The Gruithuisen region in northern Oceanus Procellarum on the Moon contains three distinctive domes interpreted as nonmare volcanic features of Imbrian age. A 4 d extravehicular activity (EVA), four-astronaut sortie mission to explore these enigmatic features and the surrounding terrain provides the opportunity to address key outstanding lunar science questions. The landing site is on the mare south of Gruithuisen 3 (36.22°N, 40.60°W). From this site, diverse geologic terrains and features are accessible, including highlands, dome material, mare basalts, multiple craters, small rilles, and a negative topographic feature of unknown origin. Preliminary mission planning is based on Clementine multispectral data, Lunar Prospector geochemical estimates, and high-resolution (0.5 m/pixel) stereo images from the Lunar Reconnaissance Orbiter Narrow Angle Camera. Science objectives for the mission include: (1) determining the nature of the domes, (2) identifying and measuring the distribution of any potassium, rare earth elements, and phosphorus (KREEP)- and thorium-rich materials, (3) collecting samples for age dating of key units to investigate the evolution of the region, and (4) deploying a passive seismic grid as part of a global lunar network. Satisfying the science objectives requires 7 h, ~20 km round-trip EVAs, and significant time driving on slopes up to ~15°.

Abstract Volcanism and tectonism are the dominant endogenic means by which planetary surfaces change. This book, in general, and this overview, in particular, aim to encompass the broad range in character of volcanism, tectonism, faulting and associated interactions observed on planetary bodies across the inner solar system – a region that includes Mercury, Venus, Earth, the Moon, Mars and asteroids. The diversity and breadth of landforms produced by volcanic and tectonic processes are enormous, and vary across the inventory of inner solar system bodies. As a result, the selection of prevailing landforms and their underlying formational processes that are described and highlighted in this review are but a primer to the expansive field of planetary volcanism and tectonism. In addition to this extended introductory contribution, this Special Publication features 21 dedicated research articles about volcanic and tectonic processes manifest across the inner solar system. Those articles are summarized at the end of this review.

Abstract Future success in exploration and human habitation of the solar system will depend on space missions and settlements becoming more self-sustaining through exploitation of extraterrestrial (i.e., local) energy and material resources. For example, the Moon contains a wide variety of energy minerals and other resources that can potentially be used for manufacture of propellants for space transportation, volatiles for manufacture of chemicals, and metals for construction of solar power facilities, industrial plants, and structures for human habitation. If water ice in polar regions on the Moon is proven to exist in large quantities, these resources could not only support human habitation but could also be used to manufacture rocket propellants, reducing dependency on Earth for these resources, thereby making human space exploration more economically viable. Moreover, the lower gravity well of the Moon could be used as a launching site for missions to Mars and other worlds in the solar system, given the possibility of water-ice and other lunar resources. New exploration tools will need to be developed to fully and accurately characterize the potential lunar resource base. For example, detection and quantification of suspected water-ice resource in lunar polar regions in recent missions involve an array of technologies not commonly used in hydrocarbon exploration on Earth, such as synthetic aperture radar, epithermal neutron detectors, and imaging of reflected ultraviolet starlight using Lyman-alpha scattering properties. Optimal locations for potential lunar bases and industrial facilities reflect several factors that include the distribution of water ice, volatiles (nitrogen), nuclear materials (helium-3, thorium, and uranium), and metals (titanium, magnesium, and iron). Other important factors are the duration of insolation (sunlight), where solar power facilities could be constructed in polar areas with constant or near-constant illumination, as well as strategies that involve key orbital positions (Lagrangian points) to maximize fuel resources using less overall delta-v, defined as incremental change in spacecraft velocity to achieve a new orbital configuration.