Publications

Every astronaut who walked on the Moon trained in Flagstaff, AZ. In the early 1960s, scientists at the newly formed United States Geological Survey (USGS) Branch of Astrogeology led this training, teaching geologic principals and field techniques to the astronaut crews. USGS scientists and engineers also developed and tested scientific instrument prototypes, and communication and transportation

This document is the final report of the Ice and Climate Evolution Science Analysis Group (ICESAG) that was formed by the Mars Exploration Program Analysis Group (MEPAG) as part of its preparations for the upcoming NASA Planetary Science Decadal Survey for 2023 through 2032 (see §1). Through telecons, one face-to-face meeting, and discussions with experts in relevant topics, ICE-SAG has identified

Lobate stony landforms occur on steep slopes at high latitudes on Mars. We demonstrate active boulder movement at seven such sites. Sub-meter-scale boulders frequently move distances of a few meters. The movement is concentrated in the vicinity of the lobate landforms but also occurs on other slopes. This provides evidence for a new, common style of activity on Mars, which may play an important ro

Surface debris covers much of the western portion of the McMurdo Ice Shelf and has a strong influence on the local surface albedo and energy balance. Differential ablation between debris-covered and debris-free areas creates an unusual heterogeneous surface of topographically low, high-ablation, and topographically raised (‘pedestalled’), low-ablation areas. Analysis of Landsat and MODIS satellite

Mars is dry today, but numerous precipitation-fed paleo-rivers are found across the planet’s surface. These rivers’ existence is a challenge to models of planetary climate evolution. We report results indicating that, for a given catchment area, rivers on Mars were wider than rivers on Earth today. We use the scale (width and wavelength) of Mars paleo-rivers as a proxy for past runoff production.

The second in a series of USGS Southwest Region (SWR) “Science Exchange” annual workshops, focused on USGS drought science. The participants considered how extreme drought conditions are evolving in much of the American southwest, with an emphasis on integrated drought science planning at the USGS bureau and program levels. The increased need for interdisciplinary science to support resource-manag

Hundreds of new impact craters have been observed to form on Mars since spacecraft began imaging that planet. New impact craters produced visible ejecta deposits and many of them also have visible rays, similar to lunar and mercurian craters. However, some of the new martian impact craters have a circular feature of relatively low reflectance that we call a “halo.” This feature is distinct from th

Recent robotic missions to Mars have offered new insights into the extent, diversity and habitability of the Martian sedimentary rock record. Since the Curiosity rover landed in Gale crater in August 2012, the Mars Science Laboratory Science Team has explored the origins and habitability of ancient fluvial, deltaic, lacustrine and aeolian deposits preserved within the crater. This study describes

The United States Geological Survey’s (USGS) Planetary Geologic Map Coordination Group (Flagstaff, Ariz.) surveyed planetary geoscience map makers and users to determine the importance, relevance, and usability of such products to their planetary science research and to current and future needs of the planetary science community. This survey was prepared because the planetary science community lac

Clastic pipes are cylindrical injection features that vertically crosscut bedding with sharp contacts. Terrestrial pipes have cylindrical morphologies, massive or radially graded interiors, and raised outer rims. Increased grain size and subsequent cementation along the more porous edges makes the rims more resistant to weathering. Pipes have crosscutting relationships with other pipes due to mult

The innermost ring in impact basins exposes material originating from various depths, and can be used to study the composition of the lunar crust with depth. In this study, we conduct quantitative mineralogical analyses of the innermost ring in 13 lunar impact basins using reflectance data from the Kaguya Multiband Imager and radiative transfer modeling. We use results from recent hydrocode modeli

A decade of high-resolution monitoring has revealed extensive activity in fresh Martian gullies. Flows within the gullies are diverse: they can be relatively light, neutral or dark, colourful or bland, and range from superficial deposits to 10 m-scale topographic changes. We observed erosion and transport of material within gullies, new terraces, freshly eroded channel segments, migrating sinuous