Ejecta types on Ganymede and Callisto

Ejecta types on Ganymede and Callisto have been identified from Voyager 1 and 2 images. Image resolution used range from approx. 0.6 to approx. 4 km/pxl, which allowed the surveying of almost all of the mappable surface of the two satellites. Seven ejecta classes were identified on Voyager images of Ganymede on the basis of albedo pattern and type of terminus. The ejecta of different terrains on ejecta characteristics were investigated for the most populated ejecta types. Two major ejecta types were identified on Callisto; both have counterparts on Ganymede. Type C1 has a uniformly high albedo and a sharp terminus. Type C2 has a gradational terminus and a moderate albedo. The similarity in ejecta types on Ganymede and Callisto may indicate similarities in the near surface environment of the two satellites, with different ejecta types representing several possible conditions for the impact environment

Sand and Dust on Mars

Mars is a planet of high scientific interest. Various studies are currently being made that involve vehicles that have landed on Mars. Because Mars is known to experience frequent wind storms, mission planners and engineers require knowledge of the physical and chemical properties of Martian windblown sand and dust, and the processes involved in the origin and evolution of sand and dust storms

Volcanic features of Hawaii. A basis for comparison with Mars

Despite the difference in size Martian and Hawaiian volcanoes have numerous characteristics in common. Specific features such as lava channels, collapsed lava tubes, levees and flow fronts, all very common in Hawaii, are also abundant on the flanks of some of the Martian volcanoes. Striking differences also exist, such as the apparent lack of radial rift zones on some Martian volcanoes and the paucity of cinder and spatter cones. Some of the best photographs of Martian and Hawaiian volcanic features are presented. Descriptive legends are provided for each picture. An overview of the geological processes and structures depicted is included

Remote estimation of soil moisture

Two methods under consideration for making remote estimates of soil moisture involve measurements made in electromagnetic spectral region of 0.4 to 14.0 micrometers: (1) spectral reflectance, (2) soil temperature

Scientific Results of the Nasa-sponsored Study Project on Mars: Evolution of Its Climate and Atmosphere

The scientific highlights of the Mars: Evolution of its Climate and Atmosphere (MECA) study project are reviewed and some of the important issues in Martian climate research that remain unresolved are discussed

Use of visible, near-infrared, and thermal infrared remote sensing to study soil moisture

Two methods are described which are used to estimate soil moisture remotely using the 0.4- to 14.0 micron wavelength region: (1) measurement of spectral reflectance, and (2) measurement of soil temperature. The reflectance method is based on observations which show that directional reflectance decreases as soil moisture increases for a given material. The soil temperature method is based on observations which show that differences between daytime and nighttime soil temperatures decrease as moisture content increases for a given material. In some circumstances, separate reflectance or temperature measurements yield ambiguous data, in which case these two methods may be combined to obtain a valid soil moisture determination. In this combined approach, reflectance is used to estimate low moisture levels; and thermal inertia (or thermal diffusivity) is used to estimate higher levels. The reflectance method appears promising for surface estimates of soil moisture, whereas the temperature method appears promising for estimates of near-subsurface (0 to 10 cm)

Conversational Data Analysis as an Altered State of Consciousness

Norman Nie was nothing if not candid as to the reasons why I was chosen to speak to you this evening. He said, We want somebody who doesn\u27t know a bit from a bite, but who has had a lot of experience with SCSS. I qualify on both counts. Biting is something you do to a bullet, and bit is what\u27s left over in the paycheck after the government takes its taxes away. As for the use of SCSS I\u27ve done most of a book relying solely on my portable T1 terminal and, with some risk of having a giant skyhook come down and removing me from the scene tonight, I think I can say I have analyzed more data with it than Norman has

Images of God in the Movies

In the following essay I identify some of the images of God I have found in contemporary, popular movies. Some of these are visual images of God, while others are conceptions of what God expects from us or for us. I conclude that the God of the movies is both gentle and tough, merciful and stern, caring and just. Movies may emphasize the merciful, but the images of God include both mercy and justice and the emphasis mirrors the emphasis on mercy in our own culture. We are, on the whole, optimists, and the images of God in the movies support such optimism

Surface Profiling of Natural Dust Devils

We present results from the first high-resolution near-surface profiles conducted on dust devil wind fields. These results are integrated with extensive geologic mapping to understand the factors that influence vortex generation and erosive efficacy