[1] Several domes indicative of non-mare volcanism, morphologically as well as spectrally distinct from surrounding mare and highland units, are located in the Gruithuisen region in northern Oceanus Procellarum. The determination of the nature and age of non-mare volcanism helps to put constraints on lunar crustal evolution. The ages of the domes were previously thought to be mid-Imbrian or pos...

The four largest well-preserved impact basins in the solar system, Borealis, Hellas 16 and Utopia on Mars, and South Pole-Aitken on the Moon, are all significantly elongated, with 17 aspect ratios >1.2. This population stands in contrast to experimental studies of impact cratering 18 that predict <1% of craters should be elliptical, and the observation that ~5% of the small crater 19 population...

Reevaluating the geologic history of the prior Mars landing sites provides important ground truth for recent and ongoing orbital missions. At the Viking 2 Lander (VL2) site, topographic measurements of relict landforms indicate that at least 100 m of sedimentary mantle material has been stripped away. The observed paucity of impact craters <100 m in diameter suggests that resurfacing processes ...

Introduction: The Catalog of Large Martian Impact Craters [1] was compiled from Viking 1:2M photomosaics around 1980 and contains information on 42,283 craters generally ≥5-km-diameter across the entire Martian surface. The Catalog is undergoing revision using MGS (MOLA) and Odyssey (THEMIS) data. We have completed the initial revision of northern hemisphere craters, updating latitude and longi...

Divergent selection is the main driving force in sympatric ecological speciation and may also play a strong role in divergence between allopatric populations. Characterizing the genome-wide impact of divergent selection often constitutes a first step in unravelling the genetic bases underlying adaptation and ecological speciation. The Midas cichlid fish (Amphilophus citrinellus) species complex...

Recent advances in computing technology and our understanding of the processes involved in crater production, ejecta production, and crater erasure have permitted me to develop a highly-detailed Cratered Terrain Evolution Model (CTEM), which can be used to investigate a variety of questions in the study of impact dominated landscapes. In this work, I focus on the manner in which crater densitie...