss cones, thus providing a source for auroral precipitating electrons. A single whistler mode wave p...
physics
10,506
3-D extent of the main ionospheric trough--a case study
physics.space-ph
The EISCAT radar system has been used for the first time in a four-beam meridional mode. The FAST satellite and ALIS imaging system is used in conjunction to support the radar data, which was used to identify a main ionospheric trough. With this large latitude coverage the trough was passed in 2.5 hours period. Its 3-d...
physics
10,507
Auroral field-aligned currents by incoherent scatter plasma line observations in the E region
physics.space-ph
The aim of the Swedish-Japanese EISCAT campaign in February 1999 was to measure the ionospheric parameters inside and outside the auroral arcs. The ion line radar experiment was optimised to probe the E-region and lower F-region with as high a speed as possible. Two extra channels were used for the plasma line measurem...
physics
10,508
Enhanced Pitch Angle Diffusion due to Electron-Whistler Interactions during Disturbed Times
physics.space-ph
During periods of increased magnetospheric activity, whistler wave emissions have been observed with increased wave amplitudes. We consider a pitch angle diffusion mechanism that is shown to scale with whistler wave amplitude and hence is 'switched on' during these periods of intense activity. We consider the interac...
physics
10,509
Test of Cosmic Spatial Isotropy for Polarized Electrons Using a Rotatable Torsion Balance
physics.space-ph
To test the cosmic spatial isotropy, we use a rotatable torsion balance carrying a transversely spin-polarized ferrimagnetic Dy_{6}Fe_{23} mass. With a rotation period of one hour, the period of anisotropy signal is reduced from one sidereal day by about 24 times, and hence the 1/f noise is greatly reduced. Our present...
physics
10,510
Rotatable-Torsion-Balance Equivalence Principleexperiment for the Spin-Polarized Hofe_{3}
physics.space-ph
We use a rotatable torsion balance to perform an equivalence principle test on a magnetically shielded spin-polarized body of HoFe_{3}. With a rotation period of one hour, the period of possible signal is reduced from one solar day by 24 times, and hence the 1/f noise is greatly reduced. Our present experimental result...
physics
10,511
Average observed properties of the Earth's quasi-perpendicular and quasi-parallel bow shock
physics.space-ph
We present a statistical analysis of 132 dayside (LT 0700-1700) bow shock crossings of the AMPTE/IRM spacecraft. We perform a superposed epoch analysis of plasma and magnetic field parameters as well as of low frequency magnetic power spectra some minutes upstream and downstream of the bow shock by dividing the events ...
physics
10,512
Particle Propagation Upstream of CIR Shocks
physics.space-ph
The first high solar latitude pass of the Ulysses spacecraft revealed the presence of MeV particle increases up to latitudes above 60 degrees, well outside the CIR belt but associated in time with the regular passage of these plasma interfaces at more equatorial latitudes. The particle increases have been explained var...
physics
10,513
Alfven Wave Generation by means of High Orbital Injection of Barium Cloud in Magnetosphere
physics.space-ph
An analysis of the Alfven wave generation associated with the barium vapor release at altitudes ~ 5.2 Earth's radii (ER) in the magnetosphere is presented. Such injections were executed in G-8 and G-10 experiments of the Combined Radiation and Radiation Effects Satellite (CRRES) mission. It is shown that the generation...
physics
10,514
Preferential Acceleration of Coherent Magnetic Structures and Bursty Bulk Flows in Earth's Magnetotail
physics.space-ph
Observations indicate that the magnetotail convection is turbulent and bi-modal, consisting of fast bursty bulk flows (BBF) and a nearly stagnant background. We demonstrate that this observed phenomenon may be understood in terms of the intermittent interactions, dynamic mergings and preferential accelerations of coher...
physics
10,515
Gravitational Radiation and its Application to Space Travel, principles and required scientific developments
physics.space-ph
Gravitational radiation is an elusive form of radiation predicted by general relativity, it is the subject of intense theoretical and experimental research at the limit of the sensitivity of today's instrumentation. In spite of the fact that no direct evidence of this radiation now exist, observed astrophysical phenome...
physics
10,516
Laboratory Modelling of the Earth Radiation Belt
physics.space-ph
Method of the laboratory modeling of the Earth radiation belt is presented. Method can be used for the estimation of consequences of global energetic and communication projects realizations.
