Crater size–frequency analyses have shown that the largest volcanic plains deposits on Mercury were emplaced around 3.7 Ga, as determined with recent model production function chronologies for impact crater formation on that planet. To test the hypothesis that all major smooth plains on Mercury were emplaced by about that time, we determined crater size–frequency distributions for the nine next...

The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The...

The Rochechouart impact crater in the French Massif Central, has a diameter of 20 25 km [1] and an age of 250 my [2]. The cater is deeply eroded, down to the crater floor. Impact melt outcrops can be found in different parts of the crater [3]. The type of impactor that produced Rochechouart crater is still not clear. The first proposal of an IIA iron asteroid was based on the abundance of some ...

Shuttle Radar Topography Mission (SRTM) and Ground Penetrating Radar (GPR) data collected over an area north of the town of Hico, central Texas, have been used to map disturbances in the surface topography and subsurface stratigraphy. The Radar topography results confirm the presence of multiple rings suggestive of an impact crater. Correlation between the orbital SRTM and on-the-ground GPR fie...

The NEAR Shoemaker images provided the first reliable observations of sub-100 m craters on an asteroid. Veverka et al. [1] and Chapman et al. [2] found that much of the surface approached "empirical saturation", but at sizes below about 100-200 m the crater density was progressively lower than predicted for nearly saturated surfaces and did not have a slope expected of production populations. W...

We undertook a photogeologic study of Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images of the ejecta of the very young 22-km diameter crater Giordano Bruno (GB) and for the Luna 24 landing site region, where secondary craters from Giordano Bruno are observed. Using the technique of Basilevsky (1976) for estimating the absolute ages of small lunar craters based on thei...

Crater rays are formed during a cratering event as target material is ballistically ejected to distances of many crater radii forming narrow, generally high albedo, approximately linear features extending outward from the crater. The nature of crater rays was examined for the lunar crater Copernicus using new information on, the composition of surface material (from near-IR reflectance measurem...

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 mode of formation of gullies on Mars, very young erosional–depositional landforms consisting of an alcove, channel, and fan, is one of the most enigmatic problems in martian geomorphology. Major questions center on their ages, geographic and stratigraphic associations, relation to recent ice ages, and, if formed by flowing water, the sources of the water to cause the observed erosion/deposi...

Foreign object damage (FOD) occurs when hard, millimeter-sized objects such as gravel or sand and even the pieces of the engine components are ingested into aircraft jet engines. Particles impacting blades produce small indentation craters which can become sites for fatigue crack initiation, severely limiting the lifetime of the blade. In this study, the impact on the edge of a thin plate is in...