Iron abundance and magnetic permeability of the moon

A larger set of simultaneous data from the Apollo 12 lunar surface magnetometer and the Explorer 35 Ames magnetometer are used to construct a whole-moon hysteresis curve, from which a new value of global lunar permeability is determined to be mu = 1.012 + or - 0.006. The corresponding global induced dipole moment is 2.1 x 10 to the 18th power gauss-cu cm for typical inducing fields of .0001 gauss in the lunar environment. From the permeability measurement, lunar free iron abundance is determined to be 2.5 + or - 2.0 wt. %. Total iron abundance (sum of iron in the ferromagnetic and paramagnetic states) is calculated for two assumed compositional models of the lunar interior: a free iron/orthopyroxene lunar composition and a free iron/olivine composition. The overall lunar total iron abundance is determined to be 9.0 + or - 4.7 wt. %. Other lunar models with a small iron core and with a shallow iron-rich layer are discussed in light of the measured global permeability

Magnetism and the interior of the moon

The application of lunar magnetic field measurements to the study of properties of the lunar crust and deep interior is reviewed. Following a brief description of lunar magnetometers and the lunar magnetic environment, measurements of lunar remanent fields and their interaction with the solar plasma are discussed. The magnetization induction mode is considered with reference to lunar magnetic permeability and iron abundance calculations. Finally, electrical conductivity and temperature calculations from analyses of poloidal induction, for data taken in both the solar wind and in the geomagnetic tail, are reviewed

Lunar electrical conductivity, permeability,and temperature from Apollo magnetometer experiments

Magnetometers were deployed at four Apollo sites on the moon to measure remanent and induced lunar magnetic fields. Measurements from this network of instruments were used to calculate the electrical conductivity, temperature, magnetic permeability, and iron abundance of the lunar interior. Global lunar fields due to eddy currents, induced in the lunar interior by magnetic transients, were analyzed to calculate and electrical conductivity profile for the moon, and those profiles were used to calculate the lunar temperature for an assumed lunar material of olivine. Simultaneous measurements by magnetometers on the lunar surface and in orbit around the moon were use to construct a whole-moon hysteresis curve, from which the global lunar magnetic permeability is determined. Total iron abundance (sum of iron in the ferromagnetic and paramagnetic states) was calculated for two assumed compositional models of the lunar interior. Other lunar models with an iron core and with a shallow iron-rich layer also discussed in light of the measured global lunar permeability. Simultaneous magnetic field and solar plasma pressure measurements show that the remanent fields at the Apollo 12 and 16 sites interact with, and are compressed by, the solar wind. Velocities and thicknesses of the earth's magnetopause and bow shock were also estimated from simultaneous magnetometer measurements

Temperature and electrical conductivity of the lunar interior from magnetic transient measurements in the geomagnetic tail

Magnetometers were deployed at four Apollo sites on the moon to measure remanent and induced lunar magnetic fields. Measurements from this network of instruments were used to calculate the electrical conductivity, temperature, magnetic permeability, and iron abundance of the lunar interior. Global lunar fields due to eddy currents, induced in the lunar interior by magnetic transients in the geomagnetic tail field, were analyzed to calculate an electrical conductivity profile for the moon: the conductivity increases rapidly with depth from 10 to the minus 9 power mhos/meter at the lunar surface to .0001 mhos/meter at 200 km depth, then less rapidly to .02 mhos/meter at 1000 km depth. A temperature profile is calculated from conductivity: temperature rises rapidly with depth to 1100 K at 200 km depth, then less rapidly to 1800 K at 1000 km depth. Velocities and thicknesses of the earth's magnetopause and bow shock are estimated from simultaneous magnetometer measurements. Average speeds are determined to be about 50 km/sec for the magnetopause and 70 km/sec for the bow shock, although there are large variations in the measurements for any particular boundary crossing