physics
10,517
Updating the Near-Earth Neutral Line Model
physics.space-ph
In the past thirty years the Near-Earth Neutral Line model for substorms has been proven to be correct in its basic assumption, i.e., that a new neutral line is created near the Earth during substorm onset. Yet there have also been numerous changes and additions to this model, which were necessary to give a more comple...
physics
10,518
In Situ Measurements of the Phobos Magnetic Field During the Phobos-2 Mission
physics.space-ph
In this communication, we examine in situ observations of the magnetic field in the vicinity of Phobos on the "Phobos-2" mission and give some analysis of the data during a unique experiment ``Celestial Mechanics,'' which leads to the support of evidence of the Phobos magnetic field. In particular, it is suggested that...
physics
10,519
Charged Grains In Saturn's F-Ring: Interaction With Saturn's Magnetic Field
physics.space-ph
Saturn's dynamic F-Ring still presents a challenge for understanding and explaining the kinematic processes that lead to the changing structure visible in our observations of this ring. This study examines the effect of Saturn's magnetic field on the dynamics of micron-sized grains that may become electrically charged ...
physics
10,520
Gravitoelectrodynamics in Saturn's F Ring: Encounters with Prometheus and Pandora
physics.space-ph
The dynamics of Saturn's F Ring have been a matter of curiosity ever since Voyagers 1 and 2 sent back pictures of the ring's unusual features. Some of these images showed three distinct ringlets with the outer two displaying a kinked and braided appearance. Many models have been proposed to explain the braiding seen in...
physics
10,521
Dusty Plasma Correlation Function Experiment
physics.space-ph
Dust particles immersed within a plasma environment, such as those in protostellar clouds, planetary rings or cometary environments, will acquire an electric charge. If the ratio of the inter-particle potential energy to the average kinetic energy is high enough the particles will form either a "liquid" structure with ...
physics
10,522
Finite Coulomb Crystal Formation
physics.space-ph
Dust particles immersed within a plasma environment, such as those found in planetary rings or comets, will acquire an electric charge. If the ratio of the inter-particle potential energy to average kinetic energy is large enough the particles will form either a "liquid" structure with short-range ordering or a crystal...
physics
10,523
Dust Grain Orbital Behavior Around Ceres
physics.space-ph
Many asteroids show indications they have undergone impacts with meteoroid particles having radii between 0.01 m and 1 m. During such impacts, small dust grains will be ejected at the impact site. The possibility of these dust grains (with radii greater than 2.2x10-6 m) forming a halo around a spherical asteroid (such ...
physics
10,524
Dynamics of Interplanetary Planetismal Rings
physics.space-ph
Among the problems yet to be solved by current theories of solar system formation is the origin of the Jupiter-family comets. Several possibilities are examined using a fifth-order Runge-Kutta algorithm.
physics
10,525
Orbits of Dust Ejecta From Ceres
physics.space-ph
The question of whether asteroid ejecta can enter stable orbits about the parent body is examined.
physics
10,526
Gravitational Interactions Between Protoplanets and Planetismal Disks of Equal Mass
physics.space-ph
Numerical simulations show that planetesimal systems with unevenly distributed masses may actually be more stable than those where all the bodies are of roughly equal size.
physics
10,527
Isolated Electrostatic Structures Observed Throughout the Cluster Orbit: Relationship to Magnetic Field Strength
physics.space-ph
Isolated electrostatic structures are observed throughout much of the 4 Re by 19.6 Re Cluster orbit. These structures are observed in the Wideband plasma wave instrument's waveform data as bipolar and tripolar pulses. These structures are observed at all of the boundary layers, in the solar wind and magnetosheath, and ...
physics
10,528
Relativistic Quasilinear Diffusion in Axisymmetric Magnetic Geometry for Arbitrary-Frequency Electromagnetic Fluctuations
physics.space-ph
A relativistic bounce-averaged quasilinear diffusion equation is derived to describe stochastic particle transport associated with arbitrary-frequency electromagnetic fluctuations in a nonuniform magnetized plasma. Expressions for the elements of a relativistic quasilinear diffusion tensor are calculated explicitly for...
physics
10,529
Titan's Atomic and Molecular Nitrogen Tori
physics.space-ph
Shematovich et al. (2003) recently showed plasma induced sputtering in Titan's atmosphere is a source of neutral nitrogen in Saturn's magnetosphere comparable to the photo-dissociation source. These sources form a toroidal nitrogen cloud roughly centered at Titan's orbital radius but gravitationally bound to Saturn. On...
