Introduction: Populations of impact craters are widely used in planetary science to study surface ages and the nature of resurfacing. Apparent surface age depends on scale; at smaller scales natural surfaces tend to be younger. High resolution imaging of Mars has revealed that at the scales of decameters and smaller, surprisingly many different terrains are devoid of small craters and hence are...

Introduction: Previous surveys have been conducted of the Venusian and lunar impact crater populations in an effort to empirically determine the onset angle of various oblique impact forms. Those surveys showed a general consistency with predictions from small-scale experiments [1,2,3]. That previous work also showed that in the presence of a dense atmosphere the onset angle increases for vario...

Introduction: Most studies of martian erosion have focused on crater statistics, aeolian landforms and deposits, and valley network morphology. Previous workers have noted that the martian crater population is deficient in craters less than ~30 km in diameter, presumably due to erosion [1], and that ancient martian craters were subjected to different erosional processes than craters on airless ...

We performed numerical simulations of impact crater formation on Europa to infer the thickness and structure of its ice shell. The simulations were performed using iSALE to test both the conductive ice shell over ocean and the conductive lid over warm convective ice scenarios for a variety of conditions. The modeled crater depth-diameter is strongly dependent on the thermal gradient and tempera...

Introduction: Counting craters has long been widely used in planetary science to get information about age of materials and events in geological history of planetary bodies. It also has long been understood that the uniform surface age and accumulation crater population requires "random" spatial distribution of craters. Such tests for randomness were applied to martian craters, e.g., in [1]. He...

Introduction: There is abundant geomorphic evidence for the importance of groundwater in the Martian hydrologic cycle. It appears likely that the valley networks formed as a result of groundwater sapping [1], and it is clear that the outflow channels are the manifestation of large-scale eruptions of groundwater to the surface [2]. Thus, our understanding of the formation of these features is on...

Dynamic compaction is a soil improvement method which has been widely used for the increase of bearing capacity through stress wave propagation during heavy tamping. The cost and time of project implementation can be effectively curtailed by developing a model that can be used in the design of dynamic compaction operations. The numerical models offered so far are mostly one or two-dimensional, ...

A 500 km long network of valleys extends from Herschel crater to Gale, Knobel, and Sharp craters. The mineralogy and timing of fluvial activity in these watersheds provide a regional framework for deciphering the origin of sediments of Gale crater’s Mount Sharp, an exploration target for the Curiosity rover. Olivine-bearing bedrock is exposed throughout the region, and its erosion contributed t...

By using high-resolution altimetric measurements of the Moon, we produced a catalog of all impact craters ≥20 kilometers in diameter on the lunar surface and analyzed their distribution and population characteristics. The most-densely cratered portion of the highlands reached a state of saturation equilibrium. Large impact events, such as Orientale Basin, locally modified the prebasin crater po...

The Bedout High, located on the northwestern continental margin of Australia, has emerged as a prime candidate for an end-Permian impact structure. Seismic imaging, gravity data, and the identification of melt rocks and impact breccias from drill cores located on top of Bedout are consistent with the presence of a buried impact crater. The impact breccias contain nearly pure silica glass (SiO2)...