A study of ignition phenomena of bulk metals by radiant heating

Early research on combustion of metals was motivated by the knowledge of the large heat release and corresponding high temperatures associated with metal-oxygen reactions. The advent of space flight brought about an increased interest in the ignition and combustion of metallic particles as additives in solid rocket propellants. More recently, attention has been given to the flammability properties of bulk, structural metals due to the number of accidental explosions of metal components in high-pressure oxygen systems. The following work represents a preliminary study that is part of a broader research effort aimed at providing further insight into the phenomena of bulk metal combustion by looking at the effects of gravity on the ignition behavior of metals. The scope of this preliminary experimental study includes the use of a non-coherent, continuous radiation ignition source, the measurement of temperature profiles of a variety of metals and a qualitative observation of the ignition phenomena at normal gravity. The specific objectives of the investigation include: (1) a feasibility study of the use of a continuous radiation source for metal ignition; (2) testing and characterization of the ignition behavior of a variety of metals; and (3) building a preliminary experimental database on ignition of metals under normal gravity conditions

Application of multispectral radar and LANDSAT imagery to geologic mapping in death valley

Side-Looking Airborne Radar (SLAR) images, acquired by JPL and Strategic Air Command Systems, and visible and near-infrared LANDSAT imagery were applied to studies of the Quaternary alluvial and evaporite deposits in Death Valley, California. Unprocessed radar imagery revealed considerable variation in microwave backscatter, generally correlated with surface roughness. For Death Valley, LANDSAT imagery is of limited value in discriminating the Quaternary units except for alluvial units distinguishable by presence or absence of desert varnish or evaporite units whose extremely rough surfaces are strongly shadowed. In contrast, radar returns are most strongly dependent on surface roughness, a property more strongly correlated with surficial geology than is surface chemistry

Evaluation of Recommended Sentencing Pilot Program

Missouri's prison population rose significantly through the 1990s and early 2000s. When compared nationally, Missouri's sentencing laws resulted in longer prison terms and in the imprisonment of a greater proportion of non-violent offenders. Imprisonment is the most costly alternative ($14,005 in Fiscal Year 05), but may not be the most effective alternative. In 2003, the Missouri General Assembly responded to these issues with the passage of Senate Bill 5 which, among other things, provided additional sentencing alternatives for nonviolent offenders. In partial response to the changes made in SB 5, the Missouri Sentencing Advisory Commission issued the Report on Recommended Sentencing, in 2004 which contained a proposed Sentencing Assessment Report, designed to replace the existing Pre-sentence Investigation Reports. The Sentencing Assessment Reports were implemented on a trial basis in six circuits in early 2005. This analysis provides an assessment of the new reports

Countryside biogeography of neotropical herbaceous and shrubby plants

As human impacts on the environment intensify, the future of plant and animal biodiversity will depend increasingly on the floras surviving in human-dominated "countryside" habitats. To begin to characterize these floras for the Neotropics, we investigated the richness and composition of herbaceous and shrubby plant communities in six forested and deforested habitats, in three replicated study areas (7.5-km in diameter), of southern Costa Rica. We chose habitat types that are common throughout the tropics, to begin building a general understanding of both the habitats of origin and the diversity of countryside floras. Focal forest habitats were understory, 1- to 2-year-old tree-fall gaps, and riverbanks, all in primary forest. Focal deforested habitats were ungrazed road verges, grazed pasture, and riverbanks in grazed pasture. Non-riverbank habitats were sampled both near and far from. forest edge. In total, we sampled 772 species from 79 families, similar to 40% of the non-tree plant diversity of the region. Only 6% of identified species are known to be exotic. In each study area, understory and pasture plots were consistently species poor, while tree-fall gaps and road verges near forest were consistently the most species-rich habitats. In each study area, we found the same proportion of species restricted to forested habitats (similar to 45%) and deforested habitats (similar to 37%), and the same proportion of "countryside-habitat generalists" ( similar to 18%) occurring in both forested and deforested habitats. However, different forested habitats supported different proportions of country side-habitat generalists in each study area, although understory plots consistently 'supported the fewest generalists. Among forested habitats, riverbanks were the most similar floristically to deforested habitats. Pasture riverbanks and road verges near forest supported plant communities most similar to those in forested habitats. The uniqueness and richness of each habitat suggests that countrysides with diverse land uses can support many native herbaceous and shrubby plant species. As it becomes increasingly difficult to protect large tracts of undisturbed tropical forest, we suggest that conservation goals expand to encompass maintenance of heterogeneity in countryside landscapes