physics
10,530
Stable Spatial Langmuir Solitons
physics.space-ph
We study localized two- and three-dimensional Langmuir solitons in the framework of model based on generalized nonlinear Schr\"odinger equation that accounts for local and nonlocal contributions to electron-electron nonlinearity. General properties of solitons are investigated analytically and numerically. Evolution of...
physics
10,531
Gravitation and Electromagnetic Wave Propagation with Negative Phase Velocity
physics.space-ph
Gravitation has interesting consequences for plane wave propagation in a vacuum. The propagation of plane waves with phase velocity directed opposite to the the time-averaged Poynting vector is investigated for a generally curved spacetime. Conditions for such negative-phase-velocity (NPV) propagation are established i...
physics
10,532
Reconnection in the Centre of the Near-Earth Plasma Sheet: Control by Plasma Drifts and Magnetic Flux Convection close to the Earth
physics.space-ph
Convection inside the magnetosphere can be regarded as the transfer of magnetic flux and plasma from the magnetotail into the nightside and then convection and drift from there to the dayside. As in many fluid flow situations, the downstream flow (the convection and drift to the dayside) is an important boundary condit...
physics
10,533
Fine structure of histograms of alpha-activity measurements depends on direction of alpha particles flow and the Earth rotation: experiments with collimators
physics.space-ph
The fine structure of histograms of measurements of 239Pu alpha-activity varies periodically, and the period of these variations is equal to sidereal day (1436 minutes). The periodicity is not observed in the experiments with collimator that restricts the alpha particles flow to be oriented to the Polar Star. Based on ...
physics
10,534
The specific form of histograms presenting the distribution of data of alpha-decay measurements appears simultaneously in the moment of New Moon in different points from Arctic to Antarctic
physics.space-ph
It is shown that fine structure of distributions of fluctuations in different processes depends on position of the Earth with respect of the Moon. The same form of histogram was observed at New Moon moment independently of geographic position of laboratory and local time. Possible origin of the phenomenon is discussed.
physics
10,535
Hypothetical Gravity Control and Possible Influence on Space Propulsion
physics.space-ph
In nearly all concepts invoked or proposed to change or shield gravity it is intuitively assumed that manipulation of gravity automatically leads to a breakthrough for propulsion. In this study it is shown, that even if gravity could be hypothetically controlled along the manipulation schemes outlined, the gains in ter...
physics
10,536
Experiments with rotating collimators cutting out pencil of alpha-particles at radioactive decay of Pu-239 evidence sharp anisotropy of space
physics.space-ph
As shown in our previous experiments fine structure of histograms of alpha-activity measurements serve as a sensitive tool for investigation of cosmo-physical influences. Particularly, the histograms structure is changed with the period equal to sidereal (1436 min) and solar (1440) day. It is similar with the high prob...
physics
10,537
Construction of a PZT Sensor Network for Low and Hypervelocity Impact Detection
physics.space-ph
Orbital debris is a constraint on the long-term health of any spacecraft and must be considered during mission planning. Varying mechanisms have been proposed to quantify the problem. Assessment of orbital debris employing ground-based methods such as radar can help determine where debris clouds are located as well as ...
physics
10,538
Cosmo-physical effects in structure of the daily and yearly periods of change in the shape of the histograms constructed by results of measurements of alpha-activity Pu-239
physics.space-ph
As shown in the previous publications, the shape of the histograms constructed by measurements of alpha-activity of samples of Pu-239, changes with periods equal approximately 24 hours, 27 days, and a year. At a higher resolution each of these periods splits as a minimum in two components: daily period consists of two:...
physics
10,539
Triangle for the entropic index q of non-extensive statistical mechanics observed by Voyager 1 in the distant heliosphere
physics.space-ph
Tsallis identified a set of numbers, the q-triplet, (qstat, qsen, qrel), for a system described by nonextensive statistical mechanics. The deviation of the q's from unity is a measure of the departure from thermodynamic equilibrium. We present observations of the q-triplets derived from two sets of daily averages of th...
physics
10,540
Secular cycle of the north-south solar asymmetry
physics.space-ph
The North-South asymmetry of solar activity has been recognized for different solar phenomena. Following Waldmeier, it is now assumed that solar activity dominates in the Northern solar hemisphere during the ascending part of the secular solar cycle, in the Southern one during the descending part, and in epochs of secu...
physics
10,541
Analyze of multistage transfer orbit to reach the GEO orbit in a rotational symmetric gravitational field
physics.space-ph
Placing satellites in geostationary obital (GEO) is propellant exigeant. It requires large propellant consumption that will take a large part of the total mass. Hence the interest is reduce the mass of propellant loaded both in the rocket and the satellite. Both for improving selection of transfer orbits and propellant...
