Introduction: The early Late Devonian, wet-target Alamo Event at southern Nevada resulted in one of the best-exposed and well-dated impact deposits ever documented, the Alamo Breccia [1]. Because post-impact geologic processes have modified, obscured [2, 3] and perhaps wiped away its original morphological and architectural relationships, the crater stratigraphy has remained uncertain. Thus, th...

1 The Deep Impact Discovery Mission M. F. A’Hearn , L.A. McFadden, C.M. Lisse, D.D. Wellnitz (U.Md), M.J.S. Belton, (Belton Space Initiatives), A. Delamere (Ball Aerospace and Technologies Corp), K.P. Klaasen (JPL), J.Kissel (MPI), K.J. Meech (U.Hawaii), H.J. Melosh (U. Arizona), P.H. Schultz (Brown U.), J.M. Sunshine (SAIC), J. Veverka (Cornell U.), and D.K. Yeomans (JPL) The Deep Impact missi...

Peak-ring basins represent an impact-crater morphology that is transitional between complex craters with central peaks and large multi-ring basins. Therefore, they can provide insight into the scale dependence of the impact process. Here the transition with increasing crater diameter from complex craters to peak-ring basins on Mercury is assessed through a detailed analysis of Eminescu, a geolo...

Introduction: Impact craters are very helpful for studies of many aspects of surface processes on the Solar system bodies. Here we analyze population of impact craters in the Northern Lowlands of Mars, more specifically, within the typical Vastitas Borealis Formation (VBF) [1]. This is the largest geological unit on Mars. It is thought to have rather uniform age approximately at the Hesperian/A...

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...

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 ...

Introduction: The young Lonar crater, Maharashtra, India [1-3], is a bowl-shaped, almost circular, simple impact crater [4] of relatively small diameter ~1.8 km [5]. The uniqueness of this crater is that it is one of two known terrestrial impact craters excavated on basaltic target rock. The target-rock of this crater is the sub-horizontal Deccan basalt flows (~67 M.y.) [6]. All around the circ...

Introduction: The Bosumtwi Impact Crater in Ghana, Africa (6°32’N, 1°25’W) is a large complex crater. The crater is 10.5 km in diameter, with a central uplift 2 km in diameter. It is the source of the Ivory Coast Tektite field, found to the southwest of the crater over 200 km away. This study investigates the mineralogy, the petrology, and the geochemistry of drill core samples taken near the c...

The effects of a high-velocity impact on the microstructure, phase transformation and mechanical property of aged Ti49Ni51 alloy are investigated. The transformation behavior and microstructure along the impact direction after impact emerge with regionalization characteristics, including a deformed region near the crater (0-4 mm) and an un-deformed region of the distal crater (5-6 mm). Stress-i...

The NASA Discovery Deep Impact mission involves a unique experiment designed to excavate pristine materials from below the surface of comet. In July 2005, the Deep Impact (DI) spacecraft, will release a 360 kg probe that will collide with comet 9P/Tempel 1. This collision will excavate pristine materials from depth and produce a crater whose size and appearance will provide fundamental insights...