With a grain of salt: what halite has to offer to discussions on the origin of life

This experimental study investigated how the dynamics of the crystallization of the evaporite mineral halite could affect the accumulation and preservation of organic macromolecules present in the crystallizing solution. Halite was grown under controlled conditions in the presence of polymer nanoparticles that acted as an analog to protocellular material. Optical microscopy, atomic force microscopy, and laser scanning confocal fluorescence microscopy were used to trace the localization of the nanoparticles during and after growth of halite crystals. The present study revealed that the organic nanoparticles were not regularly incorporated within the halite, but were very concentrated on its surfaces. Their distribution was controlled dominantly by the morphologic surface features of the mineral rather than by specific molecular interactions with an atomic plane of the mineral. This means that the distribution of organic molecules was controlled by surfaces like those of halite's evaporitic growth forms. The experiments with halite also demonstrated that a mineral need not continuously incorporate organic molecules during its crystallization to preserve those molecules: After rejection by (non-incorporation into) the crystallizing halite, the organic nanoparticles increased in concentration in the evaporating brine. They ultimately either adsorbed in rectilinear patterns onto the hopper-enhanced surfaces and along discontinuities within the crystals, or they were encapsulated within fluid inclusions. Of additional importance in origin-of-life considerations is the fact that halite in the natural environment rapidly can change its role from that of a protective repository (in the absence of water) to that of a source of organic particles (as soon as water is present) when the mineral dissolves.     

Spacecraft on-orbit deployment anomalies: What can be done?

On-orbit anomalies related to the deployment of spacecraft appendage and possible causes of such failures are considered. The discussion covers mechanical launch loading, on-orbit thermal and solar concerns, reliability of spacecraft pyrotechnics, and practical limitations of ground-based deployment testing. Lessons learned from the successful recovery of the Telesat Canada Anik-E2 satellite in 1991 are examined     

Geometric accuracy in airborne SAR images

Uncorrected across-track motions of a synthetic aperture radar (SAR) platform can cause both a severe loss of azimuthal positioning accuracy in, and defocusing of, the resultant SAR image. It is shown how the results of an autofocus procedure can be incorporated in the azimuth processing to produce a fully focused image that is geometrically accurate in azimuth. Range positioning accuracy is also discussed, leading to a comprehensive treatment of all aspects of geometric accuracy. The system considered is an X-band SAR     

Solar-cometary relations and the events of June–August 1972

Evidence for correlations of brightness fluctuations of heads of comets with solar and solar-related phenomena is presented, and the examples of Comet Schwassmann-Wachmann (1) and Giacobini-Zinner in 1959 and 1972 are examined. Brightness behavior of comets and the general level of solar activity in the eleven-year cycle appear to be statistically related. At present the responses of individual comets to solar events are not sufficiently well calibrated to permit using them as reliable interplanetary probes.     

Helium, Oxygen, Proton, and Electron (HOPE) Mass Spectrometer for the Radiation Belt Storm Probes Mission

The HOPE mass spectrometer of the Radiation Belt Storm Probes (RBSP) mission (renamed the Van Allen Probes) is designed to measure the in situ plasma ion and electron fluxes over 4π sr at each RBSP spacecraft within the terrestrial radiation belts. The scientific goal is to understand the underlying physical processes that govern the radiation belt structure and dynamics. Spectral measurements for both ions and electrons are acquired over 1 eV to 50 keV in 36 log-spaced steps at an energy resolution ΔE _FWHM/E≈15 %. The dominant ion species (H⁺, He⁺, and O⁺) of the magnetosphere are identified using foil-based time-of-flight (TOF) mass spectrometry with channel electron multiplier (CEM) detectors. Angular measurements are derived using five polar pixels coplanar with the spacecraft spin axis, and up to 16 azimuthal bins are acquired for each polar pixel over time as the spacecraft spins. Ion and electron measurements are acquired on alternate spacecraft spins. HOPE incorporates several new methods to minimize and monitor the background induced by penetrating particles in the harsh environment of the radiation belts. The absolute efficiencies of detection are continuously monitored, enabling precise, quantitative measurements of electron and ion fluxes and ion species abundances throughout the mission. We describe the engineering approaches for plasma measurements in the radiation belts and present summaries of HOPE measurement strategy and performance.     