physics
10,542
Simulation Study of a Positive Ionospheric Storm Phase Observed at Millstone Hill
physics.space-ph
Simulation results from the NRL ionospheric model SAMI2 indicate that the changes in the F-region over Millstone Hill during the geomagnetic storm beginning on 3 April 2004 are primarily due to the influence of a long-lasting eastward electric field, as was previously suggested by {\it Huang et al.} [2005]. A simulatio...
physics
10,543
Possible correlation between cosmic ray variation and atmosphere parameters (present status and future activities at BEO Moussala and Alomar observatory)
physics.space-ph
In this revue are presented several present activities and experiments at Alomar observatory and BEO Moussala and the possibility to investigate the influence of cosmic ray on climate parameters and the impact of cosmic ray to climate change. The general aim of these experiments is to study the possible correlation bet...
physics
10,544
Plasma Depletion and Mirror Waves Ahead of Interplanetary Coronal Mass Ejections
physics.space-ph
We find that the sheath regions between fast interplanetary coronal mass ejections (ICMEs) and their preceding shocks are often characterized by plasma depletion and mirror wave structures, analogous to planetary magnetosheaths. A case study of these signatures in the sheath of a magnetic cloud (MC) shows that a plasma...
physics
10,545
Solar Wind Electric Fields in the Ion Cyclotron Frequency Range
physics.space-ph
Measurements of fluctuations of electric fields in the frequency range from a fraction of one Hz to 12.5 Hz are presented, and corrected for the Lorentz transformation of magnetic fluctuations to give the electric fields in the plasma frame. The electric fields are large enough to provide the dominant force on the ions...
physics
10,546
Venus-Solar Wind Interaction: Asymmetries and the Escape of O+ Ions
physics.space-ph
We study the interaction between Venus and the solar wind using a global three-dimensional self-consistent quasi-neutral hybrid (QNH) model. The model treats ions (H+, O+) as particles and electrons as a massless charge neutralising fluid. In the analysed Parker spiral interplanetary magnetic field (IMF) case (IMF = [8...
physics
10,547
Asymmetries in Mars' Exosphere: Implications for X-ray and ENA Imaging
physics.space-ph
Observations and simulations show that Mars' atmosphere has large seasonal variations. Total atmospheric density can have an order of magnitude latitudinal variation at exobase heights. By numerical simulations we show that these latitude variations in exobase parameters induce asymmetries in the hydrogen exosphere tha...
physics
10,548
Resolved Hubble Space spectroscopy of ultracool binary systems
physics.space-ph
Using the low-resolution mode of the Space Telescope Imaging Spectrograph (STIS) aboard the \emph{Hubble Space Telescope} (HST), we have obtained spatially resolved spectra of 20 ultracool dwarfs. 18 of them belong to 9 known very low-mass binary systems with angular separations in the range 0.37-0.098 arcseconds. We h...
physics
10,549
Constraints on the Global Structure of Magnetic Clouds: Transverse Size and Curvature
physics.space-ph
We present direct evidence that magnetic clouds (MCs) have highly flattened and curved cross section resulting from their interaction with the ambient solar wind. Lower limits on the transverse size are obtained for three MCs observed by ACE and Ulysses from the latitudinal separation between the two spacecraft, rangin...
physics
10,550
Notes on the Dipole Coordinate System
physics.space-ph
A strong magnetic field can make it advantageous to work in a coordinate system aligned with dipolar field lines. This monograph collect the formulas for some of the most frequently used expressions and operations in dipole coordinates.
physics
10,551
Spacecraft at Small NEO
physics.space-ph
The impact risk has been sharply curtailed for the largest km-sized Near Earth Objects (NEOs) through a concerted period of observation spanning the last decade. Thus the risk of impact has now migrated to the smaller and more numerous members of the Near Earth Object (NEO) population. Characterization and mitigation m...
physics
10,552
Systematic Characterization of Low Frequency Electric and Magnetic Field Data Applicable to Solar Orbiter
physics.space-ph
We present a systematic and physically motivated characterization of incoherent or coherent electric and magnetic fields, as measured for instance by the low frequency receiver on-board the Solar Orbiter spacecraft. The characterization utilizes the 36 auto/cross correlations of the 3+3 complex Cartesian components of ...
