Search Publications
Observational Aspects of Particle Acceleration in Large Solar Flares
Krucker, Säm; Raymond, John C.; Lin, Robert P. +1 more
Solar flares efficiently accelerate electrons to several tens of MeV and ions to 10 GeV. The acceleration is usually thought to be associated with magnetic reconnection occurring high in the corona, though a shock produced by the Coronal Mass Ejection (CME) associated with a flare can also accelerate particles. Diagnostic information comes from em…
LCROSS (Lunar Crater Observation and Sensing Satellite) Observation Campaign: Strategies, Implementation, and Lessons Learned
Terada, Hiroshi; de Pater, Imke; Vilas, Faith +84 more
NASA's LCROSS (Lunar Crater Observation and Sensing Satellite) mission was designed to explore the nature of previously detected enhanced levels of hydrogen near the lunar poles. The LCROSS mission impacted the spent upper stage of the launch vehicle into a permanently shadowed region of the lunar surface to create an ejecta plume. The resultant i…
Scalings, Cascade and Intermittency in Solar Wind Turbulence
Carbone, Vincenzo
Investigating in situ fluctuations in the interplanetary space, offers us a unique challenge to study scaling properties in a turbulent medium which cover a wide range of scales. This includes not only the inertial range, where turbulence can be described within a fluid-like approach, but also the high-frequency region, where a kinetic approach is…
Empirical Estimates of Martian Surface Pressure in Support of the Landing of Mars Science Laboratory
Withers, Paul
The aim of this work is to develop an empirical expression for diurnal mean martian surface pressure in support of the landing of Mars Science Laboratory. We evaluate the consistency of surface pressure measurements from four landers, Viking Lander 1, Viking Lander 2, Mars Pathfinder, and Phoenix, and one radio occultation experiment, Mars Global …
Implications of X-ray Observations for Electron Acceleration and Propagation in Solar Flares
Aschwanden, M. J.; Liu, W.; Zharkova, V. V. +6 more
High-energy X-rays and γ-rays from solar flares were discovered just over fifty years ago. Since that time, the standard for the interpretation of spatially integrated flare X-ray spectra at energies above several tens of keV has been the collisional thick-target model. After the launch of the Reuven Ramaty High Energy Solar Spectroscopic Imager (…
Ion Energization and Escape on Mars and Venus
Fedorov, A.; Lundin, R.; Dubinin, E. +4 more
Mars and Venus do not have a global magnetic field and as a result solar wind interacts directly with their ionospheres and upper atmospheres. Neutral atoms ionized by solar UV, charge exchange and electron impact, are extracted and scavenged by solar wind providing a significant loss of planetary volatiles. There are different channels and routes…
The Induced Magnetospheres of Mars, Venus, and Titan
Szego, K.; Fraenz, M.; Edberg, N. +4 more
This article summarizes and aims at comparing the main features of the induced magnetospheres of Mars, Venus and Titan. All three objects form a well-defined induced magnetosphere (IM) and magnetotail as a consequence of the interaction of an external wind of plasma with the ionosphere and the exosphere of these objects. In all three, photoionizat…
Properties of Energetic Ions in the Solar Atmosphere from γ-Ray and Neutron Observations
Vilmer, N.; MacKinnon, A. L.; Hurford, G. J.
Gamma-rays and neutrons are the only sources of information on energetic ions present during solar flares and on properties of these ions when they interact in the solar atmosphere. The production of γ-rays and neutrons results from convolution of the nuclear cross-sections with the ion distribution functions in the atmosphere. The observed γ-ray …
Review of Pi2 Models
Keiling, Andreas; Takahashi, Kazue
More than half a century after the discovery of Pi2 pulsations, Pi2 research is still vigorous and evolving. Especially in the last decade, new results have provided supporting evidence for some Pi2 models, challenged earlier interpretations, and led to entirely new models. We have gone beyond the inner magnetosphere and have explored the outer ma…
Properties of Near-Earth Magnetic Reconnection from In-Situ Observations
Fuselier, S. A.; Lewis, W. S.
Many properties of magnetic reconnection have been determined from in-situ spacecraft observations in the Earth's magnetosphere. Recent studies have focused on ion scale lengths and have largely confirmed theoretical predictions. In addition, some interesting features of reconnection regions on electron scale lengths have been identified. These re…