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

Introduction: The density of impact craters is widely used in planetary science to study relative and absolute surface ages and the nature of resurfacing on planets. On Venus, the applicability of such methods is very limited due to the small total number of impact craters (about a thousand) [1-3], which is caused both by shielding with a thick atmosphere and active volcanic/tectonic resurfacin...

The depth and duration of energy and momentum coupling in an impact shapes the formation of the crater. The earliest stages of crater growth (when the projectile transfers its energy and momentum to the target) are unrecoverable when the event is described by late stage parameters, which collapse the initial conditions of the impact into a singular point in time and space. During the coupling p...

Impact cratering is a common geological process in the Solar System and most planetary bodies display geomorphologies strongly influenced by impacts (Lowman 1997). Fresh impact craters are normally characterized by a circular morphology (Melosh 1989). This surface expression is modified on Earth by active geological processes. The variation of terrestrial impact structure expressions suggests a...

Carbonate samples from the 8.9-Mt nuclear (near-surface xplosion) crater, OAK, and a terrestrial impact crater, Meteor Crater, were analyzed for shock damage using electron paramagnetic resonance (EPR). Samples from below the OAK apparent crater floor were obtained from six boreholes, as well as ejecta recovered from the crater floor. The degree of shock damage in the carbonate material was ass...

2755. [19] Wieczorek, M. A. et al. (2013) Science 339, 671-675. Figure 1: Locations of floor-fractured craters [2] plotted on a basemap of crustal thickness [19]. Floor-fractured craters are preferentially located in regions of intermediate (20-30 km) crustal thickness. Mare deposits are located primarily on the lunar nearside and in regions of thinner crust. Figure 2: Crater Buch B (17.0°E, 39...

Introduction: Impact craters on the Moon (and other bodies) form and degrade over time resulting in a change in crater shape and hence an overall evolution in lunar topography. Modeling of crater erosion (e.g. [1, 2, 3]) enables the tracking of crater shape evolution with time and can be used to estimate the relative age of a particular crater. Intuitively, crater degradation results from the c...

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...

[1] Pedestal craters on Mars are defined by an outwardfacing scarp forming a plateau perched tens of meters above the surrounding terrain. Their origin has been attributed to impact armoring of the surface and subsequent removal of inter-crater terrain by either eolian deflation or sublimation of an ice-rich substrate. We identified 2696 pedestal craters between 60 N and 60 S latitude; 98% are ...