physics
10,553
Neutron and Muon Flux Measurements at BEO Moussala towards to Space Weather Research
physics.space-ph
The existing and in development devices at Basic Environmental Observatory (BEO) Moussala are presented, precisely the experiments connected with space weather and astroparticle studies. The recent results of the secondary cosmic ray measurements using atmospheric Cherenkov light telescope are presented precisely the p...
physics
10,554
On the role of superconducting shields for propellantless propulsion
physics.space-ph
We critically review our recent claims that it is possible to obtain a propellantless propulsion device similar to electrodynamic tethers by means of a closed wire partially shielded by a superconductor from the outer magnetic field. We find that such a device is not possible as it violates basic physical laws. Further...
physics
10,555
A stability catalogue of the habitable zones in extrasolar planetary systems
physics.space-ph
In the near future there will be launched space missions (e.g. COROT, KEPLER), designed to detect Earth-like extrasolar planets. The orbital elements of these (still hypothetic) planets will contain some uncertainties, that can only be eliminated by careful dynamical investigations of the hosting planetary systems. The...
physics
10,556
Long-term variations in the correlation between NAO and solar activity: the importance of North-South solar activity asymmetry for atmospheric circulation
physics.space-ph
General atmospheric circulation is the system of atmospheric motions over the Earth on the scale of the whole globe. Two main types of circulation have been identified: zonal - characterized by low amplitude waves in the troposphere moving quickly from west to east, and meridional with stationary high amplitude waves w...
physics
10,557
Long-term variations in solar meridional circulation from geomagnetic data: implications for solar dynamo theory
physics.space-ph
Geomagnetic activity has two main peaks in the 11-year sunspot cycle caused by two types of solar agents: coronal mass ejections and high speed solar wind streams, whose variations in number and intensity are related to the variations in solar toroidal and poloidal fields, respectively. From the long-term variations in...
physics
10,558
Zakharov simulation study of spectral features of on-demand Langmuir turbulence in an inhomogeneous plasma
physics.space-ph
We have performed a simulation study of Langmuir turbulence in the Earth's ionosphere by means of a Zakharov model with parameters relevant for the F layer. The model includes dissipative terms to model collisions and Landau damping of the electrons and ions, and a linear density profile, which models the ionospheric p...
physics
10,559
Modelling long-term trends in lunar exposure to the Earth's plasmasheet
physics.space-ph
This paper shows how the exposure of the Moon to the Earth's plasmasheet is subject to decadal variations due to lunar precession. The latter is a key property of the Moon's apparent orbit around the Earth - the nodes of that orbit precess around the ecliptic, completing one revolution every 18.6 years. This precession...
physics
10,560
Structure on Interplanetary Shock Fronts: Type II Radio Burst Source Regions
physics.space-ph
We present \emph{in situ} observations of the source regions of interplanetary (IP) type II radio bursts, using data from the Wind spacecraft during the period 1996-2002. We show the results of this survey as well as in-depth analysis of several individual events. Each event analyzed in detail is associated with an int...
physics
10,561
Deformation of electron holes in phase space as prerequisite for narrow band maser emission: A qualitative discussion
physics.space-ph
A qualitative discussion is given of the role electron holes play in generating fine structure on the electron cyclotron maser radiation. It is argued that electron holes become deformed in phase space when interacting with an incomplete ring or horseshoe distribution which occurs in the presence of strong field aligne...
physics
10,562
Parker Problem in Hall Magnetohydrodynamics
physics.space-ph
Parker problem in Hall magnetohydrodynamics (MHD) is considered. Poloidal shear into the toroidal flow generated by the Hall effect is incorporated. This is found to lead to a {\it triple deck} structure for the Parker problem in Hall MHD, with the magnetic field falling off in the intermediate Hall-resistive region mo...
physics
10,563
Full-scale simulation study of a generalized Zakharov model for the generation of topside ionospheric turbulence
physics.space-ph
We present a full-scale simulation study of a generalized Zakharov model for the generation of the topside electrostatic turbulence due to the parametric instability during ionospheric heating experiments near the F region peak. The nonlinear tunneling of electromagnetic waves through the ionospheric layer is attribute...
physics
10,564
Comment on "CAWSES November 7-8, 2004, superstorm: Complex solar and interplanetary features in the post-solar maximum phase" by B. T. Tsurutani, E. Echer, F. L. Guarnieri, and J. U. Kozyra
physics.space-ph
Recently Tsurutani et al., (2008) (Paper 1) analyzed the complex interplanetary structures during 7 to 8 November, 2004 to identify their properties as well as resultant geomagnetic effects and the solar origins. Besides mentioned paper by Gopalswamy et al., (2006) the solar and interplanetary sources of geomagnetic st...
