Introduction: Impact craters are the dominant feature on any planetary surface and this dominance is used for the estimation of age of planets by crater count [1]. Such dominance gathered attention to detect them automatically in DTM [2] and panchromatic [3] images. Most of the crater detection algorithm (CDA) fall short to classify the crater and extract contextual information (presence/absenc...

The objective of this study was to obtain a quantitative understanding of the crateting process over a broad range of conditions. Our approach was to numerically compute the evolution of impact induced flow fields and calculate the time histories of the key measures of crater geometry (e.g. depth, diameter, lip height) for 9 2 variations in planetary gravity (0 to 10 cin/s ), material strength ...

We have studied plasma formation and relaxation dynamics along with the corresponding topography modifications in fused silica and sapphire induced by single femtosecond laser pulses (800 nm and 120 fs). These materials, representative of high bandgap amorphous and crystalline dielectrics, respectively, require nonlinear mechanisms to absorb the laser light. The study employed a femtosecond tim...

The first images of the asteroid 243 Ida from Galileo show an irregular object measuring 56-kilometers by 24 kilometers by 21 kilometers. Its surface is rich in geologic features, including systems of grooves, blocks, chutes, albedo features, crater chains, and a full range of crater morphologies. The largest blocks may be distributed nonuniformly across the surface; lineaments and dark-floored...

We derived crater production functions and chronology functions of Phobos for two scenarios, which likely represent the end-members of its dynamical evolution. Case A assumes that Phobos has been in its current orbit about Mars since its formation. Case B assumes a recent capture of Phobos and the impact history of an average Main Belt Asteroid. We determined the age of an average surface to th...

Thermochemical models have predicted that Ceres, is to some extent, differentiated and should have an icy crust with few or no impact craters. We present observations by the Dawn spacecraft that reveal a heavily cratered surface, a heterogeneous crater distribution, and an apparent absence of large craters. The morphology of some impact craters is consistent with ice in the subsurface, which mi...

Introduction: Central pit craters are an unusual class of impact crater seen most commonly on the icy Galilean satellites and Mars. They are characterized by terraced rims and flattened floors with a pit at or near the center (see Fig 1). Their association with ice-rich surfaces has led most hypotheses for the origins of central pits to rely on the volatility or weakness of water ice [e.g. 1, 2...

patients and methods previously recorded data of 231 patients who underwent surgical closure of vsd between january 2009 and january 2012 at the rajaie cardiovascular medical and research center were retrospectively reviewed. vsd surgical repair was performed using continues suturing technique in group a patients (n = 163, 70.6%) and interrupted suturing technique in group b patients (n = 68, 2...

High temperature impact melt breccias from the Rochechouart (France) meteorite crater record a magnetization component with antipodal, normal and reverse polarities. The corresponding paleomagnetic pole for this component lies between the 220 Ma and 210 Ma reference poles on the Eurasian apparent polar wander path, consistent with the 214±8 Ma Ar/Ar age of the crater. Late Triassic tectonic rec...

The trajectory of the impacting asteroid is another issue of considerable debate and still unresolved. Historically, circular plan views of impact craters confounded many investigators who assumed a circular crater requires a vertical impact. They wondered why more craters are not elliptical. Gilbert and Barringer both realized that 45° impacts are the most probable trajectories for meteoritic ...