The Network Vehicle-a glimpse into the future of mobile multi-media

The Network Vehicle is the Delphi Automotive Systems' vision for the future convergence of computers, the communications infrastructure, and the automobile. It features many advanced functions such as: satellite video, Internet access, virtual navigation, remote vehicle diagnostics and control, games, mobile office, automotive web site, and customized real-time stock quotes and sports scores. These features are enabled by an integrated planar antenna that is capable of multiple satellite reception, a client-server network architecture, and unique human-vehicle-interfaces such as color reconfigurable head-up and head-down displays, steering wheel controls, voice recognition, text-to-speech, and large touch screen active matrix liquid crystal displays (LCDs). The software applications are written in Java, using Application Programming Interfaces (APIs) to reduce the complexity and cost of the source code     

The production of oxidants in Europa's surface

The oxidants produced by radiolysis and photolysis in the icy surface of Europa may be necessary to sustain carbon-based biochemistry in Europa's putative subsurface ocean. Because the subduction of oxidants to the ocean presents considerable thermodynamic challenges, we examine the formation of oxygen and related species in Europa's surface ice with the goal of characterizing the chemical state of the irradiated material. Relevant spectral observations of Europa and the laboratory data on the production of oxygen and related species are first summarized. Since the laboratory data are incomplete, we examine the rate equations for formation of oxygen and its chemical precursors by radiolysis and photolysis. Measurements and simple rate equations are suggested that can be used to characterize the production of oxidants in Europa's surface material and the chemical environment produced by radiolysis. Possible precursor molecules and the role of radical trapping are examined. The possibility of oxygen reactions on grain surfaces in Europa's regolith is discussed, and the earlier estimates of the supply of O(2) to the atmosphere are increased.     

Large-Scale Structure and Dynamics of the Magnetotails of Mercury,Earth, Jupiter and Saturn

Spacecraft observations have established that all known planets with an internal magnetic field, as part of their interaction with the solar wind, possess well-developed magnetic tails, stretching vast distances on the nightside of the planets. In this review paper we focus on the magnetotails of Mercury, Earth, Jupiter and Saturn, four planets which possess well-developed tails and which have been visited by several spacecraft over the years. The fundamental physical processes of reconnection, convection, and charged particle acceleration are common to the magnetic tails of Mercury, Earth, Jupiter and Saturn. The great differences in solar wind conditions, planetary rotation rates, internal plasma sources, ionospheric properties, and physical dimensions from Mercury’s small magnetosphere to the giant magnetospheres of Jupiter and Saturn provide an outstanding opportunity to extend our understanding of the influence of such factors on basic processes. In this review article, we study the four planetary environments of Mercury, Earth, Jupiter and Saturn, comparing their common features and contrasting their unique dynamics.     

Towards Synthesis of Solar Wind and Geomagnetic Scaling Exponents: A Fractional Lévy Motion Model

Mandelbrot introduced the concept of fractals to describe the non-Euclidean shape of many aspects of the natural world. In the time series context, he proposed the use of fractional Brownian motion (fBm) to model non-negligible temporal persistence, the ‘Joseph Effect’; and Lévy flights to quantify large discontinuities, the ‘Noah Effect’. In space physics, both effects are manifested in the intermittency and long-range correlation which are by now well-established features of geomagnetic indices and their solar wind drivers. In order to capture and quantify the Noah and Joseph effects in one compact model, we propose the application of the ‘bridging’ fractional Lévy motion (fLm) to space physics. We perform an initial evaluation of some previous scaling results in this paradigm, and show how fLm can model the previously observed exponents. We suggest some new directions for the future.     

Future NASA spaceborne SAR missions

Two Earth-orbiting radar missions are planned for the near future by NASA-Shuttle Radar Topography Mission (SRTM) and LightSAR. The SRTM will fly aboard the Shuttle using interferometric synthetic aperture radar (IFSAR) to provide a global digital elevation map. SRTM is jointly sponsored by NASA and the National Imagery and Mapping Agency (NIMA). The LightSAR will utilize emerging technology to reduce mass and life-cycle costs for a mission to acquire SAR data for Earth science and civilian applications and to establish commercial utility. LightSAR is sponsored by NASA and industry partners. The use of IFSAR to measure elevation is one of the most powerful and practical applications of radar. A properly equipped spaceborne IFSAR system can produce a highly accurate global digital elevation map, including cloud-covered areas, in significantly less time and at significantly lower cost than other systems. For accurate topography over a large area, the interferometric measurements can be performed simultaneously in physically separate receive systems. Since LightSAR offers important benefits to both the science community and US industry, an innovative government-industry teaming approach is being explored, with industry sharing the cost of developing LightSAR in return for commercial rights to its data and operational responsibility. LightSAR will enable mapping of surface change. The instrument's high-resolution mapping, along with its quad polarization, dual polarization, interferometric and ScanSAR modes will enable continuous monitoring of natural hazards, Earth's surface deformation, surface vegetation change, and ocean mesoscale features to provide commercially viable and scientifically valuable data products. Advanced microelectronics and lightweight materials will increase LightSAR's functionality without increasing the mass. Dual frequency L/X-band designs have been examined