physics
10,565
Distinct Scaling Regimes of Energy Release Dynamics in the Nighttime Magnetosphere
physics.space-ph
Based on a spatiotemporal analysis of POLAR UVI images, we show that the auroral emission events that initiate equatorward of the isotropic boundary (IB) obtained from a time-dependent empirical model, have systematically steeper power-law slopes of energy, power, area and lifetime probability distributions compared to...
physics
10,566
Copernicus's epicycles from Newton's gravitational force law via linear perturbation theory in geometric algebra
physics.space-ph
We derive Copernicus's epicycles from Newton's gravitational force law by assuming that a planet's orbit is a perturbed circular orbit, with the perturbation defined to be co-rotating with the said orbit. We substitute this orbit expression into Newton's gravitation law and showed that the perturbation satisfies the li...
physics
10,567
Observational evidence of CMEs interacting in the inner heliosphere as inferred from MHD simulations
physics.space-ph
The interaction of multiple Coronal Mass Ejections (CMEs) has been observed by LASCO coronagraphs and by near-Earth spacecraft, and it is thought to be an important cause of geo-effective storms, large Solar Energetic Particles events and intense Type II radio bursts. New and future missions such as STEREO, the LWS Sen...
physics
10,568
On the competition between the mirror and electromagnetic ion cyclotron modes
physics.space-ph
We give a simple argument for the exclusive existence of mirror and electromaghetic ion cyclotron modes in anisotropic high-$\beta$ plasmas. It is shown that, in addition to a large domain of coexistence of both modes, two domains exist in parameter space $(A,\beta_\perp)$ where solely either mirror modes or electromag...
physics
10,569
Space Weathering on Near-Earth Objects investigated by neutral-particle detection
physics.space-ph
The ion-sputtering (IS) process is active in many planetary environments in the Solar System where plasma precipitates directly on the surface (for instance, Mercury, Moon, Europa). In particular, solar-wind sputtering is one of the most important agents for the surface erosion of a Near-Earth Object (NEO), acting toge...
physics
10,570
Microscopic Approach to Analyze Solar-Sail Space-Environment Effects
physics.space-ph
Near-sun space-environment effects on metallic thin films solar sails as well as hollow-body sails with inflation fill gas are considered. Analysis of interaction of the solar radiation with the solar sail materials is presented. This analysis evaluates worst-case solar radiation effects during solar-radiation-pressure...
physics
10,571
Data Analysis and Phase Ambiguity Removal in the ACES Microwave Link
physics.space-ph
The ACES (Atomic Clock Ensemble in Space) mission is an ESA - CNES project with the aim of setting up onboard the International Space Station (ISS) several highly stable atomic clocks with a microwave communication link (MWL). The specifications of the MWL are to perform ground to space time and frequency comparisons w...
physics
10,572
Resistive scales for collisionless reconnection in space plasma
physics.space-ph
We derive restrictions on collisional reconnection under the conditions in near-Earth space. The arguments are based on the precise definition and estimates of the resistive scale $L_\eta$ at the ion inertial site in collisionless reconnection, i.e. in the so-called `ion diffusion region' which is the region of Hall-cu...
physics
10,573
On the linear mirror mode threshold in high-$β$ space plasma
physics.space-ph
The linear threshold condition of the mirror mode including weak drift and finite Larmor radius effects is analysed and shown that it can be given to arbitrary precision in closed analytical form. Combined with observations of mirror modes in the magnetosheath it is shown that only magnetic `dips' are produced by the m...
physics
10,574
Solar-Terrestrial Simulation in the STEREO Era: The January 24-25, 2007 Eruptions
physics.space-ph
The SECCHI instruments aboard the recently launched STEREO spacecraft enable for the first time the continuous tracking of coronal mass ejections (CMEs) from the Sun to 1 AU. We analyze line-of-sight observations of the January 24-25, 2007 CMEs and fill the 20-hour gap in SECCHI coverage in January 25 by performing a n...
physics
10,575
Study of the Pioneer Anomaly: A scientific detective story
physics.space-ph
NASA's first two deep space missions, Pioneers 10 and 11, have been travelling through the outer solar system for three decades. A slight deviation from their calculated trajectories presents an as yet unsolved scientific mystery. The use of recently recovered Doppler and telemetry data may help us develop a better und...
