Introduction to Geology

This undergraduate level course presents a basic study in geology. It introduces major minerals and rock types, rock-forming processes, and time scales; temperatures, pressures, compositions, structure of the Earth, and measurement techniques; geologic structures and relationships observable in the field; sediment movement and landform development by moving water, wind, and ice; crustal processes and planetary evolution in terms of global plate tectonics with an emphasis on ductile and brittle processes

A Model of the Primordial Lunar Atmosphere

We create the first quantitative model for the early lunar atmosphere, coupled with a magma ocean crystallization model. Immediately after formation, the moon's surface was subject to a radiative environment that included contributions from the early Sun, a post-impact Earth that radiated like a mid-type M dwarf star, and a cooling global magma ocean. This radiative environment resulted in a largely Earth-side atmosphere on the Moon, ranging from approximately 10(exp 4) to approximately 10(exp 2) pascals, composed of heavy volatiles (Na and SiO). This atmosphere persisted through lid formation and was additionally characterized by supersonic winds that transported significant quantities of moderate volatiles and likely generated magma ocean waves. The existence of this atmosphere may have influenced the distribution of some moderate volatiles and created temperature asymmetries which influenced ocean flow and cooling. Such asymmetries may characterize young, tidally locked rocky bodies with global magma oceans and subject to intense irradiation

Editorial: Topical Collection on the Delivery of Water to Proto-Planets, Planets and Satellites

The review papers of this Topical Collection of Space Science Reviews devoted to the delivery of water to proto-planets, planets and satellites provide a coherent and comprehensive portrait of the knowledge in this fascinating field. We provide here a key of lecture of the volume, by summarizing the content of each review and proposing a logical order of reading, then attempting a broad summary of the state of the art as it emerges from the reviews altogether

Deciphering Redox State for a Metal-Rich World

Abstract The Psyche mission’s Oxidation-Reduction Working Group is focused on understanding, determining, and applying the redox state of (16) Psyche to understand the origin of a metal-rich world. The oxidation-reduction state of an asteroid, along with its temperature, parent body size, and composition, is a key parameter in determining the history of an asteroid. Determining the redox state from spacecraft data is most easily done by examining potential metal-oxide buffer pairs. The occurrence of Ni, Fe, C, Cr, P and Si, in that order, in the metal or sulfide phase of an asteroidal body indicates increasingly reduced conditions. Key observations by the Imager and Gamma-Ray and Neutron Spectrometer (GRNS) of Psyche can bracket the redox state using metal-oxide buffers. The presence of Fe,Ni metal can be confirmed by the ratios of Fe/O or Fe/Si and the concentration of Ni variability in metal across the asteroid can be determined by GRNS. The FeO concentration of silicates is complementary to the Ni concentration of metal and can be constrained using filters on the Imager. The presence of FeO in silicates from ground-based observations is one of the few measurements we already have of redox state, although available data permit a wide range of silicate compositions and mineralogies. The presence of C, P or Si concentrated in the metallic, Fe-rich portion of the asteroid, as measured by GRNS, or Ca-sulfide, determined by imaging, would indicate increasingly reducing conditions. Linkage to known types of meteorites, whether metal-rich chondrites, stony-irons or irons, expands the mineralogical, chemical and isotopic data not available from remote observations alone. Redox also controls both silicate and metal mineralogy, influencing differentiation, solidification, and subsolidus cooling, including the relative abundance of sulfur in the core and possible magnetic signatures. The redox state of Psyche, if a fully-differentiated metallic core, might constrain the location and timing of both the formation of Psyche and any oxidation it might have experienced

The scientific rationale for deployment of a long-lived geophysical network on the Moon

International audienc