Orbit determination for next generation space clocksOver the last decade of the 20th century and the first few years of the 21st, the uncertainty of atomic clocks has decreased by about two orders of magnitude, passing from the low 10-14 to below…Loïc Duchayne, Flavien Mercier, Peter Wolf·Aug 17, 2007SaveLearn
Nonlinear analysis of a simple model of temperature evolution in a satelliteWe analyse a simple model of the heat transfer to and from a small satellite orbiting round a solar system planet. Our approach considers the satellite isothermal, with external heat input from the…Jose Gaite, Angel Sanz-Andrés, Isabel Pérez-Grande·Jul 23, 2007SaveLearn
Magnetic double gradient instability and flapping waves in a current sheetA new kind of magnetohydrodynamic instability and waves are analyzed for a current sheet in the presence of a small normal magnetic field component varying along the sheet. These waves and…N. V. Erkaev, V. S. Semenov, H. K. Biernat·Jul 6, 2007SaveLearn
Examining the Location of the Magnetopause in an Undergraduate LabIntegrating areas of current research into undergraduate physics labs can be a difficult task. The location of the magnetopause is one problem that can be examined with no prior exposure to space…James P. Crumley, Ari D. Palczewski, Stephen A. Kaster·Jun 14, 2007SaveLearn
Radial distribution of the inner magnetosphere plasma pressure using low-altitude satellite data during geomagnetic storm: the March 1-8, 1982 EventPlasma pressure distribution in the inner magnetosphere is one of the key parameters for understanding the main magnetospheric processes including geomagnetic storms and substorms. However, the…M. Stepanova, E. E. Antonova, J. M. Bosqued·Jun 6, 2007SaveLearn
Modelling long-term trends in lunar exposure to the Earth's plasmasheetThis 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…Mike Hapgood·May 7, 2007SaveLearn
Zakharov simulation study of spectral features of on-demand Langmuir turbulence in an inhomogeneous plasmaWe 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…Bengt Eliasson, Bo Thidé·Apr 25, 2007SaveLearn
The Orientation of the Reconnection X-lineWe propose a criterion for identifying the orientation of the X-line when two regions of plasma with arbitrary densities, temperatures, and magnetic fields undergo reconnection. The X-line points in…M. Swisdak, J. F. Drake·Apr 20, 2007SaveLearn
High-altitude signatures of ionospheric density depletions caused by field-aligned currentsWe present Cluster measurements of large electric fields correlated with intense downward field-aligned currents, and show that the data can be reproduced by a simple model of ionospheric plasma…T. Karlsson, N. Brenning, O. Marghitu et al.·Apr 12, 2007SaveLearn
Long-term variations in solar meridional circulation from geomagnetic data: implications for solar dynamo theoryGeomagnetic 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…K. Georgieva, B. Kirov·Mar 19, 2007SaveLearn
Large parallel and perpendicular electric fields on electron spatial scales in the terrestrial bow shockLarge parallel (≤ 100 mV/m) and perpendicular (≤ 600 mV/m) electric fields were measured in the Earth's bow shock by the vector electric field experiment on the Polar satellite. These…S. D. Bale, F. S. Mozer·Mar 8, 2007SaveLearn
Self-similar signature of the active solar corona within the inertial range of solar wind turbulenceWe quantify the scaling of magnetic energy density in the inertial range of solar wind turbulence seen in-situ at 1AU with respect to solar activity. At solar maximum, when the coronal magnetic field…K. Kiyani, S. C. Chapman, B. Hnat et al.·Feb 14, 2007SaveLearn
Long-term variations in the correlation between NAO and solar activity: the importance of North-South solar activity asymmetry for atmospheric circulationGeneral 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…Katya Georgieva, Boian Kirov, Peter Tonev et al.·Feb 6, 2007SaveLearn
Non-Markov statistical effects of X-ray emission intensity of the microquasar GRS 1915+105In this paper we develop the new approach in time series analysis with a variable time step and present the results of quantitative and qualitative estimation of randomness and regularity, and the…R. M. Yulmetyev, S. A. Demin, R. M. Khusnutdinov et al.·Feb 6, 2007SaveLearn
A stability catalogue of the habitable zones in extrasolar planetary systemsIn 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…Zs. Sándor, Á. Süli, B. Érdi et al.·Jan 6, 2007SaveLearn
On the role of superconducting shields for propellantless propulsionWe 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…L. Bergamin, D. Izzo, A. Pinchook·Dec 13, 2006SaveLearn
Neutron and Muon Flux Measurements at BEO Moussala towards to Space Weather ResearchThe 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…Alexander Mishev·Dec 8, 2006SaveLearn
Systematic Characterization of Low Frequency Electric and Magnetic Field Data Applicable to Solar OrbiterWe 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…Jan E. S. Bergman, Tobia D. Carozzi·Nov 7, 2006SaveLearn
From Theoretical Foundation to Invaluable Research Tool: Modern Hybrid SimulationsIn many plasmas, in particular in space science, protons govern much of the essential physics. Minority ions, suprathermal tails, and electrons at times account for additional details. However,…D. Krauss-Varban·Oct 18, 2006SaveLearn
Gravity Control Propulsion: Towards a General Relativistic ApproachEvaluation of gravity control concepts should be examined with respect to currently known physical theories. In this work we study the hypothetical conversion of gravitational potential energy into…O. Bertolami, F. G. Pedro·Oct 16, 2006SaveLearn
Radiation Hazard of Relativistic Interstellar FlightFrom the point of view of radiation safety, interstellar space is not an empty void. Interstellar gas and cosmic rays, which consist of hydrogen and helium nucleons, present a severe radiation hazard…Oleg G. Semyonov·Oct 5, 2006SaveLearn
Wave turbulence in incompressible Hall MHDWe investigate the steepening of the magnetic fluctuation power law spectra observed in the inner solar wind for frequencies higher than 0.5 Hz. This high frequency part of the spectrum may be…S. Galtier·Aug 23, 2006SaveLearn
Spacecraft at Small NEOThe 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…Dan Scheeres·Aug 15, 2006SaveLearn
Threat Mitigation: The Gravity TractorThe Gravity Tractor (GT) is a fully controlled asteroid deflection concept using the mutual gravity between a robotic spacecraft and an asteroid to slowly accelerate the asteroid in the direction of…Russell Schweickart, Clark Chapman, Dan Durda et al.·Aug 15, 2006SaveLearn
Threat Mitigation: The Asteroid TugboatThe Asteroid Tugboat (AT) is a fully controlled asteroid deflection concept using a robotic spacecraft powered by a high efficiency, electric propulsion system (ion or plasma) which docks with and…Russell Schweickart, Clark Chapman, Dan Durda et al.·Aug 15, 2006SaveLearn