physics
10,576
Laboratory evidence for the non-detection of excited nascent H2 in dark clouds
physics.space-ph
There has always been a great deal of interest in the formation of H2 as well as in the binding energy released upon its formation on the surface of dust grains. The present work aims at collecting experimental evidence for how the bond energy budget of H2 is distributed between the reaction site and the internal energ...
physics
10,577
Two recent kHz outer heliospheric radio emissions seen at Voyager 1-What are the interplanetary events that trigger them and where are these events when the radio emissions start?
physics.space-ph
We have examined instigating events at the Sun that may be responsible for two of the most recent outer heliospheric kHz emissions detected by the University of Iowa plasma wave detector on Voyager 1 starting at 2004.64 and 2006.39, respectively. These interplanetary events have been followed outward from the Sun using...
physics
10,578
Spacecraft Charging and Hazards to Electronics in Space
physics.space-ph
The interaction of a space system with its orbital environment is a major consideration in the design of any space system, since a variety of hazards are associated with the operation of spacecraft in the harsh space environment. In this brief review, two types of hazards to Earth-orbiting spacecraft are discussed: spa...
physics
10,579
A Zero-Gravity Instrument to Study Low Velocity Collisions of Fragile Particles at Low Temperatures
physics.space-ph
We discuss the design, operation, and performance of a vacuum setup constructed for use in zero (or reduced) gravity conditions to initiate collisions of fragile millimeter-sized particles at low velocity and temperature. Such particles are typically found in many astronomical settings and in regions of planet formatio...
physics
10,580
Two Types of Dynamic Cool Coronal Structures Observed with STEREO and HINODE
physics.space-ph
Solar coronal loops show significant plasma motions during their formation and eruption stages. Dynamic cool coronal structures, on the other hand, are often observed to propagate along coronal loops. In this paper, we report on the discovery of two types of dynamic cool coronal structures, and characterize their funda...
physics
10,581
Innovative methods of correlation and orbit determination for space debris
physics.space-ph
We propose two algorithms to provide a full preliminary orbit of an Earth-orbiting object with a number of observations lower than the classical methods, such as those by Laplace and Gauss. The first one is the Virtual debris algorithm, based upon the admissible region, that is the set of the unknown quantities corresp...
physics
10,582
An Analytical Method for Calculating the Satellite Bow Shock/Magnetopause Interception Positions and Times
physics.space-ph
This paper contains a presentation of analytical solution of the problem of calculating the places and moments of intersection of satellite trajectories with elements of the Earth's magnetosphere (bow shock and magnetopause). The satellite motion is presented in a Kepler's approximation. Magnetopause and bow shock are ...
physics
10,583
Improved orbit predictions using two-line elements
physics.space-ph
The density of orbital space debris constitutes an increasing environmental challenge. There are three ways to alleviate the problem: debris mitigation, debris removal and collision avoidance. This paper addresses collision avoidance, by describing a method that contributes to achieving a requisite increase in orbit pr...
physics
10,584
Analytical Method for Verification of a Satellite Pass over a Region of the Earth Surface
physics.space-ph
An analytical method is proposed in this work for verification whether an artificial earth satellite during its orbital motion passes over a region of the earth surface. The method is based on undisturbed Keppler's approximation of the orbit and approximation of the region by a circular segment S. In order to define th...
physics
10,585
Inhomogeneous whistler turbulence in low beta space plasmas
physics.space-ph
A nonlinear two dimensional fluid model of whistler turbulence is developed that nonlinearly couples wave magnetic field with electron density perturbations. This coupling leads essentially to finite compressibility effects in whistler turbulence model. Interestingly it is found from our simulations that despite strong...
physics
10,586
SAI: a compact atom interferometer for future space missions
physics.space-ph
Atom interferometry represents a quantum leap in the technology for the ultra-precise monitoring of accelerations and rotations and, therefore, for all the science that relies on the latter quantities. These sensors evolved from a new kind of optics based on matter-waves rather than light-waves and might result in an a...
physics
10,587
Kappa distributions: theory and applications in space plasmas
physics.space-ph
Particle velocity distribution functions (VDF) in space plasmas often show non Maxwellian suprathermal tails decreasing as a power law of the velocity. Such distributions are well fitted by the so-called Kappa distribution. The presence of such distributions in different space plasmas suggests a universal mechanism for...
physics
10,588
Simulation of Flux Emergence from the Convection Zone to the Corona
physics.space-ph
Here, we present numerical simulations of magnetic flux buoyantly rising from a granular convection zone into the low corona. We study the complex interaction of the magnetic field with the turbulent plasma. The model includes the radiative loss terms, non-ideal equations of state, and empirical corona heating. We find...
