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Today the field of planetary X-rays is very dynamic and in the forefront of new research. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus, the rings of Saturn, the coronae (exospheres) of Earth, Mars and Venus, and the heliosphere. Scattering of solar X-rays mainly produces the non-auroral X-ray emissions from Jupiter, Saturn, and Earth, those from the disk of Mars and Venus, from the surface of the Moon, and from the rings of Saturn. The X-ray emission from comets, the heliosphere, the geocorona, and the Martian and Venusian exospheres are all largely produced in charge exchange collision between highly ionized minor heavy ions in the solar wind and gaseous neutral species in the bodies’ atmosphere—a process known as solar wind charge exchange (SWCX). Thus, both, the solar radiation and out-flowing plasma from the Sun (solar wind) power the production of X-ray emission from solar system bodies. A brief overview on X-rays from the solar system bodies and their connection with solar X-rays and solar wind is presented in this paper. [ABSTRACT FROM AUTHOR]

We present results from our enhanced statistical equilibrium and time-step codes for atmospheric modeling. In particular we use these results to illustrate the role of electron-driven processes in atmospheric phenomena and the sensitivity of the model results to data inputs such as integral cross sections, dissociative recombination rates and chemical reaction rates. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Summary form only given. Appropriate imaging technology either from ground or satellite can reveal the instantaneous two-dimensional character of plasma dynamics in the near-Earth environment. Particularly conducive to such measurements are the vortical structures which develop with varying horizontal dimensions in the ionosphere near an altitude of 120 km. UV measurements made from the Viking satellite have for the first time shown the development of such spatial features at all local times within the auroral distribution, and they always have a counterclockwise sense when viewed along the local magnetic field vector. Scale sizes vary from instrumental threshold (~20 km) to in excess of 1000 km with the larger scale sizes primarily associated with substorm activity in the midnight sector. Of special significance is the dynamic nature (lifetimes as short as 2 min) of multiple vortices (sometimes up to 7) which can extend over several thousand kilometers. These features are thought to be the result of an exponential growth along a magnetic field line of an upward field-aligned current perturbation. Such perturbations are the results of velocity/density shears along one of the many boundaries in the magnetosphere [ABSTRACT FROM PUBLISHER]

Summary form only given. The double layers that are thought to accelerate the auroral electron streams exist in the Earth's plasma-filled magnetized flux tubes. Not much is known about these structures, e.g., whether they are tilted with respect to the magnetic field, how many spatial dimensions are relevant, how long is their lifetime, their relation to wave turbulence, etc. In order to study these questions, a magnetized plasma device has been constructed with two very efficient RF loop antenna plasma sources that generate a radially and axially uniform plasma and allow for controllable boundary conditions. The scaling to spacelike parameters is good for a laboratory device with a collisionless plasma with a radius of approximately 20 cm and a length of 70 cm. The plasma density can be varied from n e~106-1011 cm-3, electron temperature Te~2-5 eV (Te≫Ti), with a background magnetic field B0<200 G and a fill pressure of 7-10×10-5 torr. The plasma radius is many gyro radii across. The Debye lengths are much smaller than the plasma dimensions [ABSTRACT FROM PUBLISHER]