physics
10,589
Statistics of magnetic field fluctuations in a partially ionized space plasma
physics.space-ph
{\em Voyager 1} and {\em 2} data reveals that magnetic field fluctuations are compressive and exhibit a Gaussian distribution in the compressed heliosheath plasma, whereas they follow a lognormal distribution in a nearly incompressible supersonic solar wind plasma. To describe the evolution of magnetic field, we develo...
physics
10,590
From Micro- to Macro-scales in the Heliosphere and Magnetospheres
physics.space-ph
From a broader perspective, the heliosphere and planetary magnetospheres provide a test bed to explore the plasma physics of the Universe. In particular, the underlying nonlinear coupling of different spatial and temporal scales plays a key role in determining the structure and dynamics of space plasmas and electromagn...
physics
10,591
Dispersive magnetized waves in the solar wind plasma
physics.space-ph
We derive a generalized linear dispersion relation of waves in a strongly magnetized, compressible, homogeneous and isotropic quasineutral plasma. Starting from a two fluid model, describing distinguishable electron and ion fluids, we obtain a six order linear dispersion relation of magnetized waves that contains effec...
physics
10,592
Solar Polar Fields During Cycles 21 --- 23: Correlation with Meridional Flows
physics.space-ph
We have examined polar magnetic fields for the last three solar cycles, {$\it{viz.}$}, cycles 21, 22 and 23 using NSO Kitt Peak synoptic magnetograms. In addition, we have used SoHO/MDI magnetograms to derive the polar fields during cycle 23. Both Kitt Peak and MDI data at high latitudes (78${^{\circ}}$--90${^{\circ}}$...
physics
10,593
Unique Observations of a Geomagnetic SI^+ -- SI^- Pair: Solar Sources and Associated Solar Wind Fluctuations
physics.space-ph
The paper describes the occurrence of a pair of oppositely directed sudden impulses (SI), in the geomagnetic field ($\Delta$X), at ground stations, called SI${^{+}}$ -- SI${^{-}}$ pairs, that occurred between 1835 UT and 2300 UT on 23 April 1998. The SI${^{+}}$ -- SI${^{-}}$ pair, was closely correlated with correspond...
physics
10,594
Mapping of the cosmic ray events related to the solar activity for the period 2003-2005
physics.space-ph
The relationship between cosmic ray intensity decreases and solar events is still an open field of space research. In this work a complete study of solar events occurred from January 2003 to December 2005, is considered. This three-years time period characterized by an unexpected activity of the Sun was divided into 27...
physics
10,595
Dynamics of solar wind protons reflected by the Moon
physics.space-ph
Solar system bodies that lack a significant atmosphere and significant internal magnetic fields, such as the Moon and asteroids, have been considered as passive absorbers of the solar wind. However, ion observations near the Moon by the SELENE spacecraft show that a fraction of the impacting solar wind protons are refl...
physics
10,596
Solar wind driving of magnetospheric ULF waves: Field line resonances driven by dynamic pressure fluctuations
physics.space-ph
Several observational studies suggest that solar wind dynamic pressure fluctuations can drive magnetospheric ultra-low frequency (ULF) waves on the dayside. To investigate this causal relationship, we present results from Lyon-Fedder-Mobarry (LFM) global, three-dimensional magnetohydrodynamic (MHD) simulations of the s...
physics
10,597
Low-Velocity Impacts on PVDF Targets Using a Light Gas Gun
physics.space-ph
Orbital debris is a constraint on the long-term health of any spacecraft and must be consi-dered during mission planning. Varying mechanisms have been proposed to quantify the problem. Accurate in-situ data is essential with various types of sensors designed to detect orbital debris impacts employed on space missions s...
physics
10,598
How to defuse Earth impact threat announcements
physics.space-ph
Summary: In the past decade both scientists and laymen have probably heard at least once through the newspapers, TV and Internet that a new asteroid has been discovered with non-zero (sometimes "high") probability of collision with the Earth in the near future. Since early 2000's, such probabilities are routinely calcu...
physics
10,599
Ionizing wave via high-power HF acceleration
physics.space-ph
Recent ionospheric modification experiments with the 3.6 MW transmitter at the High Frequency Active Auroral Research Program (HAARP) facility in Alaska led to discovery of artificial ionization descending from the nominal interaction altitude in the background F-region ionosphere by ~60 km. This paper presents